JP2012013829A - Power source device, electrical equipment, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid storage of wrong content of an abnormal state by use of an inexpensive configuration.SOLUTION: The power source device includes: a storage section; an AC load; a switching section 65 for switching between the on and off states of AC power supplied to the AC load; a first transformation section 62 for converting AC power into DC power of first level; a second transformation section 63 for converting the DC power into DC power of second level; a zero-cross signal output section 64 for outputting a zero cross signal in response to a zero cross point of the AC power; a drive control section 42 operated by the DC power of the second level and causing the switching section 65 to switch between the on and off states in response to the zero cross signal; and an abnormal state detecting section 43 operated by the DC power of the second level and storing the content of an abnormal state of DC load operated by the DC power or the AC load in the storage section. The abnormal state detecting section 43 does not allow the storage section to store the content of the abnormal state during the time from the point in time that the zero cross signal has stopped to the point in time that the DC power supplied from the second transformation section 63 becomes less than the second level.

Description

  The present invention relates to a technique for detecting an abnormal state of a power source in an image forming apparatus such as a printer or an electric device that operates with power supplied from an AC power source, such as a refrigerator.

  Conventionally, in an electric device that operates with AC power supplied from a commercial power source such as an image forming apparatus such as a printer, a personal computer, a TV, or a refrigerator, AC power is converted into DC power of a predetermined level, A power supply device that supplies the predetermined level of DC power is provided to each functional operation unit such as each drive unit inside the electrical apparatus or a control unit that controls the drive unit.

  Such an electrical device is generally provided with an abnormality detection circuit that detects that an abnormality has occurred in the operation of each functional operation unit, and the content of the abnormality detected by the abnormality detection circuit is stored in a nonvolatile memory or It is configured to be stored in a storage medium such as an HDD.

  However, when an abnormality occurs in the power supply device, such as when the plug connected to the commercial power outlet is disconnected during the operation of the drive unit, the abnormality detection circuit detects the occurrence of the abnormality in the power supply device. It is detected that the drive unit has stopped operating due to the power supply from the power supply device being cut off and the drive unit itself has no abnormality. There is a possibility that the contents of an erroneous abnormality that is assumed to have been stopped due to an abnormality have been stored.

  Therefore, for example, in Patent Document 1 and Patent Document 2 below, a power supply monitoring device (power supply voltage measurement unit) that constantly monitors the voltage of a commercial power supply that is generally provided in an electric device is used. A technique is described that determines whether or not an abnormality has occurred in a predetermined portion (fixing heater heating control system) in accordance with a change in voltage being monitored by the (power supply voltage measuring unit).

  That is, in the techniques described in Patent Document 1 and Patent Document 2, when an abnormality occurs in the power supply device as described above, the power supply voltage being monitored by the power supply monitoring device (power supply voltage measuring unit) indicates zero. Thus, it is possible to detect that the supply of power from the power supply device has been cut off. Therefore, as described above, when the operation of the drive unit is stopped due to the interruption of the power supply from the power supply device, the content of the erroneous abnormality that the drive unit has failed and the operation has been stopped. Was able to avoid being memorized.

JP 2007-111182 A JP-A-2005-202219

  However, in the techniques described in Patent Document 1 and Patent Document 2, a signal line is provided to output a control signal indicating the power supply voltage being monitored by the power supply monitoring device (power supply voltage measurement unit) to the abnormality detection circuit. It was necessary to connect the signal line and the abnormality detection circuit. In other words, there is room for improvement in terms of cost in configuring an abnormality detection circuit that can avoid erroneously detecting that an abnormality has occurred in each functional operation unit when a power supply abnormality occurs. there were.

  Therefore, the present invention has been made in view of such circumstances, and an object of the present invention is to provide an inexpensive power supply device, electrical apparatus, and image forming apparatus that can avoid storing erroneous contents of an abnormality. And

The invention according to claim 1 is a storage unit;
A switching unit that switches on and off the AC power supplied to an AC load operated by AC power supplied from an AC power source;
A first transformer that converts AC power supplied from the AC power source into predetermined first level DC power;
A second transformer for converting DC power output from the first transformer into a predetermined second-level DC power different from the first level;
A zero cross signal output unit that outputs a zero cross signal in response to a zero cross point of the AC power supplied from the AC power supply;
A drive control unit that operates by direct current power supplied from the second transformer, and controls the switching unit to switch on and off in response to the zero-cross signal;
A first DC load that operates with DC power supplied from the second transformer, a first DC load that operates with DC power supplied from the first transformer, and a second that operates with DC power supplied from the second transformer. An abnormality detection unit that detects at least one abnormality of the DC load or the AC load and stores the content of the abnormality in the storage unit;
With
When the zero-cross signal is stopped, the abnormality detection unit is configured to perform a description of the abnormality from the time when the zero-crossing signal is stopped until the DC power supplied from the second transformer unit drops below the second level. Is a power supply device that does not store the information in the storage unit.

