JP7200334B2 - Image forming device and management system - Google Patents

Description

The present invention relates to an electrophotographic image forming apparatus and a management system for managing a plurality of image forming apparatuses, and more particularly to notification of error information of an image forming apparatus.

2. Description of the Related Art In an optical scanning device used in an electrophotographic image forming apparatus, a rotating polygonal mirror driven by a scanner motor is used to deflect laser light that scans a photosensitive member. Activation control of the scanner motor at the start of printing will be described. First, when a start signal instructing the start of printing is input, the scanner motor starts rotating at full speed from a stopped state. Generally, a motor used as a scanner motor has a Hall element for detecting the position of the rotor, and the rotation speed of the scanner motor is detected by measuring the period of the FG signal output by the Hall element. be able to. Then, when the rotation speed of the scanner motor detected based on the FG signal reaches a predetermined speed, lighting of the laser is started. When the laser is turned on, a beam detector that detects the laser beam outputs a BD (beam detect) signal, which is a write detection signal for scanning the photoreceptor. By controlling the speed of the scanner motor based on the rotational speed detected by measuring the period of the BD signal, more accurate rotational speed control can be performed. Next, the phase control of the BD signal and the reference signal is performed in order to match the writing position of each color (each photoreceptor). Then, when it is detected that the phases of the reference signal and the BD signal match, a phase lock signal is output and image formation is started.

Further, the control unit of the image forming apparatus measures the time from the start of rotation of the scanner motor of the optical scanning device to the output of the phase lock signal, and if the phase lock signal is not output within the predetermined time, , it is determined that the scanner motor is abnormal. Then, the controller displays an error and stops the image forming operation. However, even in the case of an abnormality such as a laser diode, it may be erroneously determined to be an abnormality of the scanner motor. Therefore, for example, in Patent Document 1, means for determining the rotation state of the scanner motor and means for detecting the output state of the laser light detector are provided, and the scanner motor is detected based on the rotation state of the scanner motor and the output state of the laser beam. A method has been proposed for determining whether or not there is an abnormality.

JP-A-9-123519

However, in the conventional example described above, even if the scanner motor cannot be started because the voltage supplied from the power supply device is lowered when the scanner motor is started, and as a result, the phase lock signal is not generated within the predetermined time, It is determined that the scanner motor is abnormal. As described above, the scanner motor is started up through several control modes, but if phase lock is not achieved, an error indication will be given to indicate that the scanner motor is abnormal, regardless of which control mode causes an abnormality. was Even if the scanner motor is actually displayed as an abnormality due to an abnormality in the power supply rather than the scanner motor, the error display indicates that the scanner motor is abnormal, so operators and service personnel recognize that the scanner motor is abnormal. Resulting in. As a result, there is a problem that it takes a lot of time and labor for an operator or a service person to find out the cause of the abnormality of the optical scanning device and deal with it.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an accurate notification that an optical scanning device does not start due to an abnormality in the power supply of an image forming apparatus.

In order to solve the above problems, the present invention has the following configuration.

(1) a photoreceptor, a light source that emits a laser beam, a rotating polygonal mirror that deflects the laser beam so that the laser beam scans the photoreceptor, a drive motor that rotates the rotating polygonal mirror , and the an image forming unit for forming an image by developing an electrostatic latent image formed on the photosensitive member with toner; and electric power to the driving motor . and an overcurrent protection circuit that controls the supply of the current so that the current is not supplied from the power supply to the drive motor when the current output from the power supply is greater than a predetermined value. detection means for detecting whether or not current is supplied from the power supply to the drive motor in a state in which the control means is performing control to rotate the drive motor; and the control means controls the drive motor. If the detecting means detects that no current is being supplied from the power supply device to the drive motor when the rotation control is performed and the rotating polygon mirror does not reach the target speed within a predetermined time, the a notification means that does not notify the abnormality of the optical scanning device and notifies the abnormality of the optical scanning device when the detecting means detects that the electric current is being supplied from the power supply to the driving motor ; and an image forming apparatus.

(2) A management system comprising: a plurality of image forming apparatuses according to (1); and a management apparatus connected to the plurality of image forming apparatuses via a network line, wherein the image forming apparatus and transmitting the error information to the management device, the management device having a display device for displaying information, analyzing the error information received from the plurality of image forming devices, and displaying the error information on the display device. A management system characterized by

According to the present invention, it is possible to accurately notify that the optical scanning device will not start due to an abnormality in the power supply of the image forming apparatus.

FIG. 2 is a sectional view showing the configuration of the image forming apparatus of Examples 1 and 2; Schematic diagrams of essential parts for explaining the configuration of the optical scanning devices of Examples 1 and 2. FIG. 2 is a block diagram for explaining control of the scanner motors of the first and second embodiments; 4 is a flow chart showing a startup sequence of the scanner motor of the first embodiment; 4 is a flow chart showing a sequence for monitoring the activation state of the scanner motor according to the first embodiment; 10 is a flow chart showing a rotation state monitoring sequence after startup of the scanner motor according to the second embodiment; The figure which shows the management system of Example 1, 2

BEST MODE FOR CARRYING OUT THE INVENTION Below, embodiments of the present invention will be described in detail with reference to the drawings. Prior to describing embodiments of the present invention, problems in detecting an abnormality in an optical scanning device will be described. 2. Description of the Related Art In an optical scanning device used in an electrophotographic image forming apparatus, a rotating polygonal mirror driven by a scanner motor is used to deflect laser light scanned on a photoreceptor. for example,
RPM: number of revolutions per minute of the scanner motor (also the number of revolutions of the rotating polygon mirror)
PS: moving speed per second of the photoreceptor surface in a direction substantially perpendicular to the scanning direction of the laser beam (process speed)
DPI: resolution (number of dots per inch (25.4 mm))
When N is the number of faces of the rotating polygon mirror and M is the number of laser beams of the light source, the number of rotations of the scanner motor is expressed by the following relational expression.

RPM = ((PS x 60) x (DPI/25.4))/(M x N)
From this formula, it can be seen that in recent years efforts have been made to increase the number of rotations of the scanner motor in order to improve productivity (improve process speed) and improve resolution (DPI) for improving image quality.

