Patent Application
20190101843
The present invention relates to an image forming apparatus including an optical scanning device.
There has been known an image forming apparatus including an optical scanning device that forms an electrostatic latent image on a photosensitive member, by deflecting a light flux (a light beam) emitted from a light source such as a laser diode by a rotatable polygon mirror, and scanning a surface to be scanned of the photosensitive member. Image forming apparatuses of this type include a color image forming apparatus for forming a color image on a recording medium, and a monochrome image forming apparatus for forming a monochrome image on a recording medium. In general, the color image forming apparatus is configured to form an image by using toner of four colors of yellow, magenta, cyan, and black. As for color image forming apparatuses of recent years, a configuration having a photosensitive member and a development device for each color has been mainstream. Such color image forming apparatuses are further classified. Specifically, the color image forming apparatuses are classified into an image forming apparatus in which one optical scanning device corresponds to one photosensitive member, an image forming apparatus in which one optical scanning device corresponds to two photosensitive members, and an image forming apparatus in which one optical scanning device corresponds to four photosensitive members. As for the image forming apparatus in which one optical scanning device corresponds to one photosensitive member and the image forming apparatus in which one optical scanning device corresponds to two photosensitive members, a plurality of optical scanning devices are provided.
In an optical scanning device, a light beam output may attenuate or no light beam may be output due to an abnormality such as deterioration of a laser diode serving as a light source. This may cause a failure in an image to be formed on a recording medium. In such a situation, whether an abnormality has occurred in the optical scanning device may be determined by, for example, determining whether an output signal (hereinafter referred to as a beam detector (BD) signal) of a start position sensor (a beam detector) for deciding timing for starting irradiation of a light beam toward a photosensitive member is generated. The light beam emitted from the laser diode is incident on the start position sensor via a rotatable polygon mirror and various optical lenses included in the optical scanning device. Therefore, in a case where the BD signal is not output from the start position sensor, it is difficult to identify which one of the laser diode, the rotatable polygon mirror, and the start position sensor has an abnormality. For example, Japanese Patent Application Laid-Open No. 2008-040295 discusses an image forming apparatus for detecting a fault of an optical scanning device, by determining whether a value of a drive current of a laser diode is normal, and further by determining the presence or absence of output of a BD signal.
In the above-described conventional example, the fault is determined based on complex information by monitoring the drive current of the laser diode and the output of the BD signal. However, there is a case where the above-described image forming apparatus including the plurality of optical scanning devices has such a configuration that a control signal is common to the optical scanning devices, or power is supplied from the same power supply device. In a case where an abnormality occurs in the common control signal or the power supply device in such a configuration, a problem arises. Specifically, it is difficult to identify whether a fault is an abnormality of the optical scanning device or an abnormality of the common signal or the like, only by using the drive current of the laser diode and the presence or absence of the output of the BD signal.
Considering such a situation, the present invention is directed to accurately detecting a fault at the time of occurrence of an abnormality in an optical scanning device.
According to an aspect of the present invention, the present invention includes the following configuration.
An image forming apparatus includes a plurality of image forming units having a photosensitive member at which an image is to be formed, a plurality of optical scanning devices configured to expose the photosensitive member, a controller configured to control the plurality of optical scanning devices, and a power supply device configured to supply power to the optical scanning device, wherein the optical scanning device includes a motor and an output unit, the motor rotating a rotatable polygon mirror for deflecting a light beam to allow scanning of a surface of the photosensitive member by the light beam emitted from a light source for emitting the light beam, and the output unit outputting a rotation signal by detecting a rotation of the motor, wherein the controller includes a startup controller, a control unit, and a power supply path, the startup controller being provided for the optical scanning device and performing startup control of the optical scanning device based on output of a drive signal for driving the motor, the control unit controlling the startup controller, and the power supply path being provided to supply the optical scanning device with power generated by the power supply device, wherein the startup controller includes a counter for counting a clock signal, the counter having a counter value to be reset by the rotation signal output from the output unit, and wherein, in a case where the motor is not normally driven when the optical scanning device is started up, the control unit notifies an abnormality of the power supply device or the power supply path, based on a counter value of the counter acquired from the startup controller.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Exemplary embodiments of the present invention will be described in detail below with reference to the drawings.
