JP2016038491A - High-voltage power supply unit and image formation apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-voltage power supply unit capable of detecting abnormality even in a state of no high-voltage output, and an image formation apparatus using the same.SOLUTION: A high-voltage power supply unit 200 includes a control substrate 202 and a high-voltage substrate 204, and is connected using a cable harness 206. A voltage from a voltage source Vcc1 is applied to high voltage transformer circuits 220, 224 through the cable harness and a fuse 210. Further, a voltage from a constant voltage source is applied to bases of transistors T1, T2 after being stepped down through the cable harness and fuse. If all the transistors turn on with an external load not in operation, a low-level error signal is input to respective ports 102a, 102b of a CPU. When the cable harness is disconnected or when the fuse is blown, on the other hand, all the transistors turn off and a high-level error signal is input to the respective ports of the CPU.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a high-voltage power supply device and an image forming apparatus using the same, and more particularly to a high-voltage power supply device and an image forming apparatus using the high-voltage power supply device for detecting an abnormality in an external load connected thereto.

  An example of a conventional high-voltage power supply device of this type is disclosed in Patent Document 1. In the high voltage fault detection apparatus of Patent Document 1, a current flowing through the drum ground of the photosensitive drum is detected, and a fault in the high voltage generation circuit is detected based on the detection result.

JP 2003-208062 A

  However, the conventional high voltage fault detection device detects whether or not the high voltage generating circuit is faulty only when high voltage output is being performed. For this reason, for example, when a cable harness for connecting the control unit and the high-voltage power supply unit is disconnected or a fuse on the power supply line of the high-voltage power supply unit is blown, However, the operation of the image forming apparatus cannot be stopped until after printing is started. As a result, image damage such as blank paper printing and mechanical damage due to rising of the carrier have occurred. However, blank printing means that when printing is executed, the recording medium is output as blank paper without being printed on a recording medium such as paper.

  Therefore, a main object of the present invention is to provide a novel high-voltage power supply device and an image forming apparatus using the same.

  Another object of the present invention is to provide a high voltage power supply apparatus and an image forming apparatus using the same, which can detect an abnormality even when high voltage output is not being performed.

  A first invention is a high-voltage power supply device used in an image forming apparatus. The high-voltage power supply device includes an application unit, a first determination unit, and a notification unit. The applying means applies a high voltage obtained by boosting the voltage from the constant voltage source to the external load. The first judging means judges whether or not the voltage from the constant voltage source is applied to the applying means. The notifying means notifies the abnormality when the first determining means determines that the voltage from the constant voltage source is not applied to the applying means.

  According to the first invention, since it is determined whether or not the voltage from the constant voltage source is applied to the applying means for applying a high voltage to the external load, the high-voltage power supply apparatus even in a state where no high-voltage output is being performed An abnormality in can be detected. Accordingly, it is possible to prevent the occurrence of image damage such as blank paper printing and the occurrence of mechanical damage due to the carrier rising.

  A second invention is dependent on the first invention, and the first determination means includes a voltage detection means. The voltage detection means detects a voltage applied from the constant voltage source to the application means. The first determining means determines whether or not the voltage from the constant voltage source is applied to the applying means according to the detection result of the voltage detecting means.

  According to the second invention, since only the voltage from the constant voltage source is detected, it is easy to determine whether or not the voltage from the constant voltage source is applied to the applying means.

  The third invention is dependent on the first or second invention, and the first determination means is set when the main power of the image forming apparatus is turned on or when the image forming apparatus is restarted. It is determined whether or not the voltage from the voltage source is applied to the applying means.

  According to the third aspect of the invention, it is possible to detect an abnormality in the high-voltage power supply when high-voltage output is not being performed, such as when the main power supply of the image forming apparatus is turned on or restarted.

  A fourth invention is dependent on any one of the first to third inventions, and the high-voltage power supply device includes a plurality of applying means. The plurality of applying units correspond to each of the plurality of external loads, and apply a high voltage to the corresponding external loads. The first determination unit determines whether or not a voltage from a constant voltage source is applied to each of the plurality of application units. The notifying means individually notifies the abnormality on the primary side of the plurality of applying means according to the determination result of the first determining means.

  According to the fourth invention, since the abnormality on the primary side of each applying means is individually notified, it is possible to notify the location where the abnormality has occurred. Therefore, it is possible to appropriately know the cause of the abnormality, and it is easy to work during maintenance.

  A fifth invention is dependent on any one of the first to fourth inventions, and the high-voltage power supply device further includes a second determination means. The second determining means determines whether a high voltage is applied to the external load by the applying means. The notifying means determines when the first determining means determines that the voltage from the constant voltage source is not input to the applying means and when the second determining means determines that no high voltage is applied to the external load. Anomalies with different contents are notified at different times. For example, when the first judging means judges that the voltage from the constant voltage source is not input to the applying means, the cable harness is disconnected or the fuse is blown on the primary side of the applying means. Is notified. On the other hand, when it is determined by the second determination means that a high voltage is not applied to the external load, the fuse is blown, or an abnormality in the external load connected to the application means has occurred. Is notified.

  According to the fifth aspect, since not only the first determination unit but also the second determination unit is provided, the notification content can be changed according to the determination result. Therefore, it is possible to appropriately know the cause of the abnormality, and it is easy to work during maintenance.

  A sixth invention is an image forming apparatus using the high-voltage power supply device according to any one of the first to fifth inventions.

  In the sixth aspect of the invention, it is possible to detect an abnormality in the high-voltage power supply device even when high-voltage output is not being performed.

  According to the present invention, since it is determined whether or not the voltage from the constant voltage source is applied to the application means for applying a high voltage to the external load, an abnormality in the high-voltage power supply apparatus can be achieved even in a state where high-voltage output is not being performed. Can be detected. Accordingly, it is possible to prevent the occurrence of image damage such as blank paper printing and the occurrence of mechanical damage due to the carrier rising.

FIG. 1 is a schematic sectional view showing the internal structure of the image forming apparatus according to the first embodiment of the present invention. FIG. 2 is an illustrative view schematically showing a configuration of an image forming unit provided in the image forming apparatus shown in FIG. FIG. 3 is a block diagram showing an example of the electrical configuration of the image forming apparatus shown in FIG. FIG. 4 is a circuit diagram showing the high-voltage power supply device of the first embodiment. FIG. 5 is a graph showing an example of a voltage applied to an external load connected to the high-voltage power supply device shown in FIG. 4 and a control range of a current flowing through the external load. FIG. 6 is a circuit diagram showing an example of the high-voltage transformer circuit shown in FIG. FIG. 7 is a flowchart showing an example of the high voltage error detection processing of the CPU shown in FIG. FIG. 8 is a circuit diagram showing the high-voltage power supply device of the second embodiment. FIG. 9 is a flowchart showing a part of the high voltage error detection processing of the CPU of the second embodiment.

