JP2004268342A - Image formation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image formation device which reduces power consumption by improving the power use efficiency at the time of a power saving mode or when a cover of a device body is in an open state. <P>SOLUTION: The image formation device has a switching power supply 1 which supplies a 24 V voltage to a driving load part 2 for carrying out image formation, and also supplies a 5 V voltage to a microcomputer circuit part 3 and a logic circuit part 9. At the time of the power saving mode or in the case where an interlock 4 is in an open state and the driving load part 2 is in a low load or idling state, the microcomputer circuit part 3 turns off a load path switch 11 and turns on a power storage switch 10, whereby a supply voltage from the 24 V voltage supply side is supplied to a power storage device 12, thereby preventing a cross regulation. Moreover, when the 5 V voltage is stored in the power storage device 12, a power supply switch 13 is turned off, and simultaneously a power supply switch 14 is turned on, whereby a voltage supply source to the logic circuit part 9 is switched over from the switching power supply 1 to the power storage device 12. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus using electrophotography, such as a copy, a facsimile (FAX), and a printer.
[0002]
[Prior art]
Conventionally, as an image forming apparatus having a function for realizing power saving, when shifting from the driving mode during the printing process to the power saving mode in a state where the printing process is stopped, the driving power source of the laser emitting unit, charging, It is known to reduce power consumption by turning off a power supply current to a driving power supply for a high-voltage power supply for development and transfer, a photosensitive drum, a fixing unit, a paper transport system, and the like. In addition, the image forming apparatus is provided with an interlock switch that shuts off power supply to the drive unit in order to ensure user safety when the opening / closing cover of the apparatus main body is opened during printing.
[0003]
FIG. 5 is a diagram showing a configuration of a power supply circuit of a conventional image forming apparatus.
[0004]
In FIG. 5, the switching power supply 1 has a bridge diode 20, a transformer 21, diodes 22a and 22b, and load resistors 7 and 8 for rectifying an AC voltage supplied from an AC 100V power supply, and generates a 24V voltage and a 5V voltage. . In the switching power supply 1, the 24V voltage supply side supplies a voltage to the drive load unit 2 via the interlock switch 4 and the power cutoff switch 5, and the 5V voltage supply side supplies a voltage to the microcomputer circuit unit 3 and the logic circuit unit 9. Supply. The 24 V voltage supply side is connected to ground via a load resistor 7, and the 5 V voltage supply side is connected to ground via a load resistor 8.
[0005]
The drive load unit 2 includes a scanner unit 31, a paper transport unit 32 having a paper feed cassette, a paper feed roller, and the like, and an image forming unit 33 having a photosensitive drum, a developing device, a fixing device, and the like. The logic circuit unit 9 is a logic circuit in an electric component such as a control IC (Integrated Circuit) necessary for the image forming process by the drive load unit 2.
[0006]
When a cover (not shown) attached to the image forming apparatus main body is in an open state, the interlock switch 4 is turned off to cut off the power supply to the drive load unit 2, and when the cover is closed, the interlock switch 4 is turned off. It turns on, and voltage supply to the drive load unit 2 is performed. The cover open / close detection sensor 6 has two resistors connected in series, and switches between supply and cutoff of a voltage from the switching power supply 1 to the microcomputer circuit unit 3 by switching on and off of the interlock switch 4. The microcomputer circuit section 3 can detect the ON / OFF state of the interlock switch 4 based on the presence or absence of the supply voltage from the cover opening / closing detection sensor 6. The microcomputer circuit section 3 controls the supply and cutoff of the voltage to the drive load section 2 by applying a voltage to the power cutoff switch 5 in the drive mode and cutting off the voltage supply to the power cutoff switch 5 in the power saving mode.