On the other hand, the scanner motor requires a predetermined start-up time to reach the target number of rotations from the stopped state. The start-up time increases as the number of revolutions increases, and the problem is that the first printout time from when the command to start printing to when the first sheet of recording paper is printed and ejected increases (extends). is occurring. Therefore, in order to prevent an increase in the first printout time, a configuration is adopted in which the start-up time is shortened by increasing the rotation torque at start-up by increasing the current supplied to the scanner motor.

A power supply that supplies power to a scanner motor needs to have a large power supply capacity because the output current to the load increases. As the power supply capacity increases, the overcurrent that flows when the load is abnormal also increases. Therefore, an overcurrent protection circuit is provided to suppress the output current when an overcurrent is detected. For the safety of the device on the connected load side, the protective characteristics of the overcurrent protection circuit are also changed from the drooping characteristics of the limiter current that continues to flow after an overcurrent is detected to the folding back characteristics that reduce the current in an abnormal Shutdown characteristics or the like are sometimes used to stop current supply.

Further, an in-line color image forming apparatus having an image forming unit for each toner color may include an optical scanning device corresponding to each photoreceptor in order to expose a plurality of photoreceptors. The optical scanning device has a rotating polygonal mirror that deflects laser light that exposes the photosensitive member, and a scanner motor that rotates the rotating polygonal mirror. For example, an image forming apparatus having a configuration in which each optical scanning device exposes the photoreceptor of each image forming unit for four colors of yellow, magenta, cyan, and black has a total of four scanner motors. Become. An image forming apparatus starts forming an image after a scanner motor of an optical scanning device reaches a target rotation speed. At this time, in order to shorten the first printout time, it is necessary to start four scanner motors at the same time even when images are formed on the photoreceptors in the order of yellow, magenta, cyan, and black. The startup time of the scanner motor varies depending on temperature, power supply voltage, individual variation, and the like. Therefore, by starting image formation after confirming that all the scanner motors have reached the target rotation speed, the image formation timing of each color can be synchronized and the registration of each color can be adjusted. When four scanner motors are started almost simultaneously to shorten the first printout time, it is necessary to supply four times as much current from the power supply as when one scanner motor is started. Therefore, when the scanner motor is started, there is a high possibility that the overcurrent protection circuit will be activated, and the necessary power will not be supplied, which may cause the optical scanning device to not start normally.

Next, a description will be given of the problems associated with the error display notified when the optical scanning device is not started normally. As described above, the scanner motor requires a predetermined startup time to reach the target rotational speed from the stop state and enter the constant speed state. Here, the control when the scanner motor is started will be described. First, when a start signal instructing the start of printing is input, the controller of the image forming apparatus causes the scanner motor to start rotating at full speed from a stopped state. Generally, a motor used as a scanner motor is a three-phase brushless motor, and is provided with Hall elements for detecting changes in magnetic flux of magnetic poles provided on the rotor in order to detect the position of the rotor. Then, the rotation speed of the scanner motor is detected based on the FG signal, which is the rotor position detection signal output by the Hall element upon detection of the magnetic flux change. Then, when the rotation speed of the scanner motor detected based on the FG signal reaches a predetermined speed range, the light source starts turning on the laser (laser light emission). When the laser is turned on, a beam detector (BD) for detecting laser light outputs a BD signal, which is a write detection signal for scanning the photoreceptor. Since the BD signal is more accurate as a signal for detecting the rotation speed than the FG signal, after the BD signal is detected, the speed of the scanner motor is controlled based on the BD signal, thereby obtaining a more accurate rotation speed. can be controlled. Next, phase control of the BD signal is performed in order to match the writing position of each color (each photoreceptor). Since the BD signal is a signal for detecting the writing position of the rotating polygon mirror, the phase control circuit performs phase control using a clock signal generated in advance in accordance with each color as a reference signal for phase control, whereby the rotating polygon mirror of each color is detected. Mirrors can be matched in phase. When the phase control circuit detects that the phases of the reference signal and the BD signal match, it outputs a phase lock signal. When the controller of the image forming apparatus detects the phase lock signal, image formation is started.

Further, the control unit of the image forming apparatus measures the time from the start of rotation of the scanner motor to the output of the phase lock signal. If the phase lock signal is not output within a predetermined time, the controller determines that the scanner motor is abnormal, displays an error, and stops the image forming operation. At this time, the error display indicates an abnormality in the scanner motor. In fact, there may be cases where the scanner motor is not malfunctioning. For example, there are cases where the BD signal is not output due to malfunctioning of the laser diode, or the output voltage of the power supply is malfunctioning. Since the error display indicates that the scanner motor is malfunctioning, the operator or serviceman usually recognizes that the scanner motor is malfunctioning. However, in reality, even an abnormality in the power supply may be displayed as an abnormality in the scanner motor, so there is a problem that it takes a lot of time and effort to find the cause of the abnormality in the optical scanning device and to deal with it.

[Configuration of Image Forming Apparatus]
FIG. 1 is a diagram showing the configuration of an image forming apparatus for obtaining a color image according to the first embodiment. A basic description of an image forming apparatus and image formation will be given with reference to FIG. The color image forming apparatus has two cassette paper feed units 1 and 2 and one manual paper feed unit 3 . Transfer paper S, which is a recording medium, is selectively fed from cassette paper feed units 1 and 2 and manual paper feed unit 3 (hereinafter simply referred to as paper feed units 1, 2 and 3). The transfer sheets S are stacked on the cassettes 4, 5 or trays 6 of the respective paper feed units 1, 2, 3, and picked up by the pickup roller 7 toward the conveying path in order from the uppermost transfer sheet S. Of the transfer sheets S fed out by the pickup roller 7, only the uppermost transfer sheet S is separated by a separation roller pair 8 consisting of a feed roller 8A as a conveying means and a retard roller 8B as a separation means. After that, the transfer paper S is sent to the registration roller pair 12 which stops rotating. In this case, the transfer paper S fed from the cassettes 4 and 5 having a long distance to the registration roller pair 12 is relayed by a plurality of conveying roller pairs 9 , 10 and 11 and sent to the registration roller pair 12 . The transfer paper S fed to the registration roller pair 12 is temporarily stopped when the tip of the transfer paper hits the nip portion of the registration roller pair 12 and forms a predetermined loop. By forming this loop, the skewed state of the transfer sheet S is corrected.

