JP5439354B2 - Power supply device, image forming apparatus - Google Patents

Description

  The present invention relates to a power supply device and an image forming apparatus.

  There is an image forming apparatus having a normal mode and a sleep mode. In order to enable this type of image forming apparatus to execute the normal mode and the sleep mode, for example, a power supply device described in Patent Document 1 is used.

  The power supply device described in Patent Document 1 includes a high-capacity main power source and a small-capacity sub power source, and the main power source and the sub power source each supply output power to a load.

  In the normal mode, the power supply apparatus supplies output power to the load by the main power supply and the sub power supply, and in the sleep mode, supplies output power to the load only by the sub power supply.

  High-capacity power supplies are designed to be optimized for large power output. For this reason, it is more efficient to output a certain amount of high power than to output a small amount of power.

  On the other hand, a small-capacity power supply is designed to be optimized for a small power output. For this reason, the output of smaller power than the high-capacity power supply is more efficient than the output of large power.

  According to the power supply apparatus, as described above, in the normal mode in which the power consumption of the load is large, the output power is supplied by the high-capacity main power supply and the small-capacity sub power supply, and the power consumption of the load is smaller than in the normal mode In the sleep mode, the output power is supplied only by a small-capacity sub-power supply that is highly efficient at the time of low power output, so that the efficiency is good in both the normal mode and the sleep mode.

JP 2005-151672 A

  Incidentally, when power is supplied from the main power supply and the sub power supply in the normal mode and power is supplied only from the sub power supply in the sleep mode, the following problems occur.

  That is, in the normal mode, the output power from the main power supply and the output power from the sub power supply are supplied to the load at the same time.

  At this time, the main power supply is more efficient if it outputs a large amount of power, and the sub power supply is more efficient if it outputs less power than the main power supply. The larger the total, the higher the overall efficiency of the main power supply and the sub power supply.

  Therefore, the output power of the main power supply is made larger than the output power of the sub power supply by setting the output voltage of the main power supply higher than the output voltage of the sub power supply.

  However, since the voltage value of the output power from the sub power supply is adjusted to the operating voltage of the load so that the load can operate in the sleep mode, if the output power is supplied from the main power supply in the normal mode, the output from the main power supply The voltage value of power exceeds the operating voltage of the load.

  In this case, a converter that steps down the voltage value of the output power supplied from the main power supply to the operating voltage of the load needs to be arranged on the load side so that the load can operate in the normal mode. If it does so, the cost of a power supply device will increase, and efficiency will fall.

  SUMMARY An advantage of some aspects of the invention is that it provides a power supply apparatus and an image forming apparatus that can suppress a reduction in cost and efficiency.

  A power supply apparatus according to one aspect of the present invention includes a normal power supply unit that supplies output power of a first voltage value that is an operating voltage of a load to the load, the first voltage value, and the first voltage value. A sleep power supply unit that supplies any one of output power of a small second voltage value to the load, a normal mode that does not suppress power consumption of the load, and a sleep mode that suppresses power consumption of the load; A control unit that controls the normal power supply unit and the sleep power supply unit, and the control unit is configured to supply output power of the first voltage value to the load by the normal power supply unit in the normal mode. Then, the sleep power supply unit supplies the output power of the second voltage value to the load, and when the normal mode shifts to the sleep mode, the supply of the output power by the normal power supply unit is stopped. The voltage value of the output power by the sleep power supply unit, and changing from the second voltage value to the first voltage value.

  According to this configuration, in the normal mode, the control unit supplies the output power of the first voltage value, which is the operating voltage of the load, to the load by the normal power supply unit, while the sleep power supply unit uses the first voltage value from the first voltage value. The output power of the second voltage value having a small voltage value is also supplied.

  When the control unit shifts from the normal mode to the sleep mode, the control unit stops the supply of output power from the normal power supply unit, and the voltage value of the output power from the sleep power supply unit is changed from the second voltage value to the first voltage value. change.

  Thereby, in the normal mode, the output power having the first voltage value larger than the voltage value by the sleep power supply unit is supplied to the load by the normal power supply unit.