An intermediate transfer belt 13 serving as an intermediate transfer member and having a long length is provided downstream from the registration roller pair 12 in the conveyance direction of the transfer sheet S (hereinafter may be simply referred to as the downstream side). The intermediate transfer belt 13 is stretched by a drive roller 13a, a secondary-transfer counter roller 13b, and a tension roller 13c, and set to have a substantially triangular shape in a cross-sectional view. The intermediate transfer belt 13 rotates in a clockwise direction in
Optical scanning devices 101, 102, 103, and 104 each serving as an exposure device are provided above the photosensitive drums 14, 15, 16, and 17, respectively, in
The image formation in the image forming apparatus illustrated in
While the intermediate transfer belt 13 rotates in the clockwise direction, the intermediate transfer belt 13 passes through a transfer portion between the photosensitive drum 14 and a transfer charger 90, and the toner image of yellow is thereby transferred onto the intermediate transfer belt 13. Next, the intermediate transfer belt 13 passes through a transfer portion between the photosensitive drum 15 and a transfer charger 91, and the toner image of magenta is thereby transferred onto the intermediate transfer belt 13. Subsequently, the intermediate transfer belt 13 passes through a transfer portion between the photosensitive drum 16 and a transfer charger 92, and the toner image of cyan is thereby transferred onto the intermediate transfer belt 13. Finally, the intermediate transfer belt 13 passes through a transfer portion between the photosensitive drum 17 and a transfer charger 93, and the toner image of black is thereby transferred onto the intermediate transfer belt 13. The transfer of the toner image of the color from each of the photosensitive drums 14 to 17 onto the intermediate transfer belt 13 is performed with a timing, and the toner images of yellow, magenta, cyan, and black are transferred onto the intermediate transfer belt 13 to be superimposed on one another.
Meanwhile, the transfer sheet S is sent to the registration roller pair 12 so that the skew state is corrected. The registration roller pair 12 start rotating, with a timing for allowing the position of the leading edge of the transfer sheet S to coincide with the toner images on the intermediate transfer belt 13. Next, the transfer sheet S is sent by the registration roller pair 12 to a transfer portion T2, which is an abutting portion between a secondary transfer roller 40 and the secondary-transfer counter roller 13b on the intermediate transfer belt 13. The color toner image is thereby transferred onto the transfer sheet S. Upon passing through the transfer portion T2, the transfer sheet S is sent to a fixing device 35 serving as a fixing unit. Subsequently, while the transfer sheet S passes through a nip portion formed of a fixing roller 35A and a pressing roller 35B in the fixing device 35, the toner image is heated by the fixing roller 35A and pressed by the pressing roller 35B, and the toner image is thereby fixed to the transfer sheet S. Upon passing through the fixing device 35, the transfer sheet S is sent to a discharging roller pair 37 by a conveyance roller pair 36, and further, discharged onto a discharge tray 38 provided outside the apparatus. The color image forming apparatus in
A controller 130 controls each of the above-described devices to perform the above-described image forming operation. A power supply device 150 generates a 5-V direct current (DC) to be supplied to a control system including the controller 130 and an optical scanning device controller 300 to be described below. The power supply device 150 also generates a 24-V DC to be supplied to a load of a driving system such as a motor. Further, an operation unit 140 is provided in an upper part of the image forming apparatus. The operation unit 140 has an input portion for inputting data and a display portion for displaying information. The optical scanning device controller 300 (hereinafter referred to as the controller 300) serving as a controller controls the optical scanning devices 101 to 104 (to be described in detail below).