[First embodiment]
Referring to FIG. 1, an image forming apparatus 10 according to an embodiment of the present invention is a multifunction peripheral (MFP) having a copying function, a printer function, a scanner function, a facsimile function, and the like, and a color printing mode. Alternatively, it operates in a monochrome printing mode to form a multicolor or single color image on a sheet (recording medium). As will be described in detail later, the image forming apparatus 10 includes an intermediate transfer type image forming unit 30, and uses an intermediate transfer belt (primary transfer belt) 54 that is stretched around a plurality of rollers 56 and 58. Thus, the toner image formed on the photosensitive drum 36 is transferred to a sheet.

  First, the basic configuration of the image forming apparatus 10 will be schematically described. As shown in FIGS. 1 and 2, the image forming apparatus 10 includes an apparatus main body 12 including an image forming unit 30 and the like, and an image reading apparatus 14 disposed above the apparatus main body 12.

  The image reading device 14 includes a document placing table 16 formed of a transparent material. A document pressing cover 18 is attached above the document placing table 16 through a hinge or the like so as to be freely opened and closed. The document pressing cover 18 is provided with an ADF (automatic document feeder) 24 that automatically feeds the documents placed on the document placing tray 20 one by one to the image reading position 22. An operation unit 28 (see FIG. 3) that accepts an input operation by the user is provided on the front side of the document table 16. The operation unit 28 includes a display device 28a such as an LCD, a touch panel provided in association with the display device 28a (typically on the display surface of the display device 28a), hardware operation buttons, and an image forming apparatus. A main switch for turning on and off 10 apparatus power supplies (main power supplies) is included.

  Further, the image reading device 14 is provided with an image reading unit 26 including a light source, a plurality of mirrors, an imaging lens, a line sensor, and the like. The image reading unit 26 exposes the document surface with a light source, and guides the reflected light reflected from the document surface to the imaging lens by a plurality of mirrors. Then, the reflected light is imaged on the light receiving element of the line sensor by the imaging lens. The line sensor detects the luminance and chromaticity of the reflected light imaged on the light receiving element, and generates image data based on the image on the document surface. As the line sensor, a charge coupled device (CCD), a contact image sensor (CIS), or the like is used.

  The apparatus main body 12 is provided with a control unit including the CPU 102 and memories (106, 108, 110) (see FIG. 3), the image forming unit 30, and the like. The control unit transmits a control signal to each part of the image forming apparatus 10 according to an input operation to the operation unit 28 by the user, and causes the image forming apparatus 10 to execute various operations.

  The image forming unit 30 includes an exposure unit 32, a developing unit 34, a photosensitive drum 36, a cleaner unit 38, a charger 40, an intermediate transfer belt unit 42, a secondary transfer roller 44, a fixing unit 46, and the like, and a paper feed tray 48. Alternatively, an image is formed on the paper conveyed from the manual paper feed tray 50, and the image-formed paper is discharged to the discharge tray 52. As image data for forming an image on a sheet, image data read by the image reading unit 26, image data transmitted from an external computer, or the like is used.

  Here, the image data handled in the image forming apparatus 10 corresponds to four color images of black (BK), magenta (M), cyan (C), and yellow (Y). For this reason, each of the developing device 34, the photosensitive drum 36, the cleaner unit 38, and the charging device 40 is provided so as to form four types of latent images corresponding to the respective colors, thereby providing four image stations. Composed. The four image stations are arranged in a line along the running direction (circumferential movement direction) of the surface of the intermediate transfer belt 54, and are located downstream from the intermediate transfer belt 54 in the running direction, that is, close to the secondary transfer roller 44. From the side, they are arranged in the order of black, magenta, cyan and yellow. However, the arrangement order of the colors can be changed as appropriate.

  Note that the subscripts BK, M, C, and Y given to the reference numerals are for indicating elements provided for any color, and the subscripts BK, M, C, and Y are respectively , Black, magenta, cyan and yellow. For example, reference numeral 36BK in FIG. 2 indicates that the photosensitive drum is for black (for BK). Further, in the description of each part, when it is not particularly necessary to distinguish which color is used, the subscripts BK, M, C, and Y are omitted, and the description will be made comprehensively.

  The photosensitive drum 36 is an image carrier in which a photosensitive layer is formed on the surface of a cylindrical substrate having conductivity. The charger 40 is a roller type or brush type member that charges the surface of the photosensitive drum 36 to a predetermined potential. Further, the exposure unit 32 is configured as a laser scanning unit (LSU) including a laser emitting portion and a reflection mirror, and exposes the surface of the charged photosensitive drum 36 so that an electrostatic latent image corresponding to image data is obtained. An image is formed on the surface of the photosensitive drum 36. The developing device 34 visualizes the electrostatic latent image formed on the surface of the photosensitive drum 36 with four color toners. The cleaner unit 38 removes toner remaining on the surface of the photosensitive drum 36 after development and image transfer, and conveys the toner to a waste toner box (not shown).

  The intermediate transfer belt unit 42 includes an intermediate transfer belt 54, a drive roller 56, a driven roller 58, four intermediate transfer rollers 60, and the like, and is disposed above the photosensitive drum 36.

  The intermediate transfer belt 54 is a flexible endless belt, and is composed of polyimide (PI), polyamide (PA), polyvinylidene fluoride (PVDF), or the like, which is appropriately mixed with a conductive material such as carbon black. It is formed of resin or rubber. The intermediate transfer belt 54 is stretched by a plurality of rollers such as a driving roller 56 and a driven roller 58, and is provided so that an outer peripheral surface thereof is in contact with each photosensitive drum 36. As the drive roller 56 is driven to rotate, it moves around in a predetermined direction (counterclockwise in FIGS. 1 and 2).

  The intermediate transfer roller (primary transfer roller) 60 is a roller-like member in which an elastic layer is laminated on the outer peripheral surface of the cored bar. The core metal of the intermediate transfer roller 60 is formed of a metal such as stainless steel or aluminum, and the elastic layer is made of ethylene-propylene rubber (EPDM), foamed EPDM, foamed urethane, or the like appropriately mixed with a conductive material such as carbon black. Formed by rubber. However, as the intermediate transfer roller 60, a metal roller that does not have an elastic layer on the outer peripheral surface can be used from the viewpoint of cost reduction and downsizing of the apparatus.