  When the normal mode shifts to the sleep mode, the supply of output power to the load by the normal power supply unit is stopped, and the voltage value of the output power from the sleep power supply unit is changed from the second voltage value to the first voltage value. The

  Therefore, in the normal mode, the output power of the load operating voltage is supplied to the load by the normal power supply unit, and in the sleep mode, the output power of the load operating voltage is supplied to the load by the sleep power supply unit.

  As a result, there is no need to place a converter on the load side that steps down the voltage value of the output power from the normal power supply unit, which is a voltage value larger than the operating voltage of the load, to the operating voltage of the load. Can be suppressed.

  In the above configuration, the normal power supply unit receives an input of commercial AC power and generates output power of the first voltage value. When the input of the commercial AC power is cut off, the input of the commercial AC power is cut off. For a predetermined output holding time after being supplied, supply the output power of the holding voltage value that is a voltage value within a predetermined voltage range including the first voltage value, and then stop supplying the output power, When the control unit shifts from the normal mode to the sleep mode, the control unit blocks the input of the commercial AC power to the normal power supply unit, and then the sleep power supply unit until the output holding time elapses. It is preferable to change the voltage value of the output power by the first voltage value.

  Here, the output holding time is a time during which the output power having a voltage value within a predetermined voltage range including the first voltage value is supplied after the input of the commercial AC power to the normal power supply unit is cut off. .

  According to this configuration, when the control unit shifts from the normal mode to the sleep mode, the control unit cuts off the input of commercial AC power to the normal power supply unit, and then includes the first voltage value that is the operating voltage of the load in advance. The voltage value of the output power by the sleep power supply unit is changed to the first voltage value until the output holding time during which the output power of the holding voltage value that is a voltage value within a predetermined voltage range is supplied.

  Thereby, even if the input of commercial AC power to the normal power supply unit is cut off, the supply of output power to the load by the sleep power supply unit while the output power of the holding voltage value is supplied to the load by the normal power supply unit Is started.

  As a result, it is possible to shift from the normal mode to the sleep mode without interrupting the supply of output power having a voltage value required by the load to the load.

  In addition, an image forming apparatus according to another aspect of the present invention includes the above-described power supply device, an image reading unit that reads image data of a document, and image formation that forms image data read by the image reading unit on a recording sheet. And a section.

  According to this configuration, since the power supply device described above is provided, it is possible to suppress a reduction in cost and efficiency.

  According to the present invention, reduction in cost and efficiency can be suppressed.

1 is a longitudinal sectional view schematically showing an example of a configuration of an image forming apparatus according to an embodiment of the present invention. It is the block diagram which showed an example of the functional module of the power supply device which concerns on one Embodiment of this invention. It is the flowchart which showed an example of the outline | summary of the basic operation | movement of a power supply device. It is the time chart which showed an example of the outline | summary of the basic operation | movement of a power supply device.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view schematically showing an example of the configuration of an image forming apparatus according to an embodiment of the present invention. The image forming apparatus A in FIG. 1 includes the power supply device 1 (see FIG. 2) according to an embodiment of the present invention.

  The image forming apparatus A includes an image reading unit 200 and an image forming main body unit 3. The image reading unit 200 includes a document feeding unit 210, a scanner main body 220, a CIS 231, a user interface unit I disposed so as to be exposed on the front surface of the scanner main body 220, and a reversing mechanism described later.

  The document feeder 210 includes an ADF (Automatic Document Feeder), and includes a document tray 211, a pickup roller 212, a platen 213, a paper discharge roller 214, and a paper discharge tray 215.

  A document to be read is placed on the document tray 211. Documents placed on the document tray 211 are picked up one by one by the pickup roller 212 and sequentially conveyed to the platen 213 through the gap. Documents that have passed through the platen 213 are sequentially discharged to the discharge tray 215 by the discharge rollers 214.

  Of the positions facing the peripheral surface of the platen 213, a timing sensor (not shown) for detecting paper is installed at a predetermined position before the reading position P in the document transport direction. The document transport timing to the reading position P is achieved based on the output request. The timing sensor is configured by, for example, a photo interrupter.

  The scanner main body 220 optically reads image data of a document and generates image data. The scanner main body 220 includes a glass 221, a light source 222, a first mirror 223, a second mirror 224, a third mirror 225, a first carriage 226, a second carriage 227, an imaging lens 228, and a line sensor 229.