The optical scanning device 101 has a phase-locked loop (PLL) circuit 201, a motor drive circuit 202, the scanner motor 203, a laser diode 206, a beam detector 207, a pulse width adjustment circuit 208, a frequency generator (FG) waveform shaping circuit 209, a selector 210, and a beam detector (BD) waveform shaping circuit 212. The PLL circuit 201, the motor drive circuit 202, the pulse width adjustment circuit 208, the FG waveform shaping circuit 209, the selector 210, and the BD waveform shaping circuit 212 may be formed in a single integrated circuit. Further, at least one of the PLL circuit 201, the motor drive circuit 202, the pulse width adjustment circuit 208, the FG waveform shaping circuit 209, the selector 210, and the BD waveform shaping circuit 212 may be built in a different integrated circuit, or all of these circuits may be built in different integrated circuits. A plurality of magnets 211 is attached to an inner circumferential surface of a rotor 203a of the scanner motor 203. A rotatable polygon mirror 204 for deflecting a laser beam emitted from the laser diode 206 serving as a light source is fixed to the rotor 203a. Furthermore, the scanner motor 203 has a Hall device 205 serving as an output unit for detecting a rotating state of the scanner motor 203. In the scanner motor 203, the rotor 203a rotates by feeding of an electric current to a coil 203b, and following the rotation, the rotatable polygon mirror 204 rotates. When the scanner motor 203 rotates, i.e., when the rotor 203a rotates, a magnetic flux around the Hall device 205 changes. Following the rotation of the rotor 203a (according to a rotation speed), the Hall device 205 converts the flux change around the Hall device 205 into an FG signal that is an electric signal, and outputs the FG signal.
The FG waveform shaping circuit 209 shapes the waveform of the FG signal output from the Hall device 205. The FG waveform shaping circuit 209 shapes the waveform to output the input FG signal of one pulse each time the scanner motor 203 makes one rotation, and then outputs the FG signal to the selector 210 and the ASIC 301. The beam detector 207 (hereinafter referred to as the BD 207) outputs a BD signal upon receiving a laser beam, which is deflected by the rotatable polygon mirror 204 after being emitted from the laser diode 206. The rotatable polygon mirror 204 has a plurality of reflection surfaces, and the BD signal is output according to the number of the reflection surfaces each time the scanner motor 203 makes one rotation. The pulse width adjustment circuit 208 adjusts the pulse width of the BD signal output from the BD 207 to have, for example, a duty ratio of 50%, and outputs the BD signal with the adjusted pulse width to the ASIC 301 and the BD waveform shaping circuit 212. The BD waveform shaping circuit 212 shapes the waveforms of the plurality of BD signals that are output each time the scanner motor 203 makes one rotation, such that a 1-pulse signal is to be output each time the scanner motor 203 makes one rotation. The BD waveform shaping circuit 212 then outputs the pulse signal to the selector 210.
The selector 210 outputs the FG signal input from the FG waveform shaping circuit 209 or the pulse signal input from the BD waveform shaping circuit 212, to the PLL circuit 201, according to a selection signal output from the ASIC 301. The PLL circuit 201 outputs a clock signal formed by synchronizing a reference clock signal input from the ASIC 301 with the phase of the signal output from the selector 210. The motor drive circuit 202 generates a drive signal based on the clock signal input from the PLL circuit 201 and thereby drives the scanner motor 203. This allows the scanner motor 203 to rotate the rotatable polygon mirror 204, and the surface of the photosensitive drum 14 is thereby scanned by the laser beam emitted from the laser diode 206. An electrostatic latent image can be thus formed.
The ASIC 301 receives the FG signal and the BD signal serving as a rotation signal from the optical scanning device 101, and outputs a reference clock signal and a selection signal to the optical scanning device 101. The selection signal specifies a signal to be output from the selector 210 to the PLL circuit 201. Further, the ASIC 301 has a counter to be incremented by an internal clock.