  The intermediate transfer roller 60 is provided at a position facing each of the photosensitive drums 36 with the intermediate transfer belt 54 interposed therebetween, and is brought into pressure contact with the inner peripheral surface of the intermediate transfer belt 54 to rotate as the intermediate transfer belt 54 rotates. To do.

  At the time of image formation, a voltage (primary transfer voltage) having a polarity opposite to the charging polarity of the toner constituting the toner image formed on the surface of the photosensitive drum 36 is applied to the intermediate transfer roller 60. As a result, a current corresponding to the applied voltage flows through the intermediate transfer roller 60 (primary transfer current is supplied).

  When the primary transfer current is supplied to the intermediate transfer roller 60, the primary transfer current flows through the transfer current supply position to the intermediate transfer belt 54, and is transferred between the photosensitive drum 36 and the intermediate transfer belt 54 at the primary transfer position. An electric field is formed. The toner image formed on the photosensitive drum 36 is transferred (primary transfer) to the outer peripheral surface of the intermediate transfer belt 54 by the action of the transfer electric field formed at the primary transfer position.

  For example, when forming a color image, each color toner image formed on each photosensitive drum 36 is sequentially transferred onto the intermediate transfer belt 54 and a multicolor toner image is formed on the intermediate transfer belt 54. Is done. On the other hand, when forming a monochrome image, an electrostatic latent image and a toner image are formed only on the black photosensitive drum 36BK, and only the black toner image is transferred to the outer peripheral surface of the intermediate transfer belt 54. .

  A secondary transfer roller 44 is disposed in the vicinity of the driving roller 56, and a voltage (secondary transfer voltage) is applied to the secondary transfer roller 44. Therefore, due to the action of the transfer electric field formed by the secondary transfer roller 44 to which a voltage is applied, the sheet of the intermediate transfer belt 54 passes through the transfer nip region between the intermediate transfer belt 54 and the transfer roller 44. The toner image formed on the outer peripheral surface is transferred (secondary transfer) to the sheet.

  The fixing unit 46 includes a heat roller 62 and a pressure roller 64 and is disposed above the secondary transfer roller 44. The heat roller 62 is set to have a predetermined fixing temperature. When the paper passes through the nip area between the heat roller 62 and the pressure roller 64, the toner image transferred to the paper is melted. The toner image is heat-fixed on the sheet by mixing and pressing.

  In the apparatus main body 12, the paper placed on the paper feed cassette 48 or the manual paper feed cassette 50 is sent to the paper discharge tray 52 via the registration roller 68, the secondary transfer roller 44 and the fixing unit 46. Therefore, a first sheet conveyance path S1 is formed. Further, when performing duplex printing on the sheet, the sheet after the one-side printing is finished and passed through the fixing unit 46 is transferred to the first sheet conveyance path S1 on the upstream side in the sheet conveyance direction of the secondary transfer roller 44. A second paper transport path S2 for returning is formed. A plurality of transport rollers 66 for transporting paper are appropriately provided in the first paper transport path S1 and the second paper transport path S2.

  When single-sided printing is performed in the apparatus main body 12, the sheets placed on the sheet feeding cassette 48 or the manual sheet feeding cassette 50 are guided to the first sheet conveying path S 1 one by one by the pickup roller 70, and are conveyed by the conveying roller 66. It is conveyed to the registration roller 68. Then, the registration roller 68 conveys the toner image onto the paper at a timing when the leading edge of the paper and the leading edge of the image information on the intermediate transfer belt 54 are aligned. Thereafter, when the toner passes through the fixing unit 46, the unfixed toner on the paper is melted and fixed by heat, and the paper is discharged onto the paper discharge tray 52 through a conveyance roller (paper discharge roller) 66.

  On the other hand, when performing double-sided printing, when the trailing edge of the paper that has passed through the fixing unit 46 after single-sided printing has reached the paper discharge roller 66 near the paper discharge tray 52, the paper discharge roller 66 is reversed. By rotating, the sheet runs backward and is guided to the second sheet conveyance path S2. The paper guided to the second paper transport path S2 is transported through the second paper transport path S2 by the transport roller 66, and is guided to the first paper transport path S1 on the upstream side of the registration roller 68 in the paper transport direction. At this time, the front and back sides of the sheet are reversed, and thereafter, the sheet passes through the secondary transfer roller 44 and the fixing unit 46, whereby printing is performed on the back side of the sheet.

  FIG. 3 is a block diagram illustrating an example of an electrical configuration of the image forming apparatus 10. The image forming apparatus 10 includes a CPU 102. The CPU 102 is connected to the ROM 106, the RAM 108, the HDD 110, the communication interface (communication I / F) 112, and the power control unit 114 via the internal bus 104, and the above-described image reading unit 26, operation unit 28, and image formation. Connected to the unit 30, the exposure unit 32, the fixing unit 46, and the like.

  The CPU 102 (first determination unit, second determination unit, notification unit) is also called a processor or a microcomputer, and comprehensively controls the operation of each part of the image forming apparatus 10 such as the image reading unit 26 and the image forming unit 30. To do.

  The ROM 106 stores a program (Boot program) for starting a main processing program (operating system) of the image forming apparatus 10. The RAM 108 is used as a work memory or buffer memory for the CPU 102. The HDD 110 is a main storage device of the image forming apparatus 10, and appropriately stores a control program and data for the CPU 102 to control the operation of each part of the image forming apparatus 10. However, another nonvolatile memory such as a flash memory may be provided instead of the HDD 110 or together with the HDD 110.

  The communication I / F 112 is an interface for communicating with a computer. The power supply control unit 114 steps down and rectifies an AC voltage from a commercial power supply, and applies a power supply (voltage) to each part of the image forming apparatus 10 including the high-voltage power supply device 200 (see FIG. 4) under the instruction of the CPU 102. To do.

  FIG. 4 is a circuit diagram showing the high-voltage power supply device 200 of the first embodiment. Here, a description will be given of the high voltage power supply apparatus 200 that applies power (high voltage output) to the developing device 34BK and the intermediate transfer roller 60BK. However, similar high voltage power supply devices are provided for the other developing devices (34Y, 34C, 34M) and intermediate transfer rollers (60Y, 60C, 60M).

  As shown in FIG. 4, the high-voltage power supply device 200 includes a control board 202 on which a control unit including a CPU 102 and the like is mounted, and a high-voltage board 204 that applies a high voltage to an external load. Electrical connection is made using a cable harness 206.

