JP2004248478A - Electric driving equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the deterioration or puncture of a circuit element on a control circuit that may be caused to occur by a current that flows even in a stand-by state, and to cut power consumption dependably. <P>SOLUTION: In an image-forming apparatus that operates on the supply of at least two different power source voltages for a drive system and a control system, a high-voltage power supply unit 201 receives the drive system voltage to operate according to a control signal. A CPU 202 operates on the control system voltage, outputs a control signal to the high-voltage power supply unit 201 and controls the operations of the power supply unit 201 by outputting the control signal to the power supply unit 201. In supplying or interrupting the drive system power to the power supply unit 201 by a relay 203, a voltage level of the control signal is caused to change to a ground level when the relay 203 interrupts the supply of the drive system voltage. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric drive device, and more particularly to an electric drive device that operates by receiving at least two types of power supply voltages, a drive system and a control system.
[0002]
The electric drive device is, for example, an image forming apparatus, and is an apparatus for reducing power consumption during standby.
[0003]
[Prior art]
In recent years, there has been a strong demand for energy saving for electrophotographic image forming apparatuses such as facsimile apparatuses, copying apparatuses, and printers, and in particular, to reduce the power consumption of image forming apparatuses in standby states other than during image forming operations. Is required.
[0004]
Therefore, conventionally, in an image forming apparatus, only a unit that needs to operate even in a standby state, for example, a unit that supplies power to only a control unit even in a standby state and needs to operate only during other image forming operations Power supply to the image forming apparatus, thereby reducing the power consumption of the entire image forming apparatus.
[0005]
The units of the image forming apparatus that need to be operated only during the image forming operation include, for example, a process voltage power supply unit, a paper transport unit, an image forming unit, and the like. Switching is performed using switching means.
[0006]
In most cases, the voltage supplied to the process voltage power supply unit, the paper transport unit, the image forming unit, and the like include a control voltage set to a relatively low voltage for controlling each unit, and an actual voltage. There are at least two systems of power supply voltages required to perform the operation, and a relatively high drive voltage. Usually, the supply of the power supply of the drive voltage system which is more effective by power saving is cut off in a standby state. That is being done.
[0007]
[Problems to be solved by the invention]
However, in the conventional power saving method of interrupting the supply of the drive voltage system power among the control voltage and the drive voltage in the standby state as described above and continuing the supply of the control voltage system power, the control voltage is not applied. As a result, there is a possibility that circuit elements may be degraded or destroyed in a control circuit portion in which a control signal current constantly flows.
[0008]
The present invention has been made in view of such a problem, and it is possible to prevent deterioration and destruction of a circuit element of a control circuit which may occur due to current flowing even in a standby state, and to reliably save power. It is an object of the present invention to provide an electric drive device capable of performing the following.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, in an electric drive device that operates by receiving at least two types of power supply voltages, a drive system and a control system, And a control unit that operates using the control system voltage as a power source, outputs a control signal to the drive unit to control the operation of the drive unit, and supplies the drive system voltage to the drive unit or Switching means for interrupting, and control means provided in the control unit for changing a voltage level of the control signal to a ground level when supply of the drive system voltage to the drive unit is interrupted by the switching means. And an electric drive device characterized by having the following.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0011]
[First Embodiment]
FIG. 1 is a diagram showing a schematic configuration of a first embodiment of an image forming apparatus according to the present invention. This image forming apparatus is a laser beam printer using an electrophotographic process.
[0012]
In the figure, reference numeral 101 denotes a laser beam printer main body (hereinafter, referred to as “main body”), and the main body 101 includes a cassette 102 for storing recording paper S. The cassette 102 includes a cassette presence / absence sensor 103 for detecting the presence / absence of the recording paper S in the cassette 102, and a cassette size sensor 104 for detecting the size of the recording paper S in the cassette 102 (comprising a plurality of micro switches). ), A paper feed roller 105a for feeding out the recording paper S from the cassette 102, a pair of transport rollers 105b, 105c, 105d, and the like. A registration roller pair 106 for synchronously transporting the recording paper S is provided downstream of the paper feed roller 105a and the transport roller pairs 105b, 105c, and 105d. Further, downstream of the registration roller pair 106, the leading and trailing ends of the recording paper S are detected, and recording is performed based on a paper feed sensor 124 for generating an image writing timing signal and a laser beam 118 from the laser scanner unit 107. A process cartridge 108 for forming a toner image on the paper S is provided. Further, a fixing unit 109 for thermally fixing the toner image formed on the recording paper S is provided downstream of the process cartridge 108, and a downstream of a heat fixing unit in the fixing unit 109 is provided with a paper discharge unit. A paper discharge sensor 110 for detecting the conveyance state, a conveyance roller pair 111 for conveying the recording paper S, a face-up discharge roller pair 140 for discharging the recording paper S, and a loading tray 112 for loading the recording paper S on which recording has been completed. Is provided.