  In the scanner main body 220, the light emitted from the light source 222 is reflected by the original on the glass 221 to become reflected light, and this reflected light is used as the first mirror 223, the second mirror 224, the third mirror 225, and the first carriage. 226, the second carriage 227, and the imaging lens 228 are guided to the line sensor 229.

  The light guided to the line sensor 229 is converted by the line sensor 229 into charges representing image data.

  On the glass 221, a document is manually placed by the user when reading the document without using the document feeder 210. The light source 222 and the first mirror 223 are supported by the first carriage 226, and the second mirror 224 and the third mirror 225 are supported by the second carriage 227.

  As the document reading method of the image reading unit 200, the scanner body 220 reads a document placed on the glass 221 and the document is read by the document feeder 210 (ADF). There is an ADF reading mode for reading.

  In the flatbed reading mode, the light source 222 irradiates a document placed on the glass 221, and reflected light for one line in the main scanning direction is reflected in the order of the first mirror 223, the second mirror 224, and the third mirror 225. Then, the light enters the imaging lens 228. The light incident on the imaging lens 228 is imaged on the light receiving surface of the line sensor 229.

  The line sensor 229 is a one-dimensional image sensor, and processes the image data of one line of document in an overlapping manner. The first carriage 226 and the second carriage 227 are configured to be movable in a direction orthogonal to the main scanning direction (sub-scanning direction Y). When reading of one line is completed, the first carriage 226 is moved in the sub-scanning direction. Then, the second carriage 227 moves and the next line is read.

  In the ADF reading mode, the document feeder 210 takes in the documents placed on the document tray 211 one by one by the pickup roller 212. At this time, the first carriage 226 and the second carriage 227 are disposed at a predetermined reading position P located below the reading window 230.

  When the document is transported by the document feeder 210, when the document passes over the reading window 230 provided in the transport path from the platen 213 to the paper discharge tray 215, the light source 222 irradiates the document, and the main scanning one line. The reflected light is reflected in the order of the first mirror 223, the second mirror 224, and the third mirror 225 and enters the imaging lens 228. The light incident on the imaging lens 228 is imaged on the light receiving surface of the line sensor 229. Subsequently, the document is conveyed by the document feeder 210 and the next line is read.

  Further, the document feeder 210 has a reversing mechanism including a switching guide 216, a reversing roller 217, and a reversing conveyance path 218. The reversing mechanism reverses the front and back of the original whose surface has been read by the first ADF reading and transports it again to the reading window 230, so that the line sensor 229 reads the back side again.

  This reversing mechanism operates only when reading both sides and does not operate when reading one side. After reading the back side during single-sided reading and double-sided reading, the switching guide 216 is switched to the upper side, and the document that has passed through the platen 213 is discharged to the discharge tray 215 by the discharge roller 214.

  After the front side reading at the time of double-sided reading, the switching guide 216 is switched to the lower side, and the document that has passed through the platen 213 is transported to the reverse transport path 218 by the reverse roller 217. Thereafter, the switching guide 216 is switched upward, and the reverse roller 217 rotates in the reverse direction to re-feed the document to the platen 213. Hereinafter, a mode in which both sides of a document are read using a reversing mechanism is referred to as a double-sided reversal reading mode.

  Further, in the ADF reading mode, the image reading unit 200 according to the present embodiment substantially overlaps when the line sensor 229 (scanner body 220) reads the surface of the document during the conveyance of the document as described above ( It is possible to read the back side of the document by the CIS 231 (substantially in parallel). In this case, the document conveyed from the document tray 211 by the document feeder 210 is read by the line sensor 229 when passing over the reading window 230 and further read by the back side when passing through the location where the CIS 231 is disposed. It is done. In CIS231, RGB three-color LEDs or the like are used as light sources.

  By using the line sensor 229 and the CIS 231 in this way, it is possible to read both the front and back sides of a document by a single document transport operation (one pass) from the document tray 211 to the paper discharge tray 215 by the document feeding unit 210.