  Although omitted in FIG. 4, circuit components such as the CPU 102, the ROM 106, the RAM 108, and the power supply control unit 114 described above are mounted on the control board 202. The HDD 110 and the communication I / F 112 may be mounted on the control board 202 or may be connected to the CPU 102 so as to be communicable, for example, mounted on a board different from the control board 202.

  As shown in FIG. 4, the control board 202 is supplied with a constant voltage source Vcc1 (for example, 24 V), a constant voltage source Vcc2 (for example, 5 V) to which a voltage is applied from the power supply control unit 114 of the image forming apparatus 10, and A constant voltage source Vcc3 (for example, 5V) is provided. The constant voltage source Vcc1 is connected to the high voltage transformer circuit 220 (application unit) and the high voltage transformer circuit 224 (application unit) via the cable harness 206 and the fuse 210 of the high voltage board 204. That is, the fuse 210 is inserted (mounted) on the primary power supply line of the high-voltage transformer circuit 220 and the high-voltage transformer circuit 224.

  In the control board 202, one end of the resistor R1 mounted on the control board 202 is connected to the port 102a of the CPU 102, and the transistor T1 mounted on the high-voltage board 204 is connected via the cable harness 206. The collector is connected. A constant voltage source Vcc2 is connected to the other end of the resistor R1. Therefore, the voltage from the constant voltage source Vcc2 is applied to the port 202a and the collector of the transistor T1 via the resistor R1.

  Further, one end of the resistor R2 mounted on the control board 202 is connected to the port 102b of the CPU 102, and the collector of the transistor T2 mounted on the high voltage board 204 is connected via the cable harness 206. A constant voltage source Vcc3 is connected to the other end of the resistor R2. Therefore, the voltage from the constant voltage source Vcc3 is applied to the port 102b and the collector of the transistor T2 via the resistor R2.

  One end of the resistor R11 mounted on the high-voltage board 204 is connected to the connection point between the fuse 210 and the high-voltage transformer circuit 220, and the other end of the resistor R11 is one end of the resistor R13, the output end of the comparator 222a, and the comparator. It is connected to the output terminal of 222b. The other end of the resistor R13 is connected to the base of the transistor T1, and the emitter of the transistor T1 is grounded. The output terminal of the high voltage transformer circuit 220 is connected to the terminal 230. An external load (here, the developing device 34BK) is connected to the terminal 230. For example, the external load is equivalently represented by a parallel circuit of a resistor and a capacitor.

  Further, the voltage (detection voltage) obtained by converting the current output from the high-voltage transformer circuit 220 to the external load is detected as one input terminal of the comparator 222a (in this first embodiment, the positive input terminal) and the comparator 222b. On the other hand, a connection line for inputting to the input terminal (minus input terminal in the first embodiment) is connected from the high voltage transformer circuit 220 to the comparator 222a and the comparator 222b. However, the detection voltage corresponds to a voltage obtained by stepping down a high voltage applied to the external load.

  A reference voltage E1 is applied to the other input terminal of the comparator 222a (in this first embodiment, a negative input terminal). However, when the external load connected to the high voltage transformer circuit 220 is normal, the reference voltage E1 is set to a voltage value lower than the detected voltage taken out (feedback) from the high voltage transformer circuit 220. The same applies to a reference voltage E3 input to a comparator 226a described later.

  The reference voltage E2 is applied to the other input terminal of the comparator 222b (plus input terminal in the first embodiment). However, the reference voltage E2 is set to a voltage value higher than the detection voltage fed back from the high voltage transformer circuit 220 when the external load connected to the high voltage transformer circuit 220 is normal. The same applies to a reference voltage E4 input to a comparator 226b described later.

  In the first embodiment, a comparator 222a is provided to detect a state in which the external load is short (short detection), and an open state in which the external load is not connected is detected (open detection). In order to do so, a comparator 222b is provided.

  For example, as shown in FIG. 5, the control range for properly operating the external load (here, the developing device 34BK) is determined by the range of the voltage V applied to the external load and the range of the current I flowing through the external load. Is done. In the example shown in FIG. 5, the voltage V is controlled between 1 (kv) and 3 (kv), and the current I is controlled between 2 (μA) and 30 (μA). However, constant current control is performed in the first embodiment.

  In the open state (open state) in which no external load is connected, the voltage V applied to the external load is very high, and the current I flowing through the external load is very large in constant current control. On the other hand, in a state where the external load is short-circuited (short-circuit state), the current I flowing through the external load is very small, so the applied voltage V is also low. Therefore, in the first embodiment, the threshold for open detection is set to 4 (kV), and the threshold for short detection is set to 0.5 (kV). The reference voltage E1 and the reference voltage E2 are set so as to have such a threshold value.

  These are the same for the comparator 226a and the comparator 226b, which will be described later, but the control range and threshold value may differ depending on the external load.

  As will be described later, in the first embodiment, the threshold value is set as described above in order to explain the case where a positive bias voltage is applied. However, in the case where a negative bias voltage is applied, as described above. The reference voltage E1 and the reference voltage E2 are negative voltage values. In this case, the polarities of the input terminals of the comparator 222a and the comparator 222b are reversed, and the voltage values of the reference voltage E1 and the reference voltage E2 are the absolute values of the voltage value and the voltage value of the detection voltage. It is set so as to be a magnitude relationship. The same applies to the comparator 226a and the comparator 226b described later.

  One end of the resistor R12 mounted on the high-voltage board 204 is connected to a connection point between the fuse 210 and the high-voltage transformer circuit 224, and the other end of the resistor R12 is one end of the resistor R14, the output end of the comparator 226a, and It is connected to the output terminal of the comparator 226b. The other end of the resistor R14 is connected to the base of the transistor T2, and the emitter of the transistor T2 is grounded. The output terminal of the high voltage transformer circuit 224 is connected to the terminal 232. An external load (here, intermediate transfer roller 60BK) is connected to the terminal 232. Further, a connection line for inputting the detected voltage obtained by converting the current output from the high voltage transformer circuit 224 to the external load to the positive input terminal of the comparator 226a and the negative input terminal of the comparator 226b is a high voltage transformer circuit 224. To the comparator 226a and the comparator 226b. A reference voltage E3 is applied to the negative input terminal of the comparator 226a. The reference voltage E4 is applied to the positive input terminal of the comparator 222b.