[0007]
In the switching power supply 1, a constant current is supplied for the purpose of smoothly raising the secondary voltage (24V, 5V) at the time of power-on and for keeping the voltage within a predetermined range even in a low load or no load state. The load resistances 7 and 8 are used for consumption. For example, when the voltage supply to the power cutoff switch 5 is turned off in the power saving mode, or the interlock switch 4 is opened due to the cover being opened, the 24V voltage supply side is in a no-load state and the 5V Since the voltage supply side is in a loaded state, the voltage supplied from the 24 V voltage supply side increases to 24 V or more due to the cross regulation of the power supply. In order to suppress this voltage rise within a predetermined value, the current supplied from the 24 V voltage supply side is controlled so as to flow to the ground via the load resistor 7.
[0008]
[Problems to be solved by the invention]
In other words, in the power saving mode or when the cover is open, a large amount of current flows from the 24 V voltage supply side to the ground unnecessarily, which causes a problem that the power use efficiency and the power consumption are reduced. Was.
[0009]
The present invention has been made in order to solve the above-described problems, and has been made to improve the power use efficiency in the power saving mode or when the cover is open, and to reduce the power consumption. The purpose is to provide a device.
[0010]
[Means for Solving the Problems]
An image forming apparatus according to claim 1 of the present invention includes a driving unit for performing an image forming process, a control unit for controlling the image forming process by the driving unit, and a first voltage supplied to the driving unit. A power supply for supplying a second voltage to the control means, a cutoff means for cutting off a first voltage supplied from the power supply to the drive means, and a power supply supplied from the power supply to the drive means by the cutoff means. A power supply means for storing a first voltage, and a voltage supply source for the control means, the power supply being supplied from the power supply to the control means when the voltage of a predetermined value or more is stored in the power storage means. A switching means for switching to the means, when the image forming processing by the driving means is stopped, the first voltage by the cross regulation using the power storage means instead of the load resistance. Can perform power storage of the first voltage with suppressing boost, aims to improve power use efficiency of the entire device, it is possible to reduce power consumption.
[0011]
An image forming apparatus according to a second aspect of the present invention is the image forming apparatus according to the first aspect, wherein the switching unit is configured to supply a second voltage from the power storage unit to the control unit, If the value of the voltage stored in the power storage unit becomes smaller than a predetermined value during the supply of the second voltage to the control unit, a voltage supply source to the control unit is switched from the power storage unit to the power supply. With this configuration, the supply voltage to the control unit can be kept constant.
[0012]
An image forming apparatus according to a third aspect of the present invention is the image forming apparatus according to the first aspect, wherein the blocking unit is configured to control the driving unit in a power saving mode in which image forming processing by the driving unit is suspended. Is configured to cut off the first voltage supplied to the power supply mode, so that in the power saving mode, the first voltage can be stored while preventing the cross regulation by using the power storage unit instead of the load resistance, The power use efficiency of the entire apparatus can be improved, and the power consumption can be reduced.
[0013]
An image forming apparatus according to a fourth aspect of the present invention is the image forming apparatus according to the first aspect, further comprising an openable / closable cover that covers the apparatus main body, wherein the blocking unit is interlocked with the cover, and the cover is Since the interlock switch cuts off the first voltage supplied to the driving means when the cover is in the open state, when the cover is in the open state, cross regulation is performed using the power storage means instead of the load resistance. Thus, the first voltage can be stored, and the power use efficiency of the entire apparatus can be improved, and the power consumption can be reduced.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a digital multifunction peripheral according to an embodiment of the present invention will be described as an example of an image forming apparatus according to the present invention with reference to the drawings. FIG. 1 is a schematic side view mainly showing a mechanical configuration of a digital multifunction peripheral according to an embodiment of the present invention.
[0015]
The digital multifunction peripheral 1 includes a main body 200, a paper post-processing unit 300 disposed on the left side of the main body 200, an operation unit 400 for a user to input various operation commands and the like, and an upper part of the main body 200. , And a document feeding unit 600 disposed above the document reading unit 500.
[0016]
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, and displays various operation buttons and the like for the user to input various operation commands. A start key 402 is used by a user to input a print execution command and the like, and a ten key 403 is used by a user to input the number of prints and the like.