  The image forming apparatus A includes an image forming main body 3 and a stack tray 6 disposed on the left side of the image forming main body 3. The image forming main body 3 has been transported from a plurality of paper feed cassettes 461, a paper feed roller 462 for feeding recording sheets from the paper feed cassette 461 one by one to the image forming unit 40, and a paper feed cassette 461. And an image forming unit 40 that forms image data on recording paper. In addition, the image forming main body 3 includes a paper feed tray 471 and a feeding roller 472 that feeds the originals placed on the paper feed tray 471 one by one toward the image forming unit 40.

  The image forming unit 40 removes the residual charge from the surface of the photosensitive drum 43, the charging device 422 that charges the surface of the photosensitive drum 43 after static elimination, and the image data acquired by the scanner main body 220. Based on the electrostatic latent image, an exposure device 423 that outputs a laser beam to expose the surface of the photosensitive drum 43 to form an electrostatic latent image on the surface of the photosensitive drum 43. Above, developing devices 44K, 44Y, 44M, and 44C that form toner images of cyan (C), magenta (M), yellow (Y), and black (K), and various colors formed on the photosensitive drum 43. A transfer drum 49 on which the toner image data is transferred and superimposed, a transfer device 41 for transferring the toner image on the transfer drum 49 to the paper, and heating the paper on which the toner image is transferred. And a fixing device 45 for fixing the toner image to the sheet.

  The cyan, magenta, yellow, and black colors are supplied from a toner cartridge (not shown). Further, conveyance rollers 463 and 464 that convey the recording paper that has passed through the image forming unit 40 to the stack tray 6 or the discharge tray 48 are provided.

  When forming image data on both sides of the recording paper, the image forming unit 40 forms image data on one side of the recording paper, and then the recording paper is nipped by the conveyance roller 463 on the discharge tray 48 side. To do. In this state, the conveyance roller 463 is reversed to switch back the recording paper, and the recording paper is sent to the paper conveyance path L and is conveyed again to the upstream area of the image forming unit 40. Then, the recording paper is discharged to the stack tray 6 or the discharge tray 48.

  The user interface unit I includes a power switch (not shown). When the power switch is on, the power supply device 1 starts supplying output power to each unit of the image forming apparatus A. When the power switch is off, The supply of output power by the device 1 is stopped.

  FIG. 2 is a block diagram showing an example of a functional module of the power supply device according to the embodiment of the present invention. The power supply device 1 includes a sleep power supply unit 11 and a normal power supply unit 12, and the sleep power supply unit 11 and the normal power supply unit 12 are each connected to a control unit (load) 10.

  The control unit 10 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like, and is realized by the CPU executing a predetermined control program.

  The control unit 10 is arranged as a load of the sleep power supply unit 11 and the normal power supply unit 12. The control unit 10 uses the first voltage value V1 as an operation power supply voltage (operation voltage). Then, the control unit 10 controls the sleep control unit 110 arranged in the sleep power supply unit 11 and the relay circuits RY1 and RY2 arranged in the normal power supply unit 12.

  The control unit 10 has a sleep mode in which the power consumption of the control unit 10 is suppressed and a normal mode in which the power consumption of the control unit 10 is not suppressed.

  Here, the sleep mode is a mode in which, for example, the frequency of the operation clock of the CPU in the control unit 10 is lower than the normal mode, and the normal mode is, for example, the frequency of the operation clock of the CPU in the control unit 10 Is a higher mode.

  This can be realized by the CPU multiplying or dividing the frequency of the clock output from the clock signal output unit (not shown) in the control unit 10 to the CPU.

  Thereby, the power consumption of the control unit 10 is suppressed in the sleep mode, and the power consumption of the control unit 10 is not suppressed in the normal mode.

  In the normal mode, the control unit 10 outputs the H level voltage signal as a mode control signal to the sleep control unit 110 and the relay circuits RY1 and RY2, and when the mode is shifted to the sleep mode, the control unit 10 outputs the L level voltage signal. The signal is output as a mode control signal to the sleep control unit 110 and the relay circuits RY1 and RY2.

  The sleep power supply unit 11 and the normal power supply unit 12 are configured by, for example, a switching power supply circuit.