  When the main power supply of the image forming apparatus 10 is turned on, power (voltage) is supplied from the power control unit 114 to the high voltage power supply device 200 under the instruction of the CPU 102. As a result, voltages are applied to the constant voltage source Vcc1, the constant voltage source Vcc2, and the constant voltage source Vcc3.

  When the control board 202 and the high voltage board 204 are connected using the cable harness 206 and the attached fuse 210 is not blown, that is, when the primary side of the high voltage transformer circuit 220 and the high voltage iron lance circuit 224 is normal. The voltage from the constant voltage source Vcc1 is applied to the high voltage transformer circuit 220 and the high voltage transformer circuit 224 via the fuse 210.

  At this time, the voltage from the constant voltage source Vcc1 via the fuse 210 is applied to the base of the transistor T1 via the resistor R11 and the resistor R13. Similarly, the voltage from the constant voltage source Vcc1 via the fuse 210 is applied to the base of the transistor T2 via the resistor R12 and the resistor R14. Therefore, the transistors T1 and T2 are turned on. Therefore, a current due to the voltage of the constant voltage source Vcc2 flows to the ground via the collector and emitter of the transistor T1, and similarly, a current due to the voltage of the constant voltage source Vcc1 flows to the ground via the collector and emitter of the transistor T2. Therefore, the voltage input to the port 102a and the voltage (error signal) input to the port 102b are at a low level.

  Here, each port (102a, 102b) of the CPU 102 shown in FIG. 4 has an abnormality in the external load connected to the high voltage power supply device 200 and / or the high voltage power supply device 200 (hereinafter sometimes referred to as “high voltage error”). It is provided for inputting a signal (hereinafter referred to as an “error signal”) for determining whether or not it has occurred. When no high voltage error has occurred, a low level error signal is input to the corresponding port (102a, 102b). On the other hand, when a high voltage error has occurred, a high level error signal is input to the corresponding port (102a, 102b).

  Further, when the cable harness 206 is not connected, when the fuse 210 is blown (cut or blown), or when the fuse 210 is not attached, that is, the high-voltage transformer circuit 220 and the high-voltage cage When an abnormality occurs on the primary side of the lance circuit 224, the voltage from the constant voltage source Vcc1 is not applied to the high voltage transformer circuit 220 and the high voltage transformer circuit 224.

  At this time, the voltage from the constant voltage source Vcc1 is not applied to the base of the transistor T1 and the base of the transistor T2. In such a case, the voltage from the constant voltage source Vcc2 is applied to the port 102a via the resistor R1, and the voltage from the constant voltage source Vcc3 is applied to the port 102b via the resistor R2. That is, when an abnormality occurs on the primary side of the high voltage transformer circuit 220 and the high voltage transformer circuit 224, a high level error signal is input to the port 102a and the port 102b.

  As described above, when the external load is not operated as when the main power supply of the image forming apparatus 10 is turned on, the resistor R11, the resistor R13, and the transistor T1 cause the constant voltage source Vcc1 to the high-voltage transformer circuit 220. The applied voltage is detected (voltage detection means). Similarly, in a state where the external load is not operated, the voltage applied from the constant voltage source Vcc1 to the high voltage transformer circuit 224 is detected by the resistor R12, the resistor R14, and the transistor T2 (voltage detection means).

  However, the present invention is not limited to the case where the main power supply of the image forming apparatus 10 is turned on, and also when the image forming apparatus 10 performs a return operation (when restarted) or simply does not execute printing. It is the same.

  The CPU 102 determines whether the voltage from the constant voltage source Vcc1 is applied to the high voltage transformer circuit 220 and the high voltage transformer circuit 224 according to the level of the error signal, and according to the determination result, the high voltage transformer circuit 220 and the high voltage transformer circuit 224. It detects whether the primary side of the high voltage transformer circuit 224 is normal or abnormal.

  Therefore, the cable harness 206 is disconnected and the fuse 210 is blown without operating the developing unit (here 34BK) or the intermediate transfer roller (here 60BK), that is, without outputting high voltage. It is possible to detect an abnormality (high voltage error) of the high voltage power supply apparatus 200 such as that the fuse 210 is not installed or the fuse 210 is not installed. That is, an error can be notified without executing printing.

  Therefore, it is possible to prevent the occurrence of image quality defects such as blank paper printing and the occurrence of mechanical damage due to the rising carrier. However, blank printing means that when printing is executed, the recording medium is output as blank paper without being printed on a recording medium such as paper.

  For example, when an abnormality is detected such that the cable harness 206 is disconnected or the fuse 210 is blown or not installed, a message notifying the abnormality is displayed on the display device 28a included in the operation unit 28. Or a sound for notifying abnormality is output from a speaker (not shown), or both of them are executed. The same applies to the case where an abnormality is detected.

  However, when an external load is operated as in a short state or an open state, an abnormality (high voltage error) may be detected based on the output from the high voltage transformer circuit 220 or the high voltage transformer circuit 224. In such a case, the fuse 210 is blown or an abnormality has occurred in the external load connected to the high-voltage transformer circuit 220. That is, at the time of high voltage output, an abnormality may occur not only on the primary side of the high voltage transformer circuit (220, 224) but also on the secondary side. Therefore, in the first embodiment, different messages are displayed when the external load is not operated (not outputting high voltage) and when the external load is operated (outputting high voltage). (Notification). However, the CPU 102 determines that high voltage output is not performed when printing is not performed, and determines that high voltage output is performed when printing is performed.

  When the external load connected to the high-voltage transformer circuit 220 is operating normally, the outputs of the comparator 222a and the comparator 222b are both high. This is because the detection voltage extracted from the high-voltage transformer circuit 220 is within a range determined by the reference voltage E1 and the reference voltage E2. For this reason, in addition to the voltage from the constant voltage source Vcc1, the high level voltage from the comparator 222a and the comparator 222b is applied to the base of the transistor T1, and the transistor T1 is kept on. Therefore, a low level error signal is input to the port 102a.

  On the other hand, when the high-voltage transformer circuit 220 and / or the external load connected to the high-voltage transformer circuit 220 are not operating normally, the circuit is in an open state or a short state, and the output from the comparator 222a or the comparator 222b is at a low level. It becomes. For this reason, the voltage applied to the base of the transistor T1 is reduced. Therefore, the transistor T1 is turned off, and a high-level error signal is input to the port 102a.