A long intermediate transfer belt 13 serving as an intermediate transfer member is provided on the downstream side of the pair of registration rollers 12 in the conveying direction of the transfer sheet S (hereinafter simply referred to as the downstream side). The intermediate transfer belt 13 is stretched around a drive roller 13a, a secondary transfer opposing roller 13b, and a tension roller 13c, and is set to have a substantially triangular shape in cross section. The intermediate transfer belt 13 rotates clockwise in the figure. Photoconductive drums 14 , 15 , 16 , and 17 , which are a plurality of photoreceptors for forming and carrying color toner images of different colors, are arranged sequentially along the rotation direction of the intermediate transfer belt 13 on the upper surface of the horizontal portion of the intermediate transfer belt 13 . are placed. The most upstream photosensitive drum 14 in the rotation direction of the intermediate transfer belt 13 carries a magenta (M) toner image. The next photosensitive drum 15 carries a cyan (C) toner image. The next photosensitive drum 16 carries a yellow (Y) toner image. The most downstream photosensitive drum 17 in the rotation direction of the intermediate transfer belt 13 carries a black (B) toner image.

An optical scanning device 22 (indicated by a dashed-dotted frame in the drawing), which is an exposure device, is provided above each of the photosensitive drums 14, 15, 16, and 17 in the drawing. The optical scanning device 22 includes exposure units 22a, 22b, 22c, and 22d that irradiate laser beams LM, LC, LY, and LB to form electrostatic latent images and face photosensitive drums 14, 15, 16, and 17. It is set in a position where Details of the optical scanning device 22 will be described later.

Image formation in the image forming apparatus shown in FIG. 1 is performed as follows. First, the uppermost photosensitive drum 14 (on the photosensitive member) of the intermediate transfer belt 13 is exposed to a laser beam (which is also a light beam) LM based on a magenta component image, and an electrostatic latent image is formed on the photosensitive drum 14 . to form The electrostatic latent image formed on the photosensitive drum 14 is visualized by magenta toner supplied from the developing device 23 . Next, after a predetermined time has passed since the start of exposure of the laser beam LM onto the photosensitive drum 14, exposure of the photosensitive drum 15 with the laser beam LC based on the image of the cyan component is started, and an electrostatic charge is applied onto the photosensitive drum 15. form a latent image. The electrostatic latent image formed on the photosensitive drum 15 is visualized by cyan toner supplied from the developing device 24 . Subsequently, after a predetermined time has elapsed since the start of exposure of the laser beam LC onto the photosensitive drum 15, exposure of the photosensitive drum 16 with the laser beam LY based on the image of the yellow component is started, and an electrostatic charge is applied onto the photosensitive drum 16. form a latent image. The electrostatic latent image formed on the photosensitive drum 16 is visualized by yellow toner supplied from the developing device 25 . Finally, after a predetermined time has passed since the start of exposure of the laser beam LY onto the photosensitive drum 16, exposure of the photosensitive drum 17 with the laser beam LB based on the image of the black component is started, and an electrostatic charge is applied onto the photosensitive drum 17. form a latent image. The electrostatic latent image formed on the photosensitive drum 17 is visualized by black toner supplied from the developing device 26 . Primary chargers 27, 28, 29 and 30 for uniformly charging the photosensitive drums 14-17 are provided around the photosensitive drums 14-17. Cleaners 31, 32, 33, and 34 are also provided for removing toner adhering to the photosensitive drums 14 to 17 after the toner images have been transferred.

While the intermediate transfer belt 13 rotates clockwise, the intermediate transfer belt 13 passes through the transfer portion between the photosensitive drum 14 and the transfer charger 90 , thereby forming a magenta toner image on the intermediate transfer belt 13 . is transcribed. Next, the intermediate transfer belt 13 passes through the transfer portion between the photosensitive drum 15 and the transfer charger 91 , thereby transferring a cyan toner image onto the intermediate transfer belt 13 . Subsequently, the intermediate transfer belt 13 passes through the transfer portion between the photosensitive drum 16 and the transfer charger 92 , thereby transferring a yellow toner image onto the intermediate transfer belt 13 . Finally, the intermediate transfer belt 13 passes through the transfer portion between the photosensitive drum 17 and the transfer charger 93 , thereby transferring the black toner image onto the intermediate transfer belt 13 . The transfer of the toner images of the respective colors from the photosensitive drums 14 to 17 to the intermediate transfer belt 13 is performed with proper timing, and the toner images of magenta, cyan, yellow, and black are superimposed on the intermediate transfer belt 13 . be transcribed.

On the other hand, the transfer sheet S is sent to the registration roller pair 12 to correct the skew. The pair of registration rollers 12 start rotating at the timing when the positions of the toner image on the intermediate transfer belt 13 and the leading edge of the transfer paper S are aligned. Next, the transfer sheet S is sent by the pair of registration rollers 12 to the transfer portion T2, which is the contact portion between the secondary transfer roller 40 on the intermediate transfer belt 13 and the secondary transfer opposing roller 13b. A toner image is transferred. The transfer sheet S that has passed through the transfer section T2 is sent to a fixing device 35 as fixing means. While the transfer sheet S passes through the nip formed by the fixing roller 35A and the pressure roller 35B in the fixing device 35, it is heated by the fixing roller 35A and pressed by the pressure roller 35B to form a toner image. is fixed on the transfer paper S. The transfer paper S that has passed through the fixing device 35 and has undergone the fixing process is conveyed to a discharge roller pair 37 by a conveying roller pair 36 and further discharged onto a discharge tray 38 outside the apparatus. Note that the color image forming apparatus in FIG. 1 is an example, and may be, for example, a monochrome image forming apparatus, and is not limited to the configuration of this embodiment.

The control unit 130 controls each device to perform the image forming operation described above. The power supply device 150 generates DC (direct current) 5V to be supplied to the control system such as the controller 130 and the controller 114 to be described later, and DC 24V to be supplied to the load of the driving system such as the motor. Furthermore, the upper portion of the image forming apparatus is provided with an operation unit 140 having an input unit for inputting data and a display unit for displaying information.

[Configuration of Optical Scanning Device]
FIG. 2 is a schematic diagram showing a scanning optical system of an exposure unit for one color in the optical scanning device 22 of FIG. 1 and its peripheral configuration. The optical scanning device 22 includes exposure units 22a, 22b, 22c, and 22d for four colors, and the configuration and operation of each exposure unit are the same. The operation of the exposure section 22b for forming an electrostatic latent image on the surface of the laser will be described.