  The sleep power supply unit 11 is a power supply circuit having a smaller capacity than that of the normal power supply unit 12, and outputs output power having a lower power than that of the normal power supply unit 12 to the control unit 10. The sleep power supply unit 11 receives commercial AC power input from the commercial AC power supply AC through the power supply line L, and outputs power of the first voltage value V1 that is the operating voltage of the control unit 10 and the first voltage value V1. Any one of the output powers of the smaller second voltage value V2 is supplied to the control unit 10.

  One normal power supply unit 12 is a power supply circuit having a capacity larger than that of the sleep power supply unit 11, and outputs an output power larger than that of the sleep power supply unit 11 to the control unit 10. The normal power supply unit 12 receives the commercial AC power input from the commercial AC power supply AC through the power supply line L, and supplies the control unit 10 with the output power of the first voltage value V1 that is the operating voltage of the control unit 10.

  Here, for example, depending on the difference between the size of the transformer TR1 and the size of the transformer TR2, the difference between the rating of the switching element Q1 and the rating of the switching element Q2, and the difference between the capacity of the smoothing capacitor C1 and the capacity of the smoothing capacitor C3. The difference between the capacity of the sleep power supply unit 11 and the capacity of the normal power supply unit 12 is determined.

  Since the normal power supply unit 12 has a larger capacity than the sleep power supply unit 11, the size of the transformer TR2 is larger than the size of the transformer TR1, the rating of the switching element Q2 is larger than that of the switching element Q1, and the smoothing capacitor C3 The capacity is larger than the capacity of the smoothing capacitor C1.

  Specifically, the sleep power supply unit 11 rectifies commercial AC power from which noise is removed by the noise filter 111 for removing commercial AC power noise input from the commercial AC power supply AC through the power line L, and the noise filter 111. A diode bridge DB1, a smoothing capacitor C1 that smoothes the commercial AC power rectified by the diode bridge DB1, a transformer TR1 that transforms the voltage value of the commercial AC power smoothed by the smoothing capacitor C1 to a predetermined voltage value, and a smoothing capacitor Switching element Q1 for inputting commercial AC power smoothed by C1 to transformer TR1 at a predetermined cycle, diode D2 for rectifying commercial AC power transformed by transformer TR1, and commercial AC power rectified by diode D2 Smooth The capacitor C2, the diode D3 that rectifies the commercial AC power smoothed by the smoothing capacitor C2, the sleep control unit 110 that controls the sleep power supply unit 11, and the sleep control unit 110 are configured to output power supplied from the sleep power supply unit 11. Resistors R1 and R2 for monitoring the voltage value are provided.

  In the sleep power supply unit 10 having such a configuration, the sleep control unit 110 includes a CPU, a RAM, a ROM, and the like, and is realized by the CPU executing a predetermined control program.

  The sleep control unit 110 outputs a pulse signal having a predetermined frequency for driving the switching element Q1 to the switching element Q1. The sleep control unit 110 monitors the voltage value of the output power supplied from the sleep power supply unit 11 with reference to the voltage value of the connection part between the resistor R1 and the resistor R2, and outputs from the sleep power supply unit 11 The frequency of the pulse signal output to the switching element Q1 is controlled so that the voltage value of power becomes the first voltage value V1 or the second voltage value V2.

  In the sleep power supply unit 11 having this configuration, the noise is removed from the commercial AC power supplied through the power line L by the noise filter 111, and the commercial AC power after the noise is rectified by the diode bridge DB1, and the commercial AC after rectification The electric power is smoothed by the smoothing capacitor C1. Thereby, commercial AC power is converted into DC power.

  Then, the DC power obtained by the diode bridge DB1 and the smoothing capacitor C1 is intermittently output to the primary side of the transformer TR1 at the timing when the switching element Q1 is turned on.

  Here, the timing at which the DC power obtained by the diode bridge DB1 and the smoothing capacitor C1 is output to the primary side of the transformer TR1 is determined by the frequency of the pulse signal output to the switching element Q1. The frequency of the pulse signal is controlled by the sleep control unit 110 so that the voltage value of the output power supplied from the sleep power supply unit 11 becomes the first voltage value V1 or the second voltage value V2.

  The DC power intermittently output to the primary side of the transformer TR1 is transformed according to the turns ratio between the primary and secondary turns of the transformer TR1, the switching frequency of the switching element Q1, the switching duty ratio, and the like. The transformed DC power is output from the secondary side of the transformer TR1. Thereby, the transformed DC power is intermittently output from the secondary side of the transformer TR1.