  When the external load connected to the high voltage transformer circuit 224 is operating normally, the outputs of the comparator 226a and the comparator 226b are both at a high level, as in the high voltage transformer circuit 220. This is because the detection voltage extracted from the high voltage transformer circuit 224 is within a range determined by the reference voltage E3 and the reference voltage E4. For this reason, in addition to the voltage from the constant voltage source Vcc1, the high level voltage from the comparator 226a and the comparator 226b is applied to the base of the transistor T2, and the transistor T2 is kept on. Therefore, a low level error signal is input to the port 102b.

  On the other hand, when the external load connected to the high-voltage transformer circuit 224 or when it is not operating normally, it is in an open state or a short state, and the output from the comparator 226a or the comparator 226b becomes a low level. For this reason, the voltage applied to the base of the transistor T2 is reduced. Accordingly, the transistor T2 is turned off, and a high-level error signal is input to the port 102b.

  In this way, the CPU 102, the constant voltage source Vcc2, the resistor R1, the resistor R11, the resistor R13, the transistor T1, the comparator 222a, and the comparator 222b are used to detect an abnormality on the primary side and the secondary side of the high-voltage transformer circuit 220. A circuit (high voltage error detection circuit) 250 is configured.

  Similarly, the CPU 102, the constant voltage source Vcc3, the resistor R2, the resistor R12, the resistor R14, the transistor T2, the comparator 226a, and the comparator 226b are used to detect abnormalities on the primary side and the secondary side of the high voltage transformer circuit 224. An error detection circuit 252 is configured.

  FIG. 6 is an example of a circuit diagram of the high-voltage transformer circuit 220 shown in FIG. Hereinafter, the high-voltage transformer circuit 220 will be described, but the same applies to the high-voltage transformer circuit 224. As shown in FIG. 6, the high-voltage transformer circuit 220 includes a terminal 260, and one end of a resistor R <b> 21 is connected to the terminal 260. The other end of the resistor R21 is connected to a constant voltage power supply Vcc4 (for example, 5V) via a resistor R22, and is connected to a plus input end of the operational amplifier 262 via a resistor R23.

  A constant voltage source Vcc5 (for example, 5 V) is connected to the negative input terminal of the operational amplifier 262 via a resistor R24. One end of the resistor R25 is connected to a connection point between the operational amplifier 262 and the resistor R24, and the other end of the resistor R25 is grounded.

  The output terminal of the operational amplifier 262 is connected to the base of the transistor T11 and is connected to the negative input terminal of the operational amplifier 262 via the resistor R26 and the capacitor C1. The collector of the transistor T11 is connected to a constant voltage source Vcc6 (for example, 24V) via a resistor R27. The emitter of the transistor T11 is connected to the base of the transistor T12.

  The constant voltage source Vcc6 is connected to one end of the primary side coil L1 of the high-voltage transformer 264, and the other end of the coil L1 is connected to the collector of the transistor T12. The emitter of the transistor T12 is grounded.

  The base of the transistor T2 is connected to one end of another coil L2 on the primary side of the high-voltage transformer 264 via the resistor R28 and the capacitor C2, and the other end of the coil L2 is grounded.

  The anode of the diode D1 is connected to one end of the secondary side coil L3 of the high voltage transformer 264, and the cathode of the diode D2 is connected to the other end of the coil L3. The cathode of the diode D1 is connected to the terminal 230 via the resistor R29. A connection point between the diode D1 and the resistor R29 is connected to one end of the capacitor C3 and one end of the resistor R30.

  The other end of the capacitor C3 is connected to the anode of the diode D2 and grounded via the capacitor C4. The connection point between the capacitor C3 and the capacitor C4 is connected to each of the resistors 21 to R23. The other end of the resistor R30 is connected to the capacitor C4 via the resistor R31. The connection point between the resistor R30 and the resistor R31 is connected to the plus input terminal of the comparator 222a and the minus input terminal of the comparator 222b shown in FIG.

  In such a high voltage transformer circuit 220, a voltage of a predetermined voltage value (for example, 5 V) is applied from the voltage control unit 114 to the constant voltage source Vcc4 and the constant voltage source Vcc5 under the instruction of the CPU 102. Further, a voltage from a constant voltage source Vcc1 provided on the control board 202 is applied to the constant voltage power supply Vcc6.

The terminal 260, the constant current control signal from the CPU 102 (e.g., 1V to 5V) is inputted, the operational amplifier 262, the current _{I 3} flowing through the external load is controlled (constant current control) so that the constant current. However, the current _{I 3} is the current _{I 1} flowing through the resistor R22 by the constant voltage of the constant voltage source Vcc 4, a current obtained by adding the current _{I 2} flowing through the resistor R21 by the constant current control signal. Current _{I 3} is resistor R31, the resistor R30, through the external load through the resistor R29 and the terminal 230. Further, the voltage value of the constant current control signal is set according to the current value of the current I ₃ to be constant current controlled.

Since part of the current I ₃ also flows to the operational amplifier 262 side, the current flowing through the external load is actually a little smaller than the current I ₃ . However, since the current flowing to the operational amplifier 262 side is very small, the current flowing to the external load is set as the current I ₃ .

  Further, the operational amplifier 262 is subjected to negative feedback control. Specifically, the operational amplifier 262 is driven such that a voltage having the same voltage value as that applied to the negative input terminal (for example, 2.5 V) is applied to the positive input terminal.

  The transistor T11 is turned on / off by the output (drive signal) of the operational amplifier 262. When the transistor T11 is turned on, a current (base current) flows through the base of the transistor T12, and the transistor T12 is also turned on. Therefore, the high voltage transformer 264 is turned on. For this reason, a voltage is applied to the coil L1, and at the same time, a voltage is generated in the coil L2. The voltage generated in the coil L2 causes the transistor T12 to further conduct, and becomes a positive feedback voltage, so that the transistor T12 is rapidly turned on. As a result, a voltage is further applied to the coil L1 of the high-voltage transformer 264.

  Since the voltage of the coil L3 is applied to the diode D1 and the diode D2 in reverse, no current flows through the coil L3. For this reason, the current flowing through the coil L1 is only the exciting current of the high-voltage transformer 264. When the base current cannot maintain the saturation of the transistor T12, the transistor T12 deviates from the saturation, and a voltage (hereinafter referred to as “Vce”) applied between the collector and the emitter of the transistor T12 increases.

  When the voltage Vce increases and the voltage of the coil L1 of the high-voltage transformer 264 decreases, the voltage of the coil L2 also decreases, and the voltage Vce further increases. Since this change is positively fed back, the transistor T12 is rapidly turned from on to off.