The image forming apparatus shown in FIG. 1 irradiates the photosensitive drum 15 with a laser beam LC so as to form an electrostatic latent image corresponding to input image data on the photosensitive drum 15, as shown in FIG. An optical scanning device 22 having an exposure unit 22b for scanning is provided. The optical scanning device 22 has a laser light source LD100 that emits 16 beams of laser light. A plurality of laser lights emitted from the laser light source LD100 become parallel laser light LC via a collimator lens 1013 . The laser beam LC is incident on the reflecting surface of a rotary polygon mirror 1002 which is a deflection means rotated by a scanner motor 1003 . Then, the rotating polygon mirror 1002 reflects the laser light LC so that the laser light LC incident on the reflecting surface scans the photosensitive drum 15 . The laser light LC reflected by the rotating polygon mirror 1002 passes through the Fθ lens 1014 and scans the surface of the photosensitive drum 15 at a constant speed in the main scanning direction (the arrow direction in the drawing). An electrostatic latent image 1016 is formed on the photosensitive drum 15 by scanning with the laser light LC.

At the timing when the laser light LC starts scanning the photosensitive drum 15, the laser light source LD100 is forcibly turned on, and the laser light LC reflected by the rotating polygon mirror 1002 enters the beam detector 1017 (hereinafter referred to as BD1017). The BD 1017 detects the laser light LC reflected by the rotating polygon mirror 1002 and input during the forced lighting period of the laser light source LD 100, and generates a beam detect signal (hereinafter referred to as a BD signal) that serves as a reference signal for image writing timing in the main scanning direction. ).

[Control of Drive Motor of Optical Scanning Device]
FIG. 3 is a block diagram for explaining control of the scanner motor 1003 of the optical scanning device 22. As shown in FIG. FIG. 3 shows a power supply unit 150 for supplying electric power, a controller 114 for controlling the scanner motor 1003, a controller board 114a for mounting a speed control circuit and a phase control circuit, and control of the optical scanning device 22 for mounting the scanner motor 1003 and control circuit 109. showing relationships. In this embodiment, controllers 114 are provided for the exposure units 22a, 22b, 22c, and 22d of the optical scanning device 22, respectively.

The optical scanning device 22 has a scanner motor 1003, a control circuit 109, a bridge circuit 108, and a BD 1017, as shown in FIG. The scanner motor 1003 has a rotor 101 which is a rotor portion, and the rotating polygon mirror 1002 shown in FIG. The scanner motor 1003 is a 3-phase 4-pole brushless DC motor. The rotor 101 is equipped with a magnet in which two sets of magnetic poles (N pole, S pole) are arranged. Rotor 101 is rotated by a rotating magnetic field generated by field windings 105, 106 and 107, and as rotor 101 rotates, rotating polygon mirror 1002 on rotor 101 also rotates.

As the scanner motor 1003 rotates (that is, as the rotor 101 rotates), the magnetic flux around the Hall elements 102, 103, 104 changes. Hall elements 102 , 103 , and 104 as signal generating means detect changes in the magnetic flux magnetized in rotating rotor 101 and output detection signals to control circuit 109 . The control circuit 109 detects the magnetic pole positions of the magnets provided on the rotor 101 from the detection signals output from the Hall elements 102, 103, and 104, and controls the bridge circuit 108 to generate a rotating magnetic field corresponding to the magnetic pole positions. Outputs the drive signal. Bridge circuit 108 supplies voltage Vcc (24 VDC) supplied from power supply 150 to field windings 105 , 106 , 107 of scanner motor 1003 according to the drive signal input from control circuit 109 . Thus, in the optical scanning device 22, the magnetic pole position of the rotor 101 is detected from the outputs from the Hall elements 102, 103, and 104, and the control circuit 109 supplies electric power to the field windings 105, 106, and 107 at optimum timing. switch supply. As a result, the scanner motor 1003 generates a rotating magnetic field, and the rotor 101 is rotationally driven.

A controller substrate 114a of the controller 114 is provided with an acceleration/deceleration signal switching circuit 110, a phase control circuit 111, speed control circuits 112 and 113, and the controller 114. FIG. A controller 114 , which is control means, controls the scanner motor 1003 by controlling the acceleration/deceleration signal switching circuit 110 , the phase control circuit 111 , and the speed control circuits 112 and 113 . The controller 114 also has a timer (not shown) for measuring time. The output of the Hall element 102 is also supplied to the speed control circuit 113 as an FG signal (rotation cycle signal). The frequency of the FG signal is proportional to the rotational speed of rotor 101 . Therefore, the rotation speed of the scanner motor 1003 can be controlled by controlling the electric power supplied to the scanner motor 1003 so that the frequency of the FG signal becomes a predetermined frequency corresponding to the target rotation speed of the scanner motor 1003. . The speed control circuit 113 generates an acceleration signal or a deceleration signal (hereinafter referred to as acceleration/deceleration signal) according to the rotation speed calculated from the FG signal so that the rotation speed of the scanner motor 1003 becomes the target rotation speed. Output to the signal switching circuit 110 . Further, the speed control circuit 113, which is a rotation detecting means, outputs a speed lock signal ( first lock signal) to the controller 114 . When starting the scanner motor 1003 , the controller 114 outputs a start signal to the speed control circuit 113 and outputs an acceleration/deceleration signal from the speed control circuit 113 to the acceleration/deceleration signal switching circuit 110 to the optical scanning device 22 . Outputs a switching signal that instructs to switch. As a result, an acceleration/deceleration signal for driving the scanner motor 1003 is output from the acceleration/deceleration signal switching circuit 110 to the control circuit 109 of the optical scanning device 22, and the scanner motor 1003 starts rotating.