[0017]
The document feeding section 600 includes a document storage section 601, a document discharge section 602, a paper feed roller 603, a document transport section 604, and the like, and the document reading section 500 includes a scanner 501 and the like. The paper feed roller 603 feeds out the documents set in the document storage unit 601, and the document feed unit 604 feeds the fed documents one by one onto the scanner 501 in order. The scanner 501 sequentially reads the conveyed documents, and the read documents are discharged to a document discharge unit 602.
[0018]
The main body unit 200 includes a plurality of paper feed cassettes 201, a plurality of paper feed rollers 202, a transfer roller 203, a photosensitive drum 204, an exposure device 206, a developing device 207, a fixing roller 208, a discharge port 209, a discharge tray 210, and the like. Prepare.
[0019]
The photosensitive drum 204 is uniformly charged by a charging device (not shown) while rotating in the direction of the arrow. The exposure device 206 converts a modulation signal generated based on image data of a document read by the document reading unit 500 into a laser beam and outputs the laser beam, thereby forming an electrostatic latent image on the photosensitive drum 204. The developing device 207 supplies a black developer to the photosensitive drum 204 to form a toner image.
[0020]
On the other hand, the paper feed roller 202 pulls out the print paper from the paper feed cassette 201 in which the print paper is stored, and feeds the print paper to the transfer roller 203. The transfer roller 203 transfers the toner image on the photosensitive drum 204 to the conveyed printing paper, and the fixing roller 208 heats the transferred toner image to fix it on the printing paper. Thereafter, the printing paper is carried into the paper post-processing unit 300 from the outlet 209 of the main body 200. The printing paper is also discharged to the discharge tray 210 as needed.
[0021]
The sheet post-processing section 300 includes a carry-in port 301, a print sheet transport section 302, a carry-out port 303, a stack tray 304, and the like. The print paper transport unit 302 sequentially transports the print papers carried into the carry-in port 301 from the discharge port 209, and finally discharges the print paper from the carry-out port 303 to the stack tray 304. The stack tray 304 is configured to be able to move up and down in the direction of the arrow in accordance with the number of sheets of print paper carried out from the carry-out port 303.
[0022]
FIG. 2 is a perspective view schematically showing the appearance of the digital multifunction peripheral shown in FIG.
[0023]
The digital multifunction peripheral 100 includes a door cover 103 attached to the front surface of the main body 200 so as to be freely opened and closed. The interlock switch (blocking means) 4 is, for example, a push button switch having a projection. When the cover 103 is in the closed state, the projection is pushed in by the cover 103 to be turned on, and the cover 103 is opened. At this time, the interlock switch 4 is turned off, and the supply of voltage to the drive load unit 2 such as the laser emission unit (not shown), the developing device 207, the transfer roller 203, and the fixing roller 208 in the scanner 501 is shut off. In the present embodiment, the interlock switch 4 that is linked to the opening and closing of the cover 103 is described. However, when the developing device 207 and the photosensitive drum 204 incorporated in the apparatus main body 200 are attached and detached, a drive power supply is connected. The present invention is also applicable to an interlock switch (not shown) that shuts off the voltage supply to the power supply, and an interlock switch (not shown) that shuts off the voltage supply to the driving power supply by sliding the paper feed tray 201.
[0024]
FIG. 3 is a diagram showing a configuration of a power supply circuit of the digital multifunction peripheral shown in FIG.
[0025]
In the figure, a switching power supply 1 has a bridge diode 20, a transformer 21, diodes 22a and 22b, and load resistors 7 and 8 for rectifying an AC voltage supplied from an AC 100V power supply, and generates a 24V voltage and a 5V voltage. In the switching power supply 1, the 24V voltage supply side supplies a voltage to the drive load unit 2 via the interlock switch 4 and the power cutoff switch 5, and the 5V voltage supply side supplies a voltage to the microcomputer circuit unit 3 and the logic circuit unit 9. Supply. The 24V voltage supply side is connected to the ground via the load resistor 7 and the load path switch 11, and the 5V voltage supply side is connected to the ground via the load resistor 8.