  In a conventional power supply device, for example, when AC power supplied from an AC power source is cut off, such as when a plug connected to a commercial power outlet is disconnected, the first DC load, the second DC load, or the AC load As the operation continues, AC power, power supplied from the first transformer or the second transformer is consumed, and power of a predetermined level is supplied from the first transformer or the second transformer. Disappear.

  Then, when the operation of the first DC load, the second DC load, or the AC load is stopped because the predetermined level of power is not supplied, the first DC load, the second DC load, or the AC Control that stores the content of the erroneous abnormality that is assumed to have been stopped due to the occurrence of an abnormality in the first DC load, the second DC load, or the AC load even though no abnormality has occurred in the load itself. Do.

  However, in this invention, when the zero cross signal output from the zero cross signal output unit stops due to the interruption of the AC power supplied from the AC power source, the abnormality detection unit stops the second transformer from the time of the stop. The content of the erroneous abnormality is not stored in the storage unit until the DC power supplied from the voltage drops below the second level.

  For this reason, at the time when the time from when the zero cross signal stops by the abnormality detection unit until the DC power supplied from the second transformer falls below the second level has already passed from the second transformer. Since the second-level DC power is not supplied, the abnormality detection unit stops operating, and the abnormality detection unit is prevented from storing the content of the erroneous abnormality in the storage unit.

  In addition, the zero cross signal output from the zero cross signal output unit used in the abnormality detection unit is configured to be used for the control of the switching unit in the drive control unit, for example, whether or not the AC power is cut off. It is not necessary to newly provide a functional operation unit for detecting that AC power is cut off, such as providing a detection unit for detecting whether or not and providing a new signal line connected to the detection unit. For this reason, the abnormality detection unit can be configured at low cost.

Moreover, invention of Claim 2 is the power supply device of Claim 1, the said alternating current load, the said 1st load, or the said 2nd load,
It is an electric equipment provided with.

  According to the present invention, the effect of the first aspect of the invention can be achieved in the electrical apparatus.

Further, the invention according to claim 3 is a power supply device according to claim 1,
A fixing heater for heating with AC power supplied from the AC power source as the AC load;
An image forming apparatus comprising:
The switching unit switches on / off of AC power supplied to the fixing heater,
When the zero-cross signal is stopped, the abnormality detection unit performs a period from the time when the zero-crossing signal is stopped until the DC power supplied from the second power transformation unit drops below the second level. The image forming apparatus does not store the content of the abnormality in the storage unit.

  In this invention, when the AC power is not supplied, such as when the plug connected to the outlet of the commercial power supply is disconnected, there is no abnormality in the fixing heater even though there is no abnormality in the fixing heater itself. It is avoided to memorize the contents of an erroneous abnormality that has occurred and stopped operation.

  Further, the zero cross signal output from the zero cross signal output unit used in the abnormality detection unit is configured to be used for controlling the switching unit for switching on / off of the AC power supplied to the fixing heater. For example, a detection unit that detects whether or not AC power is cut off and a new signal line that is connected to the detection unit is provided. Therefore, the abnormality detection unit can be configured at low cost.

  According to the present invention, it is possible to provide an inexpensive power supply device, electrical apparatus, and image forming apparatus that can avoid storing erroneous details of an abnormality.

1 is a schematic diagram showing a copying machine as an example of an electric apparatus according to the present invention. 1 is a block diagram illustrating an example of an electrical configuration of a copying machine. The block diagram which shows an example of a structure of the function operation | movement part relevant to a power supply device. The timing chart which shows an example of the control signal which a drive control part controls ON / OFF of a zero cross signal and a switching part. The flowchart which shows an example of the operation | movement which an abnormality detection part records the content of abnormality.