However, since the magnetic field generated in the high-voltage transformer 264 is kept the same even when the transistor T12 is turned off, a current flows through the coil L3 so as to maintain the same energy as the current flowing through the coil L1, and the diode D1 and the diode D2 Is conducted. When the diode D1 and the diode D2 are turned on, the energy stored in the high voltage transformer 264 is output. That is, the on / off the transistors T11 and transistor T12 so as to maintain the current I ₃ constant is controlled, a high voltage is outputted (applied) to an external load.

The voltage across the resistor R31 by the current I ₃ flowing through the external load (the detection voltage) is applied to the positive input terminal and the comparator negative input of 222b of the comparator 222a shown in FIG. However, the detection voltage corresponds to a voltage applied to the resistor R31 when a high voltage applied to the external load is divided by the resistor R29, the resistor R30, and the resistor R31.

  FIG. 7 is a flowchart showing an example of the high voltage error detection process of the CPU 102 shown in FIG. Although illustration is omitted, as described above, the HDD 108 (or ROM 106) stores a program (high voltage error detection program) for high voltage error detection processing. For example, after the main power supply of the image forming apparatus 10 is turned on and the operating system is started, this high-voltage error detection program is expanded in the RAM 104 and executed. In addition, after detecting the high voltage error, the high voltage error detection program is executed after the image forming apparatus 10 is restored (after being restarted).

  As shown in FIG. 7, when the high-voltage error detection process is started, the CPU 102 determines whether or not all error signals are at a low level in step S1. That is, the CPU 102 determines whether all error signals input to the ports (102a and 102b, etc.) are at a low level.

  If “YES” in the step S1, that is, if all error signals are at a low level, it is determined that the high-voltage power supply device 200 and the external load connected thereto are normal, and the process returns to the step S1 as it is. On the other hand, if “NO” in the step S1, that is, if at least one error signal is at a high level, it is determined whether or not all the error signals are in a high level in a step S3.

  If “NO” in step S3, that is, if some of all the error signals are at a high level, in step S5, they are connected to the high-voltage transformer circuit (220, 224) of the system for that part. Notifying that an external load abnormality has occurred, the high-pressure error detection process is terminated. That is, in step S5, for example, the CPU 102 displays a message indicating that an abnormality has occurred on the secondary side of the high-voltage transformer circuit (220, 224) on the display device 28a. Further, as described above, the CPU 102 may output a sound for notifying that an abnormality has occurred from the speaker as well as displaying a message. The same applies to the case of notifying abnormality. However, the system means an electric circuit including a high voltage transformer circuit (220, 224) that outputs a high voltage to one external load and a high voltage error detection circuit (250, 252) for the high voltage transformer circuit (220, 224). means.

  In the first embodiment, since one fuse 210 is attached to a plurality of (two) systems, if “NO” is determined in step S3, that is, a part of the error signal is high. When the level is reached, the image forming apparatus 10 is printing, and an abnormality has occurred on the secondary side of the high-voltage transformer circuit 200 or the high-voltage transformer circuit 224.

  On the other hand, if “YES” in the step S3, that is, if all the error signals are at a high level, it is determined whether or not printing is being performed in a step S7. However, when the main power source of the image forming apparatus 10 is turned on or when the image forming apparatus 10 is restarted, since the image forming apparatus 10 performs warming up, printing is not performed, and step S7 is performed. Becomes “NO”.

  If “NO” in the step S7, that is, if printing is not being performed, it is determined that an abnormality has occurred on the primary side of the high voltage transformer circuit (220, 224), and whether the cable harness 206 is disconnected in the step S9. The fuse 210 is informed that the fuse 210 is blown or not installed, and the high voltage error detection process is terminated.

  On the other hand, if “YES” in the step S 7, that is, if printing is being performed, the fuse 210 is blown in the step S 11, or the entire system is connected to the high voltage transformer circuit (220, 224). The abnormality of the external load is notified, and the high voltage error detection process is terminated.

  According to the first embodiment, on the primary side of the high voltage transformer circuit (220, 224), it is determined whether or not the voltage from the constant voltage power supply Vcc1 is applied via the cable harness 206 and the fuse 210. Even if the external load on the secondary side of the circuit (220, 224) is not operated, the abnormality on the primary side of the high-voltage transformer circuit (220, 224) can be detected only by turning on the main power supply. Therefore, it is possible to prevent the occurrence of unnecessary printing such as blank paper printing and the occurrence of mechanical damage due to carrier fogging.

  Further, in this first embodiment, it is possible to detect whether or not an abnormality has occurred on the primary side of the high voltage transformer circuit (220, 224) even when printing is not being performed (high voltage output is not being performed). Messages with different contents can be notified (displayed) when the printer is printing and when the printer is not printing (when outputting high voltage and when not outputting high voltage). That is, a message corresponding to the cause of the abnormality can be appropriately displayed. Therefore, it is easy to work during maintenance.

In the first embodiment, two systems of electric circuits for applying power to the developing device 34BK and the intermediate transfer roller 60BK are configured on the high-voltage board 204. However, the electric circuit may be one system or three systems or more. You may make it provide.
[Second Embodiment]
The image forming apparatus 10 of the second embodiment is the same as the first embodiment except that the fuse (210, 212) is inserted (attached) to the primary side of each high-voltage transformer circuit (220, 224) in the high-voltage power supply device 200. Since it is the same as the image forming apparatus 10 of the embodiment, different contents will be described, and overlapping contents will be omitted or briefly described.

  FIG. 8 shows a circuit diagram of the high-voltage power supply device 200 of the second embodiment. As can be seen from FIG. 8, in the high voltage power supply device 200 of the second embodiment, the power supply line of the high voltage transformer circuit 224 is connected to the constant voltage power supply Vcc1 through the fuse 212. One end of the resistor R12 is connected to a connection point between the fuse 212 and the high-voltage transformer circuit 224. The rest is the same as the high-voltage power supply apparatus 200 of the first embodiment.

  In the second embodiment, a fuse 210 is inserted on the primary side of the high voltage transformer circuit 220 and a fuse 212 is inserted on the primary side of the high voltage transformer circuit 224. Therefore, in the state where high voltage output is not performed, such as when the main power is turned on or restarted, if some error signals become high level, it corresponds to the ports (102a, 102b) where the error signal is high level. It is determined that the fuses (210, 212) inserted on the primary side of the high-voltage transformer circuits (220, 224) of some systems are blown. Therefore, the CPU 102 can identify the system and notify that the fuse (210, 212) inserted on the primary side of the high-voltage transformer circuit (220, 224) of the system is blown.