A BD signal output from the BD 1017 as light beam detection means is supplied to the speed control circuit 112, the phase control circuit 111 and the controller 114. FIG. Since the BD signal, which is a detection signal, is proportional to the rotation speed of the rotor 101 like the FG signal output by the Hall element 102 and the like, it serves as a signal for detecting the rotation speed of the scanner motor 1003 . Therefore, the speed control circuit 112, which is rotation detection means, generates an acceleration/deceleration signal according to the rotation speed calculated from the BD signal so that the rotation speed of the scanner motor 1003 becomes the target rotation speed. output to When the speed control circuit 112 detects that the rotational speed of the scanner motor 1003 detected based on the BD signal has reached a predetermined rotational speed range, it outputs a speed lock signal (second signal) to the controller 114 . A predetermined rotation speed of the scanner motor 1003 when the speed control circuit 113 outputs the speed lock signal and a predetermined rotation speed of the scanner motor 1003 when the speed control circuit 112 outputs the speed lock signal are different rotational speeds. A phase control circuit 111 compares the phases of the reference clock signal output from the controller 114 and the BD signal, generates an acceleration/deceleration signal for the scanner motor 1003 so that the phases of the two signals are the same, and an acceleration/deceleration signal switching circuit. output to 110. Further, the phase control circuit 111, which is a phase control unit, sends a phase lock signal (third lock signal) to the controller 114 when the phase difference between the reference clock signal and the BD signal reaches within a predetermined range. Output. Note that the phase lock signal is output to the controller 114 when the phase difference between the reference clock signal and the BD signal is within a predetermined range.

The controller 114 detects the state of the scanner motor 1003 based on the phase lock signal output from the phase control circuit 111 and the speed lock signals output from the speed control circuits 112 and 113 . Then, the controller 114 outputs a switching signal instructing the acceleration/deceleration signal switching circuit 110 to output the acceleration/deceleration signal from the speed control circuit 112 or the speed control circuit 113 based on the detection result. The acceleration/deceleration signal switching circuit 110 outputs the acceleration/deceleration signals output from the speed control circuits 112 and 113 to the control circuit 109 of the optical scanning device 22 according to the switching signal output from the controller 114 . The control circuit 109 of the optical scanning device 22 controls the drive state of the scanner motor 1003 of the bridge circuit 108 according to the input acceleration/deceleration signal, and controls the amount of power supplied to the field windings 105, 106, and 107. , the rotation speed of the scanner motor 1003 is controlled. In addition, the controller 114 inputs a voltage obtained by dividing the power supply voltage Vcc (24 V DC) by voltage dividing resistors 115 and 116, which are voltage detection means, in order to detect the state of the power supply voltage Vcc (24 V DC) supplied to the optical scanning device 22. By doing so, the state of the power supply voltage is detected.

The power supply device 150 of this embodiment is attached to the main body of the image forming apparatus. The power supply device 150 has a voltage generator 150a and an overcurrent protection circuit 150b. The voltage generation unit 150 a generates 5 V DC (direct current voltage) to be supplied to the control circuit such as the controller 114 and 24 V DC to be supplied to the drive system such as the scanner motor 1003 . The overcurrent protection circuit detects the current value of the power supply voltage (24 VDC) supplied to the optical scanning device 22, and detects that a current exceeding a predetermined current value is being supplied to the optical scanning device 22 and the like. Cut off the supply or lower the current value. As a result, overcurrent supply to the optical scanning device 22, which is a load, is prevented.

[Startup Sequence of Optical Scanning Device]
Next, the control at the time of starting the scanner motor 1003 when performing image formation will be described. FIG. 4 is a flow chart showing a control sequence when the image forming apparatus starts the scanner motor 1003 of the optical scanning device 22 to perform an image forming operation. The processing shown in FIG. 4 is activated and executed by the controller 114 when the image forming apparatus performs an image forming operation.

At step (hereinafter referred to as S) 102 , the controller 114 sets the variable MODE indicating the control mode for activating the optical scanning device 22 to 0 representing the initial state. In S103, the controller 114 determines whether the voltage input to the controller 114 after dividing the power supply voltage Vcc by the voltage dividing resistors 115 and 116 before the scanner motor 1003 is started is in a power supply voltage abnormality state lower than a predetermined voltage. to decide. If the controller 114 determines that the input voltage is lower than the predetermined voltage (the power supply voltage is abnormal), the process proceeds to S118, and the input voltage is the predetermined voltage or higher (the power supply voltage is not abnormal). If so, the process proceeds to S104. In S118, the controller 114 performs the following power supply error processing. The controller 114 notifies the control unit 130 of the occurrence of a power supply error, and the control unit 130 displays the occurrence of the power supply error indicating the abnormality of the power supply unit 150 on the display unit of the operation unit 140, which is a user interface, and prints the image. Stop the start operation and end the process.

In S104, the controller 114 starts rotation control of the scanner motor 1003 of the optical scanning device 22 based on the FG signal (motor FG rotation control start). Therefore, the controller 114 outputs a start signal to the speed control circuit 113 to cause the speed control circuit 113 to output an acceleration/deceleration signal. Further, the controller 114 outputs a switching signal to the acceleration/deceleration signal switching circuit 110 to instruct the speed control circuit 113 to output the acceleration/deceleration signal from the speed control circuit 113 for controlling the speed of the scanner motor 1003 based on the FG signal. In S105, the controller 114 resets and starts a timer to monitor whether or not the activation process of the scanner motor 1003 is completed within a predetermined time (timer activation). In S106, the controller 114 sets the variable MODE to 1 indicating the FG rotation mode.

In S107, the controller 114 determines whether or not the scanner motor 1003 has reached the target rotation speed (first target rotation speed) (target rotation speed) based on the presence or absence of output of a speed lock signal from the speed control circuit 113 that controls the scanner motor 1003. Number reached?) Judge. When the controller 114 detects that the speed lock signal is output from the speed control circuit 113, the controller 114 determines that the scanner motor 1003 has reached the target rotational speed, and advances the process to S108. On the other hand, if the controller 114 does not detect the speed lock signal from the speed control circuit 113, it determines that the scanner motor 1003 has not reached the target rotation speed, and returns the process to S107. In S108, the controller 114 controls the laser light source LD100 of the optical scanning device 22 to start emitting laser light from the laser light source LD100 (laser lighting start). In S109, the controller 114 sets the variable MODE to 2 indicating the laser control mode in order to shift the control mode.

In S110, the controller 114 determines whether a laser beam is input to the BD 1017 and the BD 1017 is outputting a BD signal (BD detection?). If the controller 114 determines that the input of the BD signal from the BD 1017 has been detected, the process proceeds to S111, and if it determines that the BD signal from the BD 1017 has not been detected, the process returns to S110. . In S111, the controller 114 starts speed control of the scanner motor 1003 based on the BD signal (BD speed control start). Therefore, the controller 114 outputs a switching signal to the acceleration/deceleration signal switching circuit 110 to instruct the acceleration/deceleration signal switching circuit 110 to output the acceleration/deceleration signal from the speed control circuit 112 that controls the speed of the scanner motor 1003 based on the BD signal. In S112, the variable MODE is set to 3 indicating the BD speed control mode in order to shift the control mode.