  Then, the DC power intermittently output from the secondary side of the transformer TR1 is rectified by the diode D2, the rectified power is smoothed by the smoothing capacitor C2, and the smoothed power is further rectified by the diode D3. The subsequent power is supplied to the control unit 10 as output power.

  The voltage value of the output power is determined by the frequency or duty ratio of the pulse signal output from the sleep control unit 110 to the switching element Q1, and the sleep control unit 110 is at the H level from the control unit 10 that has shifted to the normal mode. When the voltage signal is received, the frequency or duty ratio of the pulse signal is controlled so that the voltage value of the output power becomes the second voltage value V2.

  On the other hand, when the sleep control unit 110 receives an L-level voltage signal from the control unit 10 that has shifted to the sleep mode, the voltage value of the output power becomes the first voltage value V1 that is larger than the second voltage value V2. The frequency or duty ratio of the pulse signal is controlled.

  Thereby, the sleep power supply unit 11 supplies the output power of the second voltage value V2 to the control unit 10 when the control unit 10 shifts to the normal mode, and the second voltage when the control unit 10 shifts to the sleep mode. The output power of the first voltage value V1 larger than the value V2 is supplied to the control unit 10.

  One normal power supply unit 12 specifically includes a noise filter 121 for removing noise of commercial AC power input from the commercial AC power supply AC through the power line L, and between the noise filter 121 and the commercial AC power supply AC. The relay circuits RY1 and RY2 arranged in the circuit, the diode bridge DB2 that rectifies the commercial AC power from which noise has been removed by the noise filter 121, the smoothing capacitor C3 that smoothes the commercial AC power rectified by the diode bridge DB2, and the smoothing capacitor C3. A transformer TR2 for transforming the smoothed commercial AC power voltage value to a predetermined voltage value, a switching element Q2 for inputting the commercial AC power smoothed by the smoothing capacitor C3 to the transformer TR2 in a predetermined cycle, and a transformer TR2 Commercial AC power transformed by A smoothing capacitor C4 that smoothes commercial AC power rectified by the diode D5, a diode D6 that rectifies commercial AC power smoothed by the smoothing capacitor C4, a normal control unit 120 that controls the normal power supply unit 12, The normal control unit 120 includes resistors R3 and R4 for monitoring the voltage value of the output power supplied from the normal power supply unit 12.

  In this normal power supply unit 12, except for the relay circuits RY <b> 1 and RY <b> 2 and the normal control unit 120, the description is omitted because it is the same as the sleep power supply unit 11.

  The relay circuits RY1 and RY2 are circuits that cut off the input of commercial AC power to the noise filter 121. The relay circuits RY1 and RY2 are turned on when an H level voltage signal is received from the control unit 10, and the L level voltage signal is output from the control unit 10. Turn off when you accept.

  The normal control unit 120 includes a CPU, a RAM, a ROM, and the like, and is realized by the CPU executing a predetermined control program.

  The normal control unit 120 outputs a pulse signal having a predetermined frequency for driving the switching element Q2 to the switching element Q2. The normal control unit 120 monitors the voltage value of the output power supplied from the normal power supply unit 12 with reference to the voltage value of the connection part between the resistor R3 and the resistor R4, and the output power supplied from the normal power supply unit 12 The frequency or duty ratio of the pulse signal output to the switching element Q2 is controlled so that the voltage value becomes the first voltage value V1.

  Thereby, when the control part 10 transfers to normal mode, since the relay circuits RY1 and RY2 are turned on, the normal power supply part 12 supplies the output power of the first voltage value V1 to the control part 10, and the control part 10 When the mode is shifted to the sleep mode, the relay circuits RY1 and RY2 are turned off to cut off the input of the commercial AC power, so that the supply of the output power is stopped after a predetermined output holding time.

  In the normal power supply unit 12, when the input of the commercial AC power is cut off while the normal power supply unit 12 supplies the output power of the first voltage value V1, which is a constant voltage, the charge charged in the smoothing capacitor C4. Is discharged.