[0013]
The paper ejection sensor 110 is provided inside the fixing device 110, and detects a timing at which the recording paper S has passed through the heat fixing unit. After passing through the transport roller pair 111, the recording paper S is discharged to the stack tray 112 via the face-up discharge roller pair 140. The full load detection sensor 142 provided in the paper discharge unit is a sensor that detects whether the recording paper S on the stack tray 112 is full and detects the movement of the recording paper S in the paper discharge unit.
[0014]
The laser scanner unit 107 emits a laser beam that is modulated based on an image signal (image signal VDO) sent from an external device described later, and outputs the laser beam from the laser unit 113 to be described later. It comprises a polygon mirror 114 for scanning on the photosensitive drum 117, an imaging lens 115, a return mirror 116, and the like.
[0015]
The process cartridge 108 performs a known electrophotographic process, and includes a photosensitive drum 117, a primary charging roller 119, a developing device 120, a transfer charging roller 121, a cleaner 122, and the like. The fixing unit 109 includes a fixing film 109a, a pressure roller 109b, a ceramic heater 109c provided inside the fixing film 109a, and a thermistor 109d for detecting a surface temperature of the ceramic heater 109c.
[0016]
Reference numeral 123 denotes a main motor, which applies a driving force to the paper feed roller 105a through a paper feed roller clutch 125, and applies a registration roller pair to the transport roller pairs 105b, 105c, 105d and the registration roller pair 106. Driving force is applied via the clutch 129, and further, driving units are also applied to each unit of the process cartridge 108 including the photosensitive drum 117, the fixing device 109, the conveying roller pair 111, and the face-up discharge roller pair 140. .
[0017]
Reference numeral 126 denotes an engine controller which controls the electrophotographic process by the laser scanner unit 107, the process cartridge 108, and the fixing unit 109, and controls the conveyance of the recording paper S in the main body 101.
[0018]
A video controller 127 is connected to an external device 131 such as a personal computer by a general-purpose interface 130 (Centronics, RS232C, USB, etc.), and expands image information sent from the general-purpose interface 130 into bit data. Then, the bit data is sent to the engine controller 126 as a / VDO signal.
[0019]
A line 128 connecting the engine controller 126 and the video controller 127 is composed of a command / status signal line, a clock signal line, a / VDO signal line, a synchronization signal line, and the like between the two controllers.
[0020]
The engine controller 126 starts a printing operation by receiving a printing operation start command from the video controller 127, starts driving the main motor 123, starts up the ceramic heater 109c, and starts driving the polygon mirror 114.
[0021]
By driving the main motor 123, the photosensitive drum 117 and the transfer roller 121, the fixing film 109a and the pressure roller 109b of the fixing device 109, the transport roller pair 111, and the face-up paper discharge roller pair 140 start rotating.
[0022]
Thereafter, the engine controller 126 starts controlling the amount of light of the laser unit 113 and sequentially drives the primary charging roller 119, the developing device 120, and the transfer charging roller 121 at a high voltage.
[0023]
In the engine controller 126, an internal CPU (not shown) detects a pulse interval based on a / BD signal sent from a laser light detection sensor (not shown), and the rotation of the polygon mirror 114 is determined based on the pulse interval. Detects the steady state. When it is detected that the rotation of the polygon mirror 114 has reached a steady state, the paper feed roller clutch 125 is turned on to drive the paper feed roller 105a, whereby the recording paper S in the paper feed cassette 102 is fed out. It is. The feed roller clutch 125 is immediately turned off when one sheet of recording paper S is fed from the cassette 102. The registration roller clutch 129 is turned on together with the sheet supply roller clutch 125, whereby the conveyance roller pairs 105b, 105c, 105d and the registration roller pair 106 rotate, and the fed recording paper S is conveyed to the conveyance roller pairs 105b, 105c, 105d. And is conveyed toward the registration roller pair 106 via the. The CPU of the engine controller 126 detects that the recording paper S has reached the paper feed sensor 124, starts outputting a synchronization signal to the video controller 127, and turns off the registration roller clutch 129 to convey the recording paper S. The driving of the roller pairs 105b, 105c, 105d and the registration roller pair 106 is temporarily stopped.
[0024]
At this time, the video controller 127 has started to develop the image information into a dot image, and has completed the preparation for outputting the / VDO signal. Upon receiving the synchronization signal from the engine controller 126, the video controller 127 starts outputting the / VDO signal as one page of image data.
[0025]
On the other hand, the engine controller 126 turns on the registration roller clutch 129 at the same time as the start of the output of the synchronization signal, and drives the conveyance roller pairs 105b, 105c, 105d and the registration roller pair 106. The conveyance roller pairs 105b, 105c, 105d and the registration roller pair 106 are driven until the trailing edge of the recording sheet S passes through the registration roller 106. During this time, the engine controller 126 drives the laser unit 113 according to the / VDO signal from the video controller 127. The laser beam 118 emitted from the laser unit 113 is converted into a linear scan by the rotation of the polygon mirror 114 of the laser scanner unit 107, and is irradiated on the photosensitive drum 117 by the imaging lens 115 and the return mirror 116.