In S113, the controller 114 determines whether or not the scanner motor 1003 has reached the target rotation speed (second target rotation speed) based on the presence or absence of the output of the speed lock signal from the speed control circuit 112 which controls the scanner motor 1003 by the BD signal. (Has the target speed been reached?) Judge. When the controller 114 detects the speed lock signal from the speed control circuit 112, the controller 114 determines that the scanner motor 1003 has reached the target rotational speed, and advances the process to S114. On the other hand, if the controller 114 does not detect the speed lock signal from the speed control circuit 112, the controller 114 determines that the scanner motor 1003 has not reached the target rotation speed, and returns the process to S113. In S114, the controller 114 starts phase control of the scanner motor 1003 based on the BD signal (BD phase control start). In S115, the controller 114 sets the variable MODE to 4 indicating the BD phase control mode in order to shift the control mode.

In S116, the controller 114 matches the phase of the BD signal with the phase of the reference clock signal of the black (B) exposure unit 22d, thereby determining whether the phase lock signal is output from the phase control circuit 111. Determine whether (phase locked?). When the phase lock signal from the phase control circuit 111 is detected, the controller 114 determines that the phases of the BD signal and the reference clock signal match, and advances the process to S117. On the other hand, when the phase lock signal from the phase control circuit 111 is not detected, the controller 114 determines that the phases of the BD signal and the reference clock signal do not match, and returns the process to S116. In S117, the controller 114 sets the variable MODE to 5 indicating the BD phase lock mode, and ends the process. After that, the controller 114 starts printing for forming an image on the transfer paper S. FIG.

[Error Monitoring at Startup of Optical Scanning Device]
Next, a process for monitoring whether or not the activation process of the scanner motor 1003 described with reference to FIG. 4 has been completed normally within a predetermined time will be described. FIG. 5 is a flow chart showing a control sequence for monitoring the activation state of the scanner motor 1003 of the optical scanning device 22. As shown in FIG. In the process shown in FIG. 5, when the timer is started in the process of S105 in FIG. Processing is performed.

In S202, the controller 114 determines whether the value set to the variable MODE is 5 (BD phase lock mode) (MODE=5?). When the controller 114 determines that the value set to the variable MODE is 5, the scanner motor 1003 of the optical scanning device 22 is normally activated, and the process ends. When the controller 114 determines that the value set in the variable MODE is not 5, the process proceeds to S203. In S203, the controller 114 refers to the timer started in the process of S105 of FIG. Whether (target time elapsed?) Judge. If the controller 114 determines that the target time has passed, the process proceeds to S204, and if it determines that the target time has not passed, the process proceeds to S208. In S208, the controller 114 stops processing (100 msec wait) for 100 msec (milliseconds), and after 100 msec has passed, returns to S202 and executes the processing. Instead of the process of S208, a timer (a timer different from the timer started in the process of S105 in FIG. 4) is reset and started, and it is determined whether or not the timer value has passed 100 msec, and it is determined that it has passed. In some cases, the process may be returned to S202.

In S204, the controller 114 again determines whether or not the input voltage obtained by dividing the power supply voltage Vcc by the voltage dividing resistors 115 and 116 is lower than a predetermined voltage (abnormal power supply voltage?). If the controller 114 determines that the input voltage is lower than the predetermined voltage (the power supply voltage is abnormal), the process proceeds to S210, and the input voltage is the predetermined voltage or higher (the power supply voltage is not abnormal). If so, the process proceeds to S205. In S210, the controller 114 performs the following power supply error processing. The controller 114 notifies the control unit 130 of the occurrence of the power supply error. The control unit 130 causes the display unit of the operation unit 140 to display a motor startup error indicating that the scanner motor 1003 has started abnormally, and a power supply failure mode indicating the mode in which the abnormality occurred, and start printing. Stop the operation and terminate the process.

In S205, the controller 114 determines whether or not the value of the variable MODE is 1 (FG rotation control mode). If it is determined that it is not, the process proceeds to S206. In S211, the controller 114 performs the following FG control error processing. The controller 114 notifies the control unit 130 of the occurrence of the FG control error. The control unit 130 displays on the display unit of the operation unit 140 that a motor startup error has occurred and the FG rotation control abnormal mode indicating the mode at the time of occurrence of the abnormality, stops the print start operation, and ends the process.

In S206, the controller 114 determines whether or not the value of the variable MODE is 2 (laser control mode). If it is determined that there is no, the process proceeds to S207. In S212, the controller 114 performs the following laser control error processing. Controller 114 notifies controller 130 of the occurrence of a laser control error. The control unit 130 displays on the display unit of the operation unit 140 that a motor start error has occurred and a laser control abnormality mode indicating the mode at the time of occurrence of the abnormality, stops the print start operation, and ends the process. In S207, the controller 114 performs the following BD control error processing. The controller 114 notifies the control unit 130 of the occurrence of the BD control error. The control unit 130 displays on the display unit of the operation unit 140 that a motor startup error has occurred and the BD control abnormality mode indicating the mode at the time of occurrence of the abnormality, stops the print start operation, and ends the process.

[Error code]
As described above, the controller 114 displays an error on the operation unit 140 when an abnormality occurs when the optical scanning device 22 is activated. Table 1 shown below is a table showing an example of error codes included in the error information displayed on the operation unit 140 .

Table 1 is composed of an error code column and a status column indicating an error location and an error state. The error code shown in the error code column is composed of a 5-digit hexadecimal code. If the error code is E1000, it indicates that the power supply voltage from the power supply device 150 is lower than a predetermined voltage (indicated as power supply abnormality in the figure). If the error code is E1010, it indicates that the scanner motor 1003 did not reach the target rotation speed in the FG control mode (indicated as FB control abnormality in the figure). Furthermore, when the error code is E1020, it indicates an abnormality in which the BD signal was not detected when the laser was turned on in the laser control mode of the scanner motor 1003 (displayed as laser control abnormality in the figure). If the lower 4-digit code is E1030, the scanner motor 1003 did not reach the target rotation speed, or the phase could not be adjusted after reaching the target speed. display).