The 24-V DC generated in the power supply device 150 is supplied to each of the optical scanning devices 101 to 104 to drive the scanner motor 203. Specifically, a 24-V DC power supply voltage (indicated as common 24-V power supply in
From the CPU 305, control signals (Y) to (K) for ordering startup or startup-stop of the optical scanning devices 101 to 104 are output to the ASICs 301 to 304, respectively. From the ASICs 301 to 304, FG data (Y) to (K) to be described below are output to the CPU 305. In
Next, operation performed by the CPU 305 to control the optical scanning devices 101 to 104 via the ASICs 301 to 304 will be described. In a case where image formation is performed, the controller 130 instructs the controller 300 to start up the optical scanning devices 101 to 104, prior to the image formation. The CPU 305 of the controller 300 transmits control signals for ordering startup of the optical scanning devices 101 to 104 to the ASICs 301 to 304, according to a startup instruction from the controller 130. Upon receiving the control signals from the CPU 305, the ASICs 301 to 304 output the reference clock signal and the selection signal for ordering selection of the FG signal, to the optical scanning devices 101 to 104. In order to stop the driving of the scanner motors 203 by stopping the startup of the optical scanning devices 101 to 104, the CPU 305 transmits control signals for ordering startup-stop of the optical scanning devices 101 to 104 (driving stop of the scanner motor 203), to the ASICs 301 to 304. In the present exemplary embodiment, the startup-start and the startup-stop of the optical scanning devices 101 to 104 are controlled by output and output-stop of the reference clock signals.
In the optical scanning devices 101 to 104, startup of the scanner motors 203 is performed according to the control of the ASICs 301 to 304. The PLL circuit 201 generates a drive signal based on the FG signal output from the selector 210 and the reference clock signal input from the corresponding one of the ASICs 301 to 304. The generated drive signal is output to the motor drive circuit 202, and the motor drive circuit 202 performs rotation control for the scanner motor 203 according to the drive signal. The ASICs 301 to 304 each output, to the CPU 305, the FG data, which is measured in a predetermined sampling period (in the present exemplary embodiment, a period corresponding to one rotation of the scanner motor 203 is the sampling period) according to the FG signal output from the corresponding one of the optical scanning devices 101 to 104. The method for measuring the FG data according to the FG signal will be described below. Subsequently, based on the FG data output from the ASICs 301 to 304, the CPU 305 determines the presence or absence of an abnormal state of each of the optical scanning devices 101 to 104. When detecting the abnormal state, the CPU 305 notifies the controller 130 of the resultant.
Further, the ASICs 301 to 304 determine rotating states of the respective scanner motors 203, based on the FG signals output from the optical scanning devices 101 to 104. If the ASICs 301 to 304 each determine that the scanner motor 203 has reached a stable rotation state, the ASICs 301 to 304 each output a selection signal for ordering selection of the BD signal to the selector 210. The PLL circuits 201 of the optical scanning devices 101 to 104 thereby generate drive signals based on the BD signals output from the selectors 210 according to the selection signals and the reference clock signals input from the ASICs 301 to 304. The generated drive signal is output to the motor drive circuit 202, and the motor drive circuit 202 performs rotation control for the scanner motor 203 according to the drive signal. The CPU 305 determines a rotating state of each of the scanner motors 203, based on the BD signals output from the optical scanning devices 101 to 104 via the ASICs 301 to 304. When the CPU 305 determines that the scanner motors 203 of all the optical scanning devices 101 to 104 are stably rotating, the CPU 305 notifies the controller 130 of startup completion of the optical scanning devices 101 to 104, and the controller 130 starts the image formation.
Next, the method for measuring the FG data output from the ASICs 301 to 304 to the CPU 305 will be described.