  A copying machine as an example of an electrical apparatus according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic view showing a copying machine 1 as an example of an electric apparatus according to the present invention. The copying machine 1 includes a main unit 200, a sheet post-processing unit 300 disposed on the left side of the main unit 200, an operation unit 400 for a user to input various operation commands and the like, and an upper part of the main unit 200. The document reading unit 500 is provided, and the document feeding unit 800 is provided above the document reading unit 500.

  The operation unit 400 includes a touch panel 401, a start key 402, a numeric keypad 403, and the like.

  The touch panel 401 displays various operation screens including a screen for setting an enlargement / reduction ratio, and displays various operation buttons and the like for the user to input various operation commands. The start key 402 is used for the user to input a print execution command and the like, and the ten key 403 is used for inputting the number of copies to be printed.

  The document feeding unit 800 includes a document placement unit 801, a document discharge unit 802, a paper feed roller 803, a document transport unit 804, and the like, and the document reading unit 500 includes a scanner 501 and the like.

  The paper feed roller 803 feeds out the original set on the original placement unit 801, and the original transport unit 804 transports the fed originals one by one on the scanner 501. The scanner 501 sequentially reads the conveyed document, and the read document is discharged to the document discharge unit 802.

  The main body 200 includes a plurality of paper feed cassettes 201, a plurality of paper feed rollers 202, a transfer roller 203, an intermediate transfer body roller 204, a photosensitive drum 205, an exposure device 206, and development for each color of yellow, magenta, cyan, and black. Devices 207Y, 207M, 207C, and 207K, a fixing roller 208, a discharge port 209, and a discharge tray 210 are provided.

  The photosensitive drum 205 is uniformly charged by a charging device (not shown) while rotating in the direction of the arrow in the drawing.

  The exposure device 206 converts the modulation signal generated based on the image data of the original read by the original reading unit 500 into a laser beam and outputs it, and forms an electrostatic latent image on the photosensitive drum 205 for each color.

  The developing devices 207Y, 207M, 207C, and 207K supply each color developer to the photosensitive drum 205 to form a toner image for each color. The intermediate transfer roller 204 is transferred with the toner image of each color from the photosensitive drum 205, and a color toner image is formed on the intermediate transfer roller 204.

On the other hand, the paper feeding roller 202 pulls out the recording paper from the paper feeding cassette 201 in which the recording paper is stored, and feeds the recording paper to the transfer roller 203. The transfer roller 203 transfers the toner image on the intermediate transfer body roller 204 onto the conveyed recording paper, and the fixing roller 208 heats and fixes the transferred toner image on the recording paper. Thereafter, the recording paper is carried into the paper post-processing unit 300 from the discharge port 209 of the main body unit 200. The recording paper is also discharged to the discharge tray 210 as necessary.

  The paper post-processing unit 300 includes a carry-in port 301, a recording paper transport unit 302, a carry-out port 303, a stack tray 304, and the like.

  The recording paper transport unit 302 sequentially transports the recording paper carried into the carry-in port 301 from the discharge port 209 and finally ejects the recording paper from the carry-out port 303 to the stack tray 304. The stack tray 304 is configured to move up and down in the direction of the arrow in accordance with the number of recording sheets stacked from the carry-out port 303.

  FIG. 2 is a block diagram showing an example of the electrical configuration of the copying machine 1 shown in FIG. The copying machine 1 includes a scanner unit 11, a printer unit 21, an operation panel unit 31, a parallel I / F unit 51, a serial I / F unit 52, a storage unit 53, a power supply device 61, and a control unit 41. Further, the copying machine 1 is configured so that an optional device 71 configured to be detachable is attached to the main body 200 that executes the operation of the extended function of the copying machine 1 so that the extended function of the copying machine 1 can be operated. Yes.

  The scanner unit 11 includes an illumination light source 12 and an image sensor 13 that constitute the first scanner 501 shown in FIG. The image sensor 13 includes a CCD, for example. The scanner unit 11 irradiates the document with the illumination light source 12 and receives the reflected light with the image sensor 13, thereby reading an image from the document and obtaining image data (corresponding to image information) corresponding to the read image. Output to the control unit 41.

  The printer unit 21 includes a sheet conveying unit 22 including the sheet feeding cassette 201 and the sheet feeding roller 202 shown in FIG. 1, the intermediate transfer member roller 204, the photosensitive drum 205, the exposure device 206, and the developing device 207Y shown in FIG. , 207M, 207C, 207K, and the like, a transfer unit 24 including the transfer roller 203 shown in FIG. 1, and a fixing unit 25 including the fixing roller 208 shown in FIG. .