  Further, in a state where high voltage output is being performed as in printing, when some error signals become high level, fuses (210, 212) are blown in some of the systems, or It can be notified that an abnormality has occurred in the external load connected to the high-voltage transformer circuit (220, 224).

  The specific high-voltage error detection process is the same as the high-voltage error detection process described with reference to FIG. 7 in the first embodiment except that some processes are different as shown in FIG. Briefly described, steps S21, S23 and S25 are executed in place of the step S5 of the high voltage error detection process shown in FIG.

  In the second embodiment, since fuses (210, 212) are mounted on the primary side of the high-voltage transformer circuit (220, 224) in each system, if “NO” in step S3, it is determined whether printing is in progress. It is necessary to judge.

  As described in the first embodiment, if some of the plurality of error signals are high level in step S3, “NO” is determined. As shown in FIG. 9, whether printing is in progress in step S21. Judging.

  If “NO” in the step S21, that is, if printing is not in progress, in step S23, it is notified that the fuses (210, 212) of a part of the system whose error signal is high level are blown. Then, the high pressure error detection process is terminated.

  On the other hand, if “YES” in the step S21, that is, if printing is being performed, a fuse is blown in a part of the system in which the error signal is at a high level in the step S25, or a high-voltage transformer circuit The fact that an abnormality of the external load connected to (220, 224) has occurred is notified, and the high voltage error detection process is terminated.

  However, in the second embodiment, in step S11, the CPU 102 causes the fuse (210, 212) to melt or an abnormality in the external load connected to the high voltage transformer circuit (220, 224) occurs in all systems. Notify that you are doing.

According to the second embodiment, since the fuse (210, 212) is mounted on the primary side of each high-voltage transformer circuit (220, 224), the fusing of the fuse (210, 212) can be known for each system. . Therefore, when the main power supply is turned on or restarted, the fuse (210, 212) can be notified of the fusing of the fuse (210, 212) while being distinguished.
[Third embodiment]
In the image forming apparatus 10 of the third embodiment, the high voltage power supply device 200 is used for other external loads such as the exposure unit 32, the charger 40, the secondary transfer roller 44, and the front transfer unit. The same as in the first embodiment.

  However, although the front transfer unit is omitted in FIGS. 1 and 2, it is a corona discharger and is arranged downstream of the intermediate transfer roller 60, and charges the same polarity as the toner are intermediately transferred prior to the secondary transfer. The toner image developed on the belt 54 is applied to the toner image.

  In the third embodiment, a high-voltage power supply device for external load other than the high-voltage power supply device 200 shown in the first embodiment may be provided. The high-voltage power supply device shown in the first embodiment. At 200, other external load systems (high voltage transformer circuit and high voltage error detection circuit) may be added.

  Further, in this third embodiment, as shown in the second embodiment, in each system, a fuse (210, 212) is mounted on the primary side of the high-voltage transformer circuit (220, 224). Good.

  However, the high voltage (bias voltage) output from the high voltage transformer circuit (220, 224) is set to plus or minus depending on the external load. In the case of outputting a positive high voltage, the high voltage transformer circuit (220, 224) may be configured as shown in FIG. 6 of the first embodiment.

  On the other hand, in the case of outputting a negative high voltage, for example, in FIG. 6, the directions of the diode D1 and the diode D2 may be reversed. In such a case, the constants of the resistor R21, the resistor R22, and the resistors R29 to R31 are changed, and the positive input terminal and the negative input terminal of the operational amplifier 262 are reversed. Specifically, the connection point between the resistor R24 and the resistor R25 is connected to the plus input terminal of the operational amplifier 262, and the resistor R23 is connected to the minus input terminal. In such a case, the plus and minus input ends of the comparators 222a, 222b, 226a and 226b shown in FIG. 4 are reversed.

  According to the third embodiment, the high-voltage power supply device 200 can be used for various external loads to which a high voltage is applied.

  It should be noted that the specific numerical values shown in the above-described embodiments are examples, and can be appropriately changed according to the actual apparatus.

  Further, the above-described embodiment is merely an example and should not be limited. The scope of the present invention is indicated by each claim in the scope of claims after taking into account the description of the detailed description of the invention, and all modifications within the meaning and scope equivalent to the wording described therein are included. Including.

DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus 12 ... Apparatus main body 14 ... Image reading part 30 ... Image forming part 36 ... Photoconductor drum (image carrier)
54 ... Intermediate transfer belt (transfer belt)
60 ... Intermediate transfer roller (transfer roller)
102 ... CPU
106… ROM
108 ... RAM
110 ... HDD
DESCRIPTION OF SYMBOLS 114 ... Voltage control part 200 ... High voltage power supply device 202 ... Control board 204 ... High voltage board 206 ... Cable harness 250,252 ... High voltage error detection circuit

Claims (6)

A high-voltage power supply device used in an image forming apparatus,
Applying means for applying a high voltage obtained by boosting a voltage from a constant voltage source to an external load;
First determination means for determining whether a voltage from the constant voltage source is applied to the application means;
A high-voltage power supply apparatus comprising a notifying means for notifying an abnormality when it is determined by the first determining means that a voltage from the constant voltage source is not applied to the applying means.   The first determination unit includes a voltage detection unit that detects a voltage input from the constant voltage source to the application unit, and a voltage from the constant voltage source is applied to the application unit according to a detection result of the voltage detection unit. The high-voltage power supply device according to claim 1, wherein the high-voltage power supply device determines whether or not   The first determination unit is configured to apply a voltage from the constant voltage source to the application unit when a main power source of the image forming apparatus is turned on or when the image forming apparatus is restarted. The high-voltage power supply device according to claim 1, wherein the high-voltage power supply device determines whether or not there is any. A plurality of application means corresponding to each of the plurality of external loads, and further applying a high voltage to the corresponding external load,
The first determining means determines whether a voltage from the constant voltage source is applied to each of the plurality of applying means,
4. The high-voltage power supply device according to claim 1, wherein the notifying unit individually notifies abnormality on a primary side of the plurality of applying units according to a determination result of the first determining unit. A second determining means for determining whether or not the high voltage is applied to the external load by the applying means;
The notifying means applies the high voltage to the external load when the first judging means judges that the voltage from the constant voltage source is not applied to the applying means, and the second judging means applies the high voltage to the external load. The high-voltage power supply device according to any one of claims 1 to 4, wherein an abnormality of different contents is notified when it is determined that the operation has not been performed.   An image forming apparatus using the high-voltage power supply device according to claim 1.

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