[0026]
The drive load unit (drive unit) 2 includes a scanner unit 31, a sheet transport unit 32, and an image forming unit 33. The scanner unit 31 includes the scanner 501 and the like illustrated in FIG. 1, the paper transport unit 32 includes the sheet cassette 201 and the sheet feeding roller 202 illustrated in FIG. 1, and the image forming unit 33 includes the image forming unit 33 illustrated in FIG. An exposure device 206, a developing device 207, a transfer roller 203, a fixing roller 208, and the like are configured. Each unit operates by a voltage supply from a 24V voltage supply side, and a paper feed roller 202 conveys a print sheet to the image forming unit 33. The developing device 207 forms a toner image corresponding to the image data read by the scanner 501, the transfer roller 203 transfers the toner image to printing paper, and the fixing roller 208 fixes the toner image on printing paper to form an image. I do. The logic circuit unit (control means) 9 is a logic circuit in an electric component such as a control IC (Integrated Circuit) required for the image forming process by the drive load unit 2.
[0027]
When the cover 103 attached to the digital multifunction peripheral body 200 is open, the interlock switch 4 is turned off to cut off the power supply to the drive load unit 2. When the cover is closed, the interlock switch 4 is turned off. 4 is turned on, and power supply to the drive load unit 2 is performed. The cover open / close detection sensor 6 has two resistors connected in series, and switches between supply and cutoff of a voltage from the switching power supply 1 to the microcomputer circuit unit 3 by switching on and off of the interlock switch 4. The microcomputer circuit section 3 can detect the ON / OFF state of the interlock switch 4 based on the presence or absence of the supply voltage from the cover opening / closing detection sensor 6.
[0028]
The microcomputer circuit unit 3 includes a ROM (Read Only Memory) for storing a control program of the digital multi-function peripheral, a RAM (Random Access Memory) for temporarily storing data, a microcomputer, and the like, and controls the operation of each unit. The microcomputer circuit section 3 manages the operation mode of the apparatus main body, and supplies a voltage to the drive load section 2 by applying a voltage to the power cutoff switch (cutoff means) 5 in the drive mode during the printing operation. In the power saving mode in which the printing operation is suspended, the voltage supply to the power cutoff switch 5 is cut off, and the voltage supply to the drive load unit 2 is stopped. Here, the driving mode is a state in which an operation instruction from a user is received by the operation unit 400 and the printing process is being performed by the driving load unit 2, and the halt state of the driving load unit 2 is constant in the power saving mode. Refers to the state after the elapse of the period.
[0029]
The power storage device 12 is connected to the switching power supply 1 via the power storage switch 10, and when the power storage switch 10 is turned on, stores the supply voltage from the 24V voltage supply side. The logic circuit section 9 is connected to the 5 V voltage supply side via a power supply switch 13 and is connected to the power storage device 12 via a power supply switch 14. The power supply switch 13 is a switching element for controlling the supply and cutoff of a voltage from the 5 V voltage supply side to the logic circuit unit 9. The power supply switch 14 supplies and supplies a voltage from the power storage device 12 to the logic circuit unit 9. It is a switching element for controlling interruption.
[0030]
The operation of the image forming apparatus of the present invention will be described with reference to FIGS. FIG. 4 is a flowchart for explaining the operation of the power supply circuit shown in FIG.
[0031]
In step S1, the microcomputer circuit unit 3 determines whether the interlock switch 4 is open or the power cutoff switch 5 is off and the drive load unit 2 is in a low load or no load state. When the driving load unit 2 is in a low load or no load state, the load path switch 11 is turned off, the current path flowing from the 24 V voltage supply side to the ground via the load resistor 7 is cut off, and the power storage switch 10 is turned on. The voltage is supplied to the power storage device 12 from the 24 V voltage supply side (step S2).
[0032]
Next, the voltage stored in the power storage device 12 is monitored, and it is determined whether the voltage is 5 V or more (step S <b> 3). When it is detected that the voltage of 5 V or more is stored in the power storage device 12, the power storage is performed. The switch 10 is turned off, the power storage process by the power storage device 12 is stopped, and at the same time, the load path switch 11 is turned on to switch the load path on the 24 V voltage supply side to the ground side (step S4). Then, by turning off the power supply switch 13 and turning on the power supply switch 14, the voltage supply source to the logic circuit unit 9 is switched from the 5V voltage supply side to the power storage device 12 (step S5).