  Specifically, the paper transport unit 22 transports the recording paper to the image forming unit 23, the image forming unit 23 forms a toner image corresponding to the image data, and the transfer unit 24 transfers the toner image to the recording paper. Then, the fixing unit 25 fixes the toner image on the recording paper to form an image.

  The operation panel unit 31 includes a touch panel unit 32 including the touch panel 401 shown in FIG. 1 and an operation key unit 33 including the start key 402 and the numeric keypad 403 shown in FIG.

  The operation panel unit 31 is used by the user to perform operations related to the copy function, and gives an operation command or the like by the user to the control unit 41. The touch panel unit 32 includes a touch panel unit that combines a touch panel and an LCD (Liquid Crystal Display). The touch panel unit 32 displays information on various operation screens, for example, enlargement / reduction ratio setting, and the user touches the part. To display operation buttons and the like for inputting various operation commands. The operation key unit 33 is used by the user to input a print execution command or the like.

  The storage unit 53 is configured by a storage medium such as an HDD (hard disk drive), a non-volatile memory, or a RAM. The image data read by the scanner unit 11, the output format set for the image data, and various image processing It stores image data after (processing), an error log indicating the content of an abnormality that has occurred in each functional operation unit, and the like. Note that the writing of the image data to the storage unit 53 and the reading of the image data from the storage unit 53 are executed in accordance with instructions from the control unit 41.

  The parallel I / F unit 51 and the serial I / F unit 52 are interfaces for inputting / outputting data to / from an external computer.

  The power supply device 61 is provided in the copier 1 such as the optional device 71 mounted on the control unit 41, the printer unit 21, and the main body unit 200 by converting AC power supplied from the AC power source into DC power. Power is supplied to each functional operation unit.

  The control unit 41 incorporates a microcomputer having a memory such as a CPU, ROM and RAM, a dedicated hardware circuit, and the like, and controls the operation of the entire apparatus. Further, as will be described later, the control unit 41 operates by the second level DC power supplied from the second transformer provided in the power supply device 61, and functions as the drive control unit 42 and the abnormality detection unit 43. Have.

  The optional device 71 is configured to be detachable from the main body unit 200 and realizes an extended function of the copying machine 1. For example, by attaching a FAX modem as an optional device 71 to the main body 200, a facsimile function for transmitting and receiving FAX to an external computer is realized, or a LAN network interface is used as the optional device 71 for the main body 200. By mounting it on the printer, it is possible to realize a printer function for outputting image data received from an external computer via a network via the printer unit 21.

  FIG. 3 is a block diagram illustrating an example of a configuration of a functional operation unit related to the power supply device 61. The power supply device 61 includes a first transformer 62, a second transformer 63, a zero-cross signal output unit 64, and a switching unit 65.

  The first transformer 62 is configured to include an AC / DC converter, and converts AC power supplied from the AC power source AC into DC power of a predetermined first level (for example, 24V). The first transformer 62 is connected to the printer unit 21 such as each drive unit provided in the scanner unit 11 such as the illumination light source 12 and the image sensor 13, a motor that drives the paper feed roller 202 and the transfer roller 203, for example. The converted DC power is supplied to each of the drive units provided and the second transformer 63 provided at the subsequent stage of the first transformer 62.

  In the following description, the drive units that operate with the DC power output from the first transformer 62 are collectively referred to as a first DC load 91.

  The second transformer 63 includes a DC / DC converter, and converts the DC power output from the first transformer 62 into a DC power of a predetermined second level (for example, 5 V) different from the first level. Convert. The second transformer 63 operates with DC power having a lower voltage than the first DC load 91. For example, the parallel transformer 51, serial I / F 52, FAX board, printer board, etc. are optional. The converted DC power is supplied to each functional operation unit such as the device 71 and the control unit 41.

  In the following description, each functional operation unit that operates with the DC power output from the second transformer 63 is generically referred to as a second DC load 92.

  The zero cross signal output unit 64 outputs a zero cross signal to the control unit 41 in response to a zero cross point of AC power supplied from the AC power source AC (a point where the voltage waveform of the AC power indicates 0).