  Thereby, in the normal power supply unit 12, the voltage value of the output voltage by the normal power supply unit 12 is within a certain voltage range including the first voltage value V1 during the output holding time from when the input of the commercial AC power is cut off. Is maintained at a holding voltage value V3. When the output holding time elapses, the voltage value of the output voltage from the normal power supply unit 12 drops to a voltage less than the holding voltage value V3. Such a characteristic is a characteristic that a known power supply circuit normally has.

  The holding voltage value V3 is a voltage value within a range between the first voltage value V1 and a voltage value that is extremely smaller than the first voltage value V1, and the control unit 10 that uses the first voltage value V1 as an operating voltage is used. , A voltage value that can be operated by receiving the output power of the holding voltage value V3.

  The output holding time during which the output power having the holding voltage value V3 is supplied is determined by the voltage value of the commercial AC power, the capacity of the smoothing capacitor C1, the minimum regulation voltage, the efficiency, and the current value of the output power.

  FIG. 3 is a flowchart showing an example of an outline of the basic operation of the power supply apparatus.

  When a power switch (not shown) arranged in the user interface unit I is turned on (YES in step S1), the control unit 10 executes the normal mode (step S2) and turns on the relay circuits RY1 and RY2 (step S2). Step S3).

  Then, the control unit 10 causes the normal power supply unit 12 to output the output power of the first voltage value V1 toward the control unit 10, while the sleep power supply unit 11 outputs the output power of the second voltage value V2 to the control unit 10. Output. At this time, since the first voltage value V1 is larger than the second voltage value V2, the output power from the normal power supply unit 12 is supplied to the control unit 10 in preference to the sleep power supply unit 11.

  Then, when it is time to shift to the sleep mode (YES in step S5), the control unit 10 proceeds to step S6. In addition, as a timing which should transfer to sleep mode, the time when the operation part 18 of the user interface part I was not operated for a predetermined time is mentioned, for example.

  In step S6, the control unit 10 shifts to the sleep mode. Then, the control unit 10 turns off the relay circuits RY1 and RY2 (step S7), and causes the sleep control unit 110 to change the voltage value of the output power from the normal power supply unit 12 to the first voltage value V1 (step S8). ).

  Here, after the relay circuits RY1 and RY2 are turned off and the input of the commercial AC power to the normal power supply unit 12 is cut off, the normal power supply unit 12 includes the first voltage value V1 during the output holding time. The output power having the holding voltage value V <b> 3 is supplied toward the control unit 10.

  The sleep control unit 110 preferably changes the voltage value of the output power from the sleep power supply unit 11 to the first voltage value V1 before such output holding time elapses. For example, as soon as the voltage signal from the control unit 10 is switched from the H level to the L level, the sleep control unit 110 changes the voltage value of the output power from the sleep power supply unit 11 to the first voltage value V1.

  If the voltage value of the output power from the sleep power supply unit 11 is changed to the first voltage value V1 before the output holding time elapses, the control unit 10 will have the control unit 10 when the control unit 10 shifts from the normal mode to the sleep mode. There is an advantage that the output power of the voltage value required by the control unit 10 is supplied without interruption.

  And when the timing which should transfer to normal mode comes (YES of step S9), the control part 10 progresses to step S2. In addition, as a timing which should transfer to normal mode, the time when the operation part 18 of the user interface part I is operated is mentioned, for example.

  The effect of the power supply device 1 that performs the above basic operation will be described with reference to FIG. FIG. 4 is a time chart showing an example of an outline of the basic operation of the power supply device.

  Here, the holding voltage value V3 is a voltage value within a range between the first voltage value V1 and a voltage value very small than the first voltage value V1, and is a voltage value at which the control unit 10 can operate. . Therefore, hereinafter, the holding voltage value V3 is treated as the same voltage value as the first voltage value V1.

  4A represents the voltage value of the output power by the normal power supply unit 12, and the thin line in FIG. 4A represents the voltage value of the output power by the sleep power supply unit 11. A solid line in FIG. 4B represents a mode control signal output by the control unit 10. 4A and 4B, the vertical axis represents the voltage value, and the horizontal axis represents the elapsed time.

  Moreover, the solid line in FIG. 4C represents the mode of the control unit 10. In FIG. 4C, the vertical axis represents the mode of the control unit 10, and the horizontal axis represents elapsed time.