[0033]
Further, the voltage stored in the power storage device 12 is monitored, and it is determined whether or not the voltage has become less than a predetermined value (4.75 V) (step S6). Then, the power supply switch 13 is turned on and the power supply switch 14 is turned off at the same time, and the voltage supply source to the logic circuit unit 9 is returned from the power storage device 12 to the 5 V voltage supply side of the switching power supply 1 (step S7).
[0034]
According to the digital multifunction peripheral 100 having the power supply circuit configured as described above, in the power saving mode or when the interlock switch 4 is in the open state and the driving load unit 2 is in the no-load state, 24 V due to the cross regulation is used. In order to prevent the voltage from being excessively boosted, the supply voltage from the 24 V voltage supply side is stored in the power storage device 12, and when the 5 V voltage is stored in the power storage device 12, the voltage stored in the power storage device 12 is used as a logic circuit unit. 9, the power use efficiency of the entire apparatus can be improved, and the power consumption can be reduced. Further, when the voltage stored in the power storage device 12 becomes lower than a predetermined value, the voltage supply source to the logic circuit unit 9 is switched from the power storage device 12 to the switching power supply 1. The supply voltage can be kept constant.
[0035]
【The invention's effect】
As described above, according to the present invention, it is possible to improve the power use efficiency in the power saving mode or when the cover of the apparatus main body is in the open state, and to reduce the power consumption.
[Brief description of the drawings]
FIG. 1 is a schematic side view mainly showing a mechanical configuration of a digital multifunction peripheral according to an embodiment of the present invention.
FIG. 2 is a perspective view schematically showing an appearance of the digital multifunction peripheral shown in FIG.
FIG. 3 is a diagram illustrating a configuration of a power supply circuit of the digital multifunction peripheral illustrated in FIG. 1;
FIG. 4 is a flowchart for explaining an operation of the power supply circuit shown in FIG. 3;
FIG. 5 is a diagram illustrating a configuration of a power supply circuit of a conventional image forming apparatus.
[Explanation of symbols]
REFERENCE SIGNS LIST 100 Digital multifunction device 1 Switching power supply 2 Drive load unit 3 Microcomputer circuit unit 4 Interlock switch 5 Power cutoff switch 6 Cover open / close detection sensor 7, 8 Load resistor 9 Logic circuit unit 10 Power storage switch 11 Load path switch 12 Power storage devices 13, 14 Power supply switch

Claims (4)

Driving means for performing image forming processing;
Control means for controlling an image forming process by the driving means,
A power supply that supplies a first voltage to the driving means and supplies a second voltage to the control means;
Blocking means for blocking a first voltage supplied from the power supply to the driving means;
Power storage means for storing the first voltage when the first voltage supplied from the power supply to the drive means is cut off by the cutoff means;
An image forming apparatus comprising: a switching unit that switches a voltage supply source to the control unit from the power supply to the power storage unit when a voltage equal to or higher than a predetermined value is stored in the power storage unit. The image forming apparatus according to claim 1,
The switching means,
A second voltage is supplied from the power storage unit to the control unit, and a value of a voltage stored in the power storage unit becomes less than a predetermined value while the power storage unit supplies the second voltage to the control unit. In this case, an image forming apparatus switches a voltage supply source to the control unit from the power storage unit to the power supply. The image forming apparatus according to claim 1,
The image forming apparatus according to claim 1, wherein the interrupting unit interrupts the first voltage supplied to the driving unit in a power saving mode in which the image forming process by the driving unit is suspended. The image forming apparatus according to claim 1,
Equipped with an openable / closable cover that covers the device body,
The image forming apparatus according to claim 1, wherein the interrupting unit is an interlock switch that interlocks with the cover and shuts off a first voltage supplied to the driving unit when the cover is open.

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