  The switching unit 65 is supplied to an AC load operated by AC power supplied from an AC power source AC, such as a fixing heater for heating the fixing roller 208 provided in the fixing unit 25 under the control of the drive control unit 42 described later. Switch on / off AC power. That is, the AC power supply to the AC load is switched between the supply state (ON) and the supply stop state (OFF) by the on / off switching control by the switching unit 65.

  The drive control unit 42 is operated by the second level (for example, 5V) DC power supplied from the second transformer 63 and, as part of the function of the control unit 41, the zero cross signal output from the zero cross signal output unit 64. In response to the control, the switching unit 65 is controlled to switch on and off.

  For example, the drive control unit 42 controls the switching unit 65 to turn on and off, thereby supplying AC power supplied to a fixing heater for heating the fixing roller 208 provided in the fixing unit 25 ( ON) and supply stop state (OFF) are switched, and the temperature of the fixing roller 208 is adjusted.

  A temperature sensor for detecting the temperature of the fixing heater or the fixing roller 208 is provided in the vicinity of the fixing heater or the fixing roller 208, and a detection signal indicating the temperature of the fixing heater or the fixing roller 208 detected by the temperature sensor is driven. It is configured to be input to the control unit 42.

  The drive control unit 42 feeds back the temperature of the fixing heater or the fixing roller 208 indicated by the detection signal output from the temperature sensor and switches the switching unit 65 on and off in response to the zero-cross signal. Adjust.

  FIG. 4 is a timing chart showing an example of a control signal (switching control signal) for controlling the on / off of the zero cross signal and the switching unit 65 by the drive control unit 42. When the switching control signal is at a high level, AC power is supplied to the fixing heater (on), and the fixing heater is in a heat generation state. When the switching control signal is at a low level, the supply of AC power to the fixing heater is stopped (off). The temperature gradually decreases.

  In the initial state, the drive control unit 42 is in a zero-cross interrupt request state, that is, the drive control unit 42 is in a state of accepting execution of an interrupt process in response to an input of a zero-cross signal. In synchronism with the rise of the zero cross signal at time t11, specifically, the drive control unit 42 temporarily cancels the zero cross interrupt request for a predetermined time using the rise of the zero cross signal as a trigger. In other words, the drive control unit 42 ignores (prohibits) the input of the zero cross signal until the execution of the interrupt process is completed after the zero cross signal is input.

  The drive control unit 42 temporarily cancels the zero-cross interrupt request in synchronization with the rising edge of the zero-cross signal, outputs a switching control signal to the switching unit 65 (time t12), supplies AC power to the fixing heater, The fixing heater is heated.

  Subsequently, the drive control unit 42 enters the zero cross interrupt request state again in synchronization with the output of the switching control signal. Then, the drive control unit 42 temporarily cancels the zero-cross interrupt request in synchronization with the rising of the zero-cross signal at time t13, and outputs a switching control signal to the switching unit 65 (time t14). As a result, the supply of AC power to the fixing heater is stopped (turned off), and the temperature of the fixing heater gradually decreases due to heat dissipation.

  As described above, the drive control unit 42 outputs the switching control signal in synchronization with the rising edge of the zero-cross signal, and the switching unit 65 receives the switching control signal output from the drive control unit 42 to input the fixing heater. Control to switch the heat generation state.

  Returning to FIG. 3, the abnormality detection unit 43 is operated by a second level (for example, 5 V) DC power supplied from the second transformer 63, and the first DC load 91, Detect at least one abnormality of the second DC load 92 or the AC load 93 that operates by AC power supplied from the AC power supply AC, and store the content of the abnormality in the storage unit 53 (FIG. 2), or The operator of the copying machine 1 is notified of the occurrence of the abnormality by displaying a message indicating the content of the abnormality on an LCD (Liquid Crystal Display) or the like provided in the operation panel 31 (FIG. 2).

  For example, as described above, a temperature sensor for detecting the temperature of the fixing heater is provided in the vicinity of the fixing heater for heating the fixing roller 208 as the AC load 93, and the fixing heater detected by the temperature sensor is provided. A detection signal indicating the temperature is input to the abnormality detection unit 43. In this case, the abnormality detection unit 43 assumes that a temperature abnormality has occurred in the fixing heater when the temperature of the fixing heater indicated by the detection signal deviates from the set value range stored in advance in the ROM or the like. The contents of the temperature abnormality are stored in the storage unit 53.