As explained above, if an error occurs when the scanner motor starts up, it is determined whether the error is caused by the scanner motor or the power supply, based on the control mode when the error occurred. Information can be reported. As a result, the operator can accurately recover from the abnormal state of the optical scanning device based on the notified error information. In this embodiment, the control of the 1-in-1 optical scanning device in which the exposure unit for scanning the photosensitive drum is provided corresponding to the photosensitive drum has been described. It is possible to apply examples. Further, in this embodiment, a color image forming apparatus has been described as an example, but this embodiment can also be applied to a monochrome image forming apparatus having a single photosensitive drum.
As described above, according to this embodiment, it is possible to accurately notify that the optical scanning device does not start due to an abnormality in the power supply of the image forming apparatus.

In the first embodiment, the process of monitoring whether or not the scanner motor of the optical scanning device is normally activated within a predetermined target time during image formation, and notifying an error when it is not normally activated has been described. In a second embodiment, a process of monitoring the occurrence of an abnormality in the optical scanning device in the image forming apparatus after normal startup will be described. The configurations of the image forming apparatus and the optical scanning device in the second embodiment are the same as those in the first embodiment, and the same reference numerals are used for the same devices, and the description thereof is omitted here.

[Abnormality Monitoring after Startup of Optical Scanning Device]
FIG. 6 is a flow chart showing a control sequence for monitoring the operating state of the scanner motor 1003 of the optical scanning device 22. As shown in FIG. The process shown in FIG. 6 is a process that is started after the scanner motor 1003 is started, the phase control circuit 111 outputs a phase lock signal to the controller 114, and printing becomes possible in the process of FIG. 5 of the first embodiment. Yes, executed by the controller 114 . Once activated, the process of FIG. 7 is periodically (100 msec (milliseconds)) executed by the controller 114 .

In S302, the controller 114 sets the error counter N to zero. In S303, the controller 114 determines whether the phases of the BD signal and the reference clock signal match (phase locked?) based on whether the phase control circuit 111 outputs a phase lock signal. The controller 114 determines that the phase lock state is established when the phase lock signal is output from the phase control circuit 111, and advances the process to S304. On the other hand, if the phase control circuit 111 does not output the phase lock signal, the controller 114 determines that the phase lock state is not reached, and advances the process to S306. In S304, the controller 114 sets the error counter N to zero. In S305, the controller 114 stops processing for 100 msec (milliseconds), and after 100 msec has passed, returns to S303 and executes the processing.

In S306, the controller 114 adds 1 to the error counter N. In S307, the controller 114 refers to the value of the error counter N and determines whether the value of the error counter N is ten. If the value of the error counter N is 10, the controller 114 advances the process to S308 because the non-phase-locked state continues for one second (=100 msec×10 times) (second predetermined time). If the counter N is not 10, the process returns to S305. Here, when the value of the error counter N is 10, the error processing from S308 onwards is performed, but the value of the error counter N is not limited to 10 (the state in which the phase is not locked is 1 second). .

In S308, the controller 114 determines whether or not the input voltage to the controller 114 obtained by dividing the power supply voltage Vcc by the voltage dividing resistors 115 and 116 is lower than a predetermined voltage. If the controller 114 determines that the input voltage is lower than the predetermined voltage (the power supply voltage is abnormal), the process proceeds to S310, and the input voltage is equal to or higher than the predetermined voltage (the power supply voltage is not abnormal). If so, the process proceeds to S309. In S309, the controller 114 performs the following BD control error processing. The controller 114 notifies the control unit 130 of the occurrence of the BD control error. The control unit 130 displays, on the display unit of the operation unit 140, the occurrence of a motor error indicating that the scanner motor 1003 is abnormal after startup, and the BD control abnormality mode indicating the mode at the time of occurrence of the abnormality. and terminate the process. In S310, the controller 114 performs the following power supply error processing. The controller 114 notifies the control unit 130 of the occurrence of the power supply error. The control unit 130 displays on the display unit of the operation unit 140 that a power error has occurred indicating that the power supply device 150 is abnormal, stops the printing operation, and ends the process.

As described above, according to this embodiment, it is possible to accurately notify that the optical scanning device does not start due to an abnormality in the power supply of the image forming apparatus. Furthermore, it is possible to accurately notify the occurrence of an abnormality during execution of the image forming operation after the optical scanning device is started, due to an abnormality in the power supply device of the image forming apparatus.

In Embodiments 1 and 2, error notification when an abnormality occurs in the optical scanning device during image formation or during image formation has been described. When an image forming apparatus and a personal computer (hereinafter referred to as a PC) are connected to a network such as a LAN built in a company, printing is performed by the image forming apparatus according to a print instruction from the user's PC. In order to centrally manage a plurality of image forming apparatuses connected to a network, an embodiment will be described in which a host apparatus such as a PC is connected to the network and an operator monitors an abnormal state of each image forming apparatus.

[Network configuration]
FIG. 7 is a diagram showing the connection status between the plurality of image forming apparatuses 100, 200, and 300 and the host device 50 of this embodiment. Image forming apparatuses 100 , 200 , and 300 are all connected to network line 70 via network connection device 160 . The configurations and operations of the image forming apparatuses 100, 200, and 30 are the same as those described in the first and second embodiments, and the same components are denoted by the same reference numerals, and descriptions thereof are omitted. A host device 50 is connected to a network line 70 to centrally manage a plurality of image forming apparatuses. The host device 50 can collect error information such as an error code displayed on the operation unit 140 when an error occurs in the image forming apparatuses 100, 200, and 300 via the network line 70 by the control unit 50a. there is In the image forming apparatuses 100, 200, and 300, the network connection device 160 is connected to the control unit 130, and the control unit 130 displays error information on the operation unit 140 to inform the user when an abnormality occurs in the optical scanning device 22. notify. Furthermore, the image forming apparatuses 100 , 200 and 300 also transmit error information to the host device 50 via the network line 70 .