First, counting operation of the FG counter will be described. The FG counter is provided inside each of the ASICs 301 to 304, and is incremented in response to input of a clock signal. In the present exemplary embodiment, the counter value becomes 0 when the FG counter is reset, and counting stops when the counter value becomes 999 that is a predetermined value. In response to input of a control signal from the CPU 305, the FG counter is reset and starts counting. Further, the FG counter is controlled to be reset in synchronization with a rising edge of the FG signal output from each of the optical scanning devices 101 to 104 and to start counting again. When the counter value becomes 999, the FG counter keeps holding the counter value (999) until the FG signal is input and the FG counter is reset at the rising edge of the FG signal, or the control signal is input from the CPU 305 to reset the FG counter. When the rising edge of the FG signal is input, the ASICs 301 to 304 each latch the counter value of the FG counter at that time. Alternatively, when the counter value of the FG counter becomes 999, the ASICs 301 to 304 each latch the counter value of 999 at that time. The ASICs 301 to 304 then each output the latched counter value of the FG counter to the CPU 305 as the FG data.
Next, the FG data to be input from each of the ASICs 301 to 304 to the CPU 305 will be described.
The graph in
As illustrated in
Next, a method for counting the SFG will be described.
Next, a control sequence performed by the CPU 305 to detect an abnormal state of each of the optical scanning devices 101 to 104 according to the FG data will be described.
In step S500, the CPU 305 resets a retry flag K indicating whether the current startup control of the scanner motor 203 is a first time (0) or a retry (1). In step S501, the CPU 305 transmits the control signals for ordering the startup control of the scanner motors 203 of the optical scanning devices 101 to 104 to the ASICs 301 to 304. Further, the CPU 305 sets 0 as a sampling count S indicating a sampling frequency of the FG data from each of the ASICs 301 to 304. The ASICs 301 to 304 having received the control signals from the CPU 305 output the reference clock signals to the respective optical scanning devices 101 to 104 and selection signals for instructing the PLL circuits 201 to output the FG signals, thereby starting the startup control of the scanner motors 203. In addition, the ASICs 301 to 304 each start the FG counter after the FG counter is reset, and thereby start counting by the FG counter to output the FG data to the CPU 305. In step S502, the CPU 305 acquires the FG data from each of the ASICs 301 to 304 and updates the sampling count S by adding 1. In step S503, the CPU 305 determines whether the sampling count S is 15. If the CPU 305 determines that the sampling count S is 15 (YES in step S503), the processing proceeds to step S504. If the CPU 305 determines that the sampling count S is not 15 (NO in step S503), the processing returns to step S502.
In step S504, the CPU 305 calculates the SFGtotal based on the FG data acquired from the ASICs 301 to 304 when the sampling count S is 15. In other words, the CPU 305 calculates how many FG data of 999 (the state where the scanner motor 203 is not rotating, and the FG signal is not output) are included in the FG data acquired when the sampling count S is 15. In step S505, the CPU 305 determines whether the value of the SFGtotal calculated in step S504 is 4, i.e., whether the scanner motor 203 is not normally started up in each of the optical scanning devices 101 to 104. If the CPU 305 determines that the value of the SFGtotal is 4 (YES in step S505), the processing proceeds to step S506. If the CPU 305 determines that the value of the SFGtotal is not 4 (NO in step S505), the processing proceeds to step S508. In step S506, based on the retry flag K, the CPU 305 determines whether the retry is already performed. If the CPU 305 determines that the retry flag K is 1, i.e., the retry is already performed (YES in step S506), the processing proceeds to step S507. If the CPU 305 determines that the retry flag K is not 1, i.e., the retry has not been performed (NO in step S506), the processing proceeds to step S517. In step S517, the CPU 305 transmits the control signals for ordering the startup-stop of the optical scanning devices 101 to 104 to the ASICs 301 to 304 to forcefully stop the driving of the scanner motors 203. Further, the CPU 305 sets 1 as the retry flag K and the processing returns to step S501. The ASICs 301 to 304 having received the control signals from the CPU 305 stop outputting the reference clock signals to the optical scanning devices 101 to 104, respectively, to stop the startup of the scanner motors 203, and each also stop the counting by the FG counter.