  Further, for example, a detection signal indicating the rotation speed output from a speed sensor that detects the rotation speed of a motor serving as the first DC load 91 that drives the paper feed roller 202, and a parallel I / O serving as the second DC load 92 are used. In the F unit 51 and the serial I / F unit 52, there is a control signal indicating that a data input / output error has occurred due to the fact that a cable used for data input / output with an external computer is not connected. It is configured to be output to the abnormality detection unit 43.

  In this case, the abnormality detection unit 43 causes an operation abnormality in the motor that drives the paper feed roller 202 when the rotation speed indicated by the detection signal deviates from the set value range stored in advance in the ROM or the like. As a result, the contents of the abnormal operation are stored in the storage unit 53. Further, when a control signal indicating that a data input / output abnormality has occurred in the parallel I / F unit 51 or the serial I / F unit 52 is input, the abnormality detection unit 43 displays the contents of the data input / output abnormality. Store in the storage unit 53.

  That is, the abnormality detection unit 43 causes each load 91 to deviate from the set value range stored in advance in the ROM or the like as the operation state indicated by the detection signal output from the sensor provided in each load 91, 92, 93. , 92, 93, or when a control signal indicating an abnormality is input from each of the loads 91, 92, 93, the contents of the abnormality are stored in the storage unit 53.

  Note that the abnormality detection unit 43 detects at least one abnormality of the first DC load 91, the second DC load 92, or the AC load 93 and stores the content of the abnormality in the storage unit 53. This is not a limited purpose.

  Further, when the zero-cross signal output from the zero-cross signal output unit 64 stops, the abnormality detection unit 43 has the second level (for example, 5 V) of DC power supplied from the second transformer 63 from the time of the stop. The content of the abnormality is not stored in the storage unit 53 until the voltage drops below this value.

  More specifically, as shown in FIG. 5, the power switch of the multifunction device 1 is turned on, and the AC power and the first level DC power are supplied via the AC power supply AC, the first transformer 62, or the second transformer 63. Alternatively, when the second level DC power is supplied to the AC load 93, the first DC load 91, or the second DC load 92 and each load is operating, for example, the outlet is disconnected from the AC power supply AC. When the supply of AC power is interrupted by, for example, the abnormality detection unit 43 detects that the zero cross signal output from the zero cross signal output unit 64 has stopped (S1; YES), and from the time of the stop, Operation until the DC power supplied from the second transformer 63 is in a standby state until the voltage drops below the second level (for example, 5 V) (predetermined time in the figure) and the contents of the abnormality are stored in the storage unit 53 Stop That (S2).

  Here, the time from when the zero cross signal stops until the DC power supplied from the second transformer 63 drops below the second level (for example, 5 V) (predetermined time in the figure) is, for example, The time until all the electric charges accumulated in the capacitor provided in the second transformer 63 are consumed by the second DC load 92 to rectify the DC power output from the second transformer 63 is shown.

  That is, during the period from when the zero cross signal is stopped until the DC power supplied from the second transformer 63 drops below a second level (for example, 5 V) (predetermined time in the figure), the second transformer. 63 is predicted in advance according to the charge capacity of the capacitor constituting 63, the number of second DC loads 92, and the like, and the predicted time is stored in the ROM provided in the storage unit 53 or the control unit 41. ing. In addition, it is not the meaning limited to this, The time input from the operator via the operation panel part 31 may be set.

  Note that the zero cross signal input to the abnormality detection unit 43 is the one in which the zero cross signal output from the zero cross signal output unit 64 to the drive control unit 42 is input to the abnormality detection unit 43 via the drive control unit 42. Also good.

  Returning to FIG. 5, the abnormality detection unit 43 starts from the time when the stop of the zero cross signal is detected in step S <b> 1 until the DC power supplied from the second transformer 63 drops below the second level (for example, 5 V). If it is determined that the interval has elapsed (S2; YES), if there is a second level of DC power supplied from the second transformer 63 (S3; YES), the detected abnormality is stored in the storage unit 53 (S4). ).

  On the other hand, the abnormality detection unit 43 has elapsed from the time when the stop of the zero cross signal is detected in step S1 until the DC power supplied from the second transformer 63 drops below the second level (for example, 5V). If the second level DC power is not supplied from the second transformer 63 (S3; NO), the DC power necessary to operate the abnormality detector 43 is supplied. Therefore, the operation of the abnormality detection unit 43 itself is stopped and terminated without executing the control for storing the detected abnormality content in the storage unit 53.