The host device 50 is connected to the same network line 70 as the image forming apparatuses 100, 200, and 300, and monitors the operation status of each image forming apparatus by receiving error information from the image forming apparatuses 100, 200, and 300. do. When the image forming apparatuses 100 , 200 , and 300 detect an abnormal state of the optical scanning device 22 , the image forming apparatuses 100 , 200 , and 300 transmit the error code described in the first embodiment and the identification number assigned to the image forming apparatus in which the abnormality has occurred to the host device 50 . When receiving the error information from the image forming apparatuses 100, 200, and 300, the control unit 50a of the host device 50 displays the error information on the display 50b of the host device 50 as follows. That is, since the error code is expressed in hexadecimal as described in the first embodiment, the control unit 50a analyzes the error code and displays the following information on the display device so that the operator can easily understand. displayed on the display 50b. For example, the identification number of the image forming apparatus in which the abnormality occurred, whether the apparatus in which the abnormality occurred was the power supply device 150 or the optical scanning device 22, and in the case where the abnormality occurred in the optical scanning device 22, whether it was at startup before image formation. , whether image formation is being executed is displayed. Further, when the optical scanning device 22 is activated before image formation, the control unit 50a determines whether the error occurred in the FG control mode, the laser control mode, or the BD control mode. Whether it is a time error or not is displayed on the display 50b. The operator can identify the location of the error in the image forming apparatus based on the error information displayed on the display 50b. As a result, the operator or serviceman can prepare a replacement for the power supply device 150 or the optical scanning device 22 in which an abnormality has been detected, and can promptly replace it.

As described above, by configuring a management system for monitoring image forming apparatuses for abnormalities, when an abnormality occurs in a plurality of image forming apparatuses, the image forming apparatus or optical scanning apparatus in which an abnormality has occurred can be identified and quickly corrected. can respond to recovery. As a result, it is possible to reduce the workload of operators and service personnel when an abnormality occurs.
As described above, according to this embodiment, it is possible to accurately notify that the optical scanning device does not start due to an abnormality in the power supply of the image forming apparatus.

14 to 17 photosensitive drum 22 optical scanning device 114 controllers 115, 116 resistor 150 power supply device 1002 rotary polygon mirror 1003 scanner motor

Claims (13)

a photosensitive member, a light source that emits a laser beam, a rotating polygon mirror that deflects the laser beam so that the laser beam scans the photosensitive member, a driving motor that rotates the rotating polygon mirror , and the driving motor an image forming unit that forms an image by developing an electrostatic latent image formed on the photoreceptor with toner;
a power supply that supplies power to the drive motor ;
an overcurrent protection circuit that controls the supply of the current so that the current is not supplied from the power supply to the drive motor when the current output from the power supply is greater than a predetermined value;
detection means for detecting whether current is being supplied from the power supply to the drive motor while the control means is controlling the rotation of the drive motor;
When the control means controls the rotation of the drive motor and the rotating polygon mirror does not reach the target speed within a predetermined time, the detection means detects that the current is not supplied from the power supply to the drive motor . is detected, the abnormality of the optical scanning device is not notified, and when the detection means detects that the electric current is being supplied from the power supply to the driving motor , the abnormality of the optical scanning device is detected. an informing means for informing the
An image forming apparatus comprising: The notifying means supplies current from the power supply to the driving motor when the control means controls the rotation of the driving motor and the rotating polygon mirror does not reach the target speed within the predetermined time. 2. The image forming apparatus according to claim 1, wherein error information indicating an abnormality in said power supply device is notified when said detection means detects that said power supply device is not in operation. When the optical scanning device is activated, the control means sets a control mode for controlling the optical scanning device to a rotation control mode, and changes the control mode to a laser control mode according to the state of the drive motor. 3. The image forming apparatus according to claim 2, wherein the optical scanning device is started by shifting in the order of , speed control mode, and phase control mode. rotation detection means for outputting a detection signal corresponding to the rotation speed of the rotating polygon mirror;
The drive motor has a rotor section having a plurality of magnetic poles and provided with the rotating polygon mirror,
The optical scanning device has signal generating means for detecting a change in magnetic flux generated by rotation of the drive motor and generating a rotation period signal,
In the rotation control mode, the control means drives the drive motor to drive the rotating polygon mirror, and when the first lock signal is output from the rotation detection means, the control mode is changed to the 4. The image forming apparatus according to claim 3 , wherein a transition is made from a rotation control mode to the laser control mode. The rotation detection means outputs the first lock signal if the rotation speed of the drive motor calculated based on the rotation cycle signal generated by the signal generation means is within a range of a first target rotation speed. 5. The image forming apparatus according to claim 4 , wherein: The optical scanning device has light beam detection means for detecting a light beam emitted from the light source and deflected by the rotating polygon mirror and outputting a detection signal,
3. The control means, in the laser control mode, shifts the control mode from the laser control mode to the speed control mode when the light beam detection means outputs the detection signal. 5. The image forming apparatus according to 5. In the speed control mode, the control means shifts the control mode from the speed control mode to the phase control mode when a second lock signal is output from the rotation detection means. The image forming apparatus according to claim 6 . The rotation detection means detects whether the rotation speed of the drive motor calculated based on the detection signal output by the light beam detection means is within a range of a second target rotation speed different from the first target rotation speed. 8. The image forming apparatus according to claim 7 , wherein the second lock signal is output. The control means controls the rotation of the drive motor so that the phase of the detection signal output from the light beam detection means and the phase of the reference clock signal for driving the drive motor match, and the phases match. a phase control unit that outputs a third lock signal when the
9. The image forming apparatus according to claim 8 , wherein in the phase control mode, when the third lock signal is output from the phase control section, an image forming operation is started. The notifying means is provided when the third lock signal is not output from the phase control section even after a first predetermined time has elapsed since the control mode for controlling the optical scanning device was set to the rotation control mode. wherein error information of the optical scanning device including information of the control mode is notified when the detecting means detects that a current is supplied from the power supply to the driving motor . 10. The image forming apparatus according to claim 9 . The notification means is adapted to prevent current from being supplied from the power supply to the drive motor when the third lock signal is not continuously output from the phase control unit for a second predetermined time during execution of the image forming operation. 10. The image forming apparatus according to claim 9 , wherein error information of the optical scanning device including the information of the phase control mode is notified when the detecting means detects that the light is being supplied. A display unit that displays the error information,
The error information to be displayed includes information on the optical scanning device in which the abnormality has occurred and the control mode;
12. The image forming apparatus according to claim 10 , wherein the controller displays the error information on the display unit. A management system comprising: a plurality of image forming apparatuses according to any one of claims 2 and 9 to 11 ; and a management apparatus connected to the plurality of image forming apparatuses via a network line. a system,
The image forming apparatus transmits the error information to the management apparatus,
A management system, wherein the management device has a display device for displaying information, analyzes the error information received from the plurality of image forming devices, and displays the error information on the display device.

Images