In step S507, the CPU 305 notifies the controller 130 of an abnormal state 1 where the scanner motors 203 of all the optical scanning devices 101 to 104 are not started up. The CPU 305 then transmits the control signals for ordering the startup-stop of the scanner motors 203 of the optical scanning devices 101 to 104 to the ASICs 301 to 304, and the processing ends. To stop the startup of the scanner motors 203, the ASICs 301 to 304 having received the control signals from the CPU 305 stop outputting the reference clock signals to the optical scanning devices 101 to 104, respectively, and each also stop the counting by the FG counter.
In step S508, the CPU 305 determines whether the value of the SFGtotal calculated in step S504 is less than 4 and more than 1, i.e., whether the scanner motor 203 of each of two or three optical scanning devices among the optical scanning devices 101 to 104 is not normally started up. If the CPU 305 determines that the value of the SFGtotal is less than 4 and more than 1 (YES in step S508), the processing proceeds to step S509. If the CPU 305 determines that the value of the SFGtotal is not less than 4 or not more than 1 (the SFGtotal is 0 or 1) (NO in step S508), the processing proceeds to step S511. In step S509, based on the retry flag K, the CPU 305 determines whether the retry is already performed. If the CPU 305 determines that the retry flag K is 1, i.e., the retry is already performed (YES in step S509), the processing proceeds to step S510. If the CPU 305 determines that the retry flag K is not 1, i.e., the retry has not been performed (NO in step S509), the processing proceeds to step 5517.
In step S510, the CPU 305 notifies the controller 130 of an abnormal state 2 where the scanner motor 203 of each of two or three optical scanning devices among the optical scanning devices 101 to 104 is not started up. The CPU 305 then transmits the control signals for ordering the startup-stop of the scanner motors 203 of the optical scanning devices 101 to 104 to the ASICs 301 to 304, and the processing ends. To stop the startup of the scanner motors 203, the ASICs 301 to 304 having received the control signals from the CPU 305 stop outputting the reference clock signals to the optical scanning devices 101 to 104, respectively, and each also stop the counting by the FG counter.
In step S511, the CPU 305 determines whether the value of the SFGtotal calculated in step S504 is 1, i.e., whether the scanner motor 203 of one optical scanning device among the optical scanning devices 101 to 104 is not normally started up. If the CPU 305 determines that the value of the SFGtotal is 1 (YES in step S511), the processing proceeds to step S512. If the CPU 305 determines that the value of the SFGtotal is not 1 (NO in step S511), i.e. the SFGtotal is 0, the processing proceeds to step S514. In step S512, the CPU 305 determines whether the retry is already performed. If the CPU 305 determines that the retry flag K is 1, i.e., the retry is already performed (YES in step S512), the processing proceeds to step S513. If the CPU 305 determines that the retry flag K is not 1, i.e., the retry has not been performed (NO in step S512), the processing proceeds to step S517.
In step S513, the CPU 305 notifies the controller 130 of an abnormal state 3 where the scanner motor 203 of one optical scanning device among the optical scanning devices 101 to 104 is not started up. The CPU 305 then transmits the control signals for ordering the startup-stop of the scanner motors 203 of the optical scanning devices 101 to 104 to the ASICs 301 to 304, and the processing ends. To stop the startup of the scanner motors 203, the ASICs 301 to 304 having received the control signals from the CPU 305 stop outputting the reference clock signals to the optical scanning devices 101 to 104, respectively, and each also stop the counting by the FG counter.