  Hereinafter, the effect of the power supply apparatus will be described with reference to FIG.

  As shown in FIG. 4C, when the control unit 10 shifts to the normal mode, the control unit 10 outputs an H level voltage signal to the sleep power supply unit 11 and the normal power supply unit 12 as shown in FIG. Therefore, as shown in FIG. 4A, output power of the second voltage value V2 is supplied from the sleep power supply unit 11 to the control unit 10, and output power of the first voltage value V1 is supplied from the normal power supply unit 12. Is supplied to the control unit 10.

  When the control unit 10 shifts from the normal mode to the sleep mode as shown in FIG. 4C, the control unit 10 sends the L level voltage signal to the sleep power supply unit 11 and the sleep mode as shown in FIG. Usually output to the power supply unit 12.

  In the normal power supply unit 12, when the normal power supply unit 12 receives the L level voltage signal, the relay circuits RY1 and RY2 are turned off, so that the input of commercial AC power is immediately cut off.

  Then, after the input of the commercial AC power is cut off, the normal power supply unit 12 outputs the output power of the holding voltage value that is the first voltage value V1 to the control unit 10 for the output holding time, and holds the output. After the elapse of time, the voltage value of the output power is reduced to zero.

  The sleep control unit 110 changes the voltage value of the output power from the sleep power supply unit 11 to the first voltage value V1 until the output holding time elapses after the input of the commercial AC power to the normal power supply unit 12 is interrupted. To do.

  As described above, in the power supply device 1, when the control unit 10 shifts from the normal mode to the sleep mode, the normal power supply unit 12 supplies the control unit 10 with output power having a holding voltage value at which the control unit 10 can operate. During the output holding time, the voltage value of the output power by the sleep power supply unit 11 is changed to the first voltage value V1 that is the operating voltage of the control unit 10.

  Accordingly, when the normal mode is shifted to the sleep mode, the output power of the first voltage value V1 that is the operation voltage of the control unit 10 is supplied to the control unit 10 without interruption. Therefore, the control unit 10 can stably operate when the normal mode is shifted to the sleep mode.

  Further, in both the normal mode and the sleep mode, the control unit 10 is supplied with the output power of the first voltage value V1 that is the operation voltage of the control unit 10, so that the voltage value is larger than the operation voltage of the control unit 10. Since it is not necessary to arrange on the control unit 10 side a converter that steps down the voltage value of the output power from the normal power supply unit 12 to the operating voltage of the control unit 10, it is possible to suppress cost and efficiency reduction.

A Image forming apparatus 1 Power supply device 10 Control unit 11 Sleep power supply unit 12 Normal power supply unit 40 Image forming unit 200 Image reading unit

Claims (3)

A normal power supply for supplying the load with output power of a first voltage value that is an operating voltage of the load;
A sleep power supply unit that supplies either one of the first voltage value and output power of a second voltage value smaller than the first voltage value to the load;
A normal mode that does not suppress power consumption of the load, and a sleep mode that suppresses power consumption of the load, and a control unit that controls the normal power supply unit and the sleep power supply unit,
The controller is
In the normal mode, the normal power supply unit supplies the output power of the first voltage value to the load, while the sleep power supply unit supplies the output power of the second voltage value to the load. When the transition to the sleep mode, the supply of the output power by the normal power supply unit is stopped, and the voltage value of the output power by the sleep power supply unit is changed from the second voltage value to the first voltage value. A power supply characterized by. The normal power supply unit receives an input of commercial AC power and generates output power of the first voltage value. When the input of the commercial AC power is shut off, the normal power source is predetermined after the input of the commercial AC power is shut off. During the output holding time, supply the output power of the holding voltage value that is a voltage value within a predetermined voltage range including the first voltage value, and then stop supplying the output power,
The controller is
When the transition from the normal mode to the sleep mode, the input of the commercial AC power to the normal power supply unit is cut off, and then the voltage of the output power by the sleep power supply unit until the output holding time elapses. The value is changed to the first voltage value. The power supply device according to claim 1, wherein: The power supply device according to claim 1 or 2,
An image reading unit for reading image data of a document;
An image forming unit for forming image data read by the image reading unit on a recording sheet;
An image forming apparatus comprising:

Images