  That is, the power supply device 61 and the control unit 41 constitute an example of the power supply device according to the present invention.

  In the conventional power supply device, for example, when the AC power supplied from the AC power supply AC is interrupted, the operation of the first DC load 91, the second DC load 92, or the AC load 93 is continued, whereby the AC power, The power supplied from the first transformer 62 or the second transformer 63 is consumed, and a predetermined level of power is not supplied from the first transformer or the second transformer.

  When the operation of the first DC load 91, the second DC load 92, or the AC load 93 is stopped due to the fact that power of a predetermined level is not supplied, the first DC load 91, the second DC load 93 are stopped. 92, or the AC load 93 itself is not abnormal, but the first DC load 92, the second DC load 92, or the AC load 93 is abnormal and the operation is stopped. Control to store the contents of the abnormality.

  However, according to this configuration, when the zero cross signal output from the zero cross signal output unit 64 is stopped due to the AC power supplied from the AC power supply AC being cut off, the abnormality detection unit 43 is stopped. Until the DC power supplied from the second transformer 63 drops below the second level, the contents of the erroneous abnormality are not stored in the storage unit 53.

  For this reason, at the time when the period from when the zero cross signal is stopped until the DC power supplied from the second transformer 63 drops below the second level by the abnormality detector 43 has already passed, the second transformer. Since the second level DC power is no longer supplied from the unit 63, the abnormality detection unit 43 stops operating, and the abnormality detection unit 43 is prevented from storing the contents of the erroneous abnormality in the storage unit 53. .

  In addition, the zero cross signal output from the zero cross signal output unit 64 used in the abnormality detection unit 43 is configured to be used for the control of the switching unit 65 in the drive control unit 42. There is no need to newly provide a functional operation unit for detecting that AC power is cut off, such as providing a detection unit for detecting whether or not the AC power is cut off and providing a new signal line connected to the detection unit. For this reason, the abnormality detection unit 43 can be configured at low cost.

  In the above-described embodiment, as an example of the electrical apparatus, a copying machine that is an image forming apparatus including a fixing heater that is heated by AC power supplied from an AC power source has been described as an example. Other electrical devices including a functional operation unit that performs control using a zero-cross signal of AC power supplied from an AC power source, such as an image forming apparatus such as a personal computer, a TV, or a refrigerator.

  In the above embodiment, the configurations and settings shown in FIGS. 1 to 5 are merely examples, and the present invention is not limited to the embodiment.

1 Copying machine (electrical equipment)
25 fixing section 41 control section 42 drive control section 43 abnormality detection section 53 storage section 61 power supply device 62 first transformer section 63 second transformer section 64 zero cross signal output section 65 switching section 91 first DC load (DC load)
92 Second DC load (DC load)
93 AC load AC AC power supply

Claims (3)

A storage unit;
A switching unit that switches on and off the AC power supplied to an AC load operated by AC power supplied from an AC power source;
A first transformer that converts AC power supplied from the AC power source into predetermined first level DC power;
A second transformer for converting DC power output from the first transformer into a predetermined second-level DC power different from the first level;
A zero cross signal output unit that outputs a zero cross signal in response to a zero cross point of the AC power supplied from the AC power supply;
A drive control unit that operates by direct current power supplied from the second transformer, and controls the switching unit to switch on and off in response to the zero-cross signal;
A first DC load that operates with DC power supplied from the second transformer, a first DC load that operates with DC power supplied from the first transformer, and a second that operates with DC power supplied from the second transformer. An abnormality detection unit that detects at least one abnormality of the DC load or the AC load and stores the content of the abnormality in the storage unit;
With
When the zero-cross signal is stopped, the abnormality detection unit is configured to perform a description of the abnormality from the time when the zero-crossing signal is stopped until the DC power supplied from the second transformer unit drops below the second level. Is a power supply device that does not store in the storage unit. The power supply device according to claim 1, the AC load, the first load or the second load,
Electrical equipment comprising. A power supply device according to claim 1;
A fixing heater for heating with AC power supplied from the AC power source as the AC load;
An image forming apparatus comprising:
The switching unit switches on / off of AC power supplied to the fixing heater,
When the zero-cross signal is stopped, the abnormality detection unit performs a period from the time when the zero-crossing signal is stopped until the DC power supplied from the second power transformation unit drops below the second level. An image forming apparatus that does not store abnormal contents in the storage unit.

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