In step S514, based on the FG data acquired from the ASICs 301 to 304 when the sampling count S is 15, the CPU 305 determines whether the stable rotation state where each of the FG data is larger than 95 and less than 105 is established, i.e., whether the scanner motor 203 is stably rotating. In a case where the CPU 305 determines that all the FG data acquired from the ASICs 301 to 304 are larger than 95 and less than 105 (YES in step S514), the CPU 305 determines that the scanner motor 203 of each of the optical scanning devices 101 to 104 is stably rotating, and the processing ends. On the other hand, in a case where the CPU 305 determines that the FG data not being larger than 95 and less than 105 is included in the FG data acquired from the ASICs 301 to 304, the CPU 305 determines that the scanner motor 203 not stably rotating is present (NO in step S514), and the processing proceeds to step S515. In step S515, the CPU 305 determines whether the retry is already performed. If the CPU 305 determines that the retry flag K is 1, i.e., the retry is already performed (YES in step S515), the processing proceeds to step S516. If the CPU 305 determines that the retry flag K is not 1, i.e., the retry has not been performed (NO in step S515), the processing proceeds to step S517.
In step S516, the CPU 305 notifies the controller 130 of an abnormal state 4 where the optical scanning device having the scanner motor 203 not stably rotating is included in the optical scanning devices 101 to 104. The CPU 305 then transmits the control signals for ordering the startup-stop of the scanner motors 203 of the optical scanning devices 101 to 104 to the ASICs 301 to 304, and the processing ends. To stop the startup of the scanner motors 203, the ASICs 301 to 304 having received the control signals from the CPU 305 stop outputting the reference clock signals to the optical scanning devices 101 to 104, respectively, and each also stop the counting by the FG counter.
As described above, in a case where the scanner motor of the optical scanning device is not normally started up, the presence or absence of an abnormality of the power supply path for the optical scanning device is determined, based on the configuration of the power supply path for supplying power to each of the optical scanning devices, and the startup status of the scanner motor of each of the optical scanning devices. Thereby, in particular, in a case where a plurality of optical scanning devices is not normally started up, an abnormality factor can be accurately identified. In addition, in the present exemplary embodiment, whether the scanner motor is normally rotating is detected by resetting the counter based on the FG signal output from each of the optical scanning devices to detect the rotating state of the scanner motor of each of the optical scanning devices. Whether the optical scanning device is normally started up can be detected with such a simple configuration and thus, a cost reduction is achieved. As described above, according to the present exemplary embodiment, a fault at the time of occurrence of an abnormality in the optical scanning device can be accurately detected.
The above-described exemplary embodiment is an exemplary embodiment applied to the optical scanning device having the 1-in-1 configuration in which one optical scanning device exposes one photosensitive drum. Among optical scanning devices, there is an optical scanning device having a 2-in-1 configuration in which one optical scanning device exposes two photosensitive drums. The above-described exemplary embodiment is applicable to the optical scanning device having the 2-in-1 configuration.
As for the optical scanning device having the 2-in-1 configuration, one optical scanning device can expose two photosensitive drums, i.e., can form an electrostatic latent image on each of the two photosensitive drums.
As for an abnormality of the power supply device 150 or the power supply path 311 on the control circuit board of the controller 300 in the case of adopting the 2-in-1 configuration, the following is conceivable. In other words, in a case where the SFGtotal is 2, conceivably, the controller 300 has such an abnormality that the 24 V power supply voltage is not output from the power supply device 150, or the power supply path 311 on the control circuit board of the controller 300 is disconnected, as in the case where the SFGtotal in the 1-in-1 configuration is 4. Further, in a case where the SFGtotal is 1, there may be conceivably an abnormality of the controller 300 such as disconnection between a branch point for the optical scanning device (Y, M) of the power supply path 311 on the control circuit board of the controller 300 and the connector of the optical scanning device (C, K).
As described above, according to the other exemplary embodiment, a fault at the time of occurrence of an abnormality in the optical scanning device can be accurately detected.
According to the exemplary embodiments of the present invention, a fault at the time of occurrence of an abnormality in the optical scanning device can be accurately detected.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2017-189561, filed Sep. 29, 2017, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-189561 | Sep 2017 | JP | national |