[0026]
The photosensitive drum 117 is rotationally driven at a predetermined peripheral speed (process speed) in a clockwise direction in FIG. The photosensitive drum 117 is uniformly charged to a predetermined polarity and potential by the primary charging roller 119 during the rotation process. Scanning exposure is performed on the uniformly charged surface of the photosensitive drum 117 by a laser beam output from the laser scanner unit 107, and an electrostatic latent image of image information is formed on the surface of the photosensitive drum 117. This laser beam is subjected to modulation control (ON / OFF control) according to a time-series electric digital pixel signal of image information. The electrostatic latent image formed on the photosensitive drum 117 is developed by a developing material (toner) in the developing device 120 and is visualized.
[0027]
The recording paper S is fed by a pair of transport rollers 105b, 105c, 105d and a pair of registration rollers 106 to a transfer nip portion, which is a pressure contact portion between the photosensitive drum 117 and the transfer roller 121, at a predetermined control timing. The toner image on the surface of the photosensitive drum 117 is sequentially transferred to the surface of S. The recording paper S that has exited the transfer nip is sequentially separated from the surface of the photosensitive drum 117 in the course of rotation, and is introduced into a fixing device 109 for fixing a toner image. The heat of the ceramic heater 109c is applied to the recording paper S passing between the fixing film 109a and the pressure roller 109b via the fixing film 109a, and the pressure is applied by the pressure roller 109b. The toner image is heat-fixed. The recording paper S that has exited the fixing device 109 is sent to the stack tray 112 by a pair of conveying rollers 111 and a pair of face-up discharge rollers 140.
[0028]
After the recording paper S is separated, the photosensitive drum 117 is cleaned by the cleaner 122 to remove adhering contaminants such as untransferred toner, and is repeatedly subjected to electrophotographic image formation starting from charging. You.
[0029]
Next, a description will be given of the interruption of the driving power supply voltage of the high-voltage power supply unit for power saving.
[0030]
The main body 101 has three states: a print mode for executing printing, a standby mode for waiting at any time for printing, and a sleep mode for standby with minimum power consumption. In the sleep mode, in order to reduce the power consumption of the main body 101, the power supply to a unit other than the unit which always needs the power supply, such as a CPU, is shut off.
[0031]
FIG. 2 is a block diagram illustrating a high-voltage power supply unit that supplies a high voltage to each of the primary charging roller 119, the developing device 120, and the transfer charging roller 121, and a CPU that controls a supply operation of the high-voltage power supply unit.
[0032]
In the figure, reference numeral 201 denotes a high-voltage power supply unit, which includes a control circuit 201a and a high-voltage generation unit 201b. A drive system voltage of 24 V is supplied to the control circuit 201a and the high-voltage generation unit 201b via a relay 203. The high voltage generation unit 201b supplies a high voltage to the primary charging roller 119, the developing device 120, and the transfer charging roller 121, respectively. Reference numeral 202 denotes a CPU to which a 3.3 V control system voltage is constantly supplied. The relay 203 opens and closes according to a relay control signal sent from the CPU 202 to supply or cut off the drive system voltage to the high voltage power supply unit 201. The CPU 202 outputs a relay control signal to the relay 203, and also outputs a plurality of high-voltage clock signals and a plurality of high-voltage output permission signals to the control circuit 201a.
[0033]
The control circuit 201a controls the high voltage generation unit 205 based on a plurality of high voltage clock signals and a plurality of high voltage output permission signals output from the CPU 202, and generates a primary charging voltage, a development voltage, and a transfer voltage in the high voltage generation unit 205. Let it. The high voltage output enable signal is at a high level in the print mode, that is, when the primary charging voltage, the developing voltage, and the transfer voltage are to be generated, and in the other standby mode and the sleep mode, that is, the primary charging voltage. When the voltage, the developing voltage, and the transfer voltage should not be generated, they are at the Gnd level (ground level). The high-voltage clock signal is a clock generator output inside the CPU 202, and is output from the CPU 202 as a clock pulse having a cycle corresponding to the set value of the CPU internal register, and is always output in the print mode and the standby mode. You.
[0034]
When the relay control signal supplied from the CPU 202 to the relay 203 is at a high level, a 24 V voltage is supplied to the high voltage power supply unit 201, and when the relay control signal is at a Gnd level, the supply is cut off.
[0035]
FIG. 3 is a timing chart showing signal waveforms of a relay control signal, a high voltage clock signal, and a high voltage output permission signal. This timing chart shows the waveform of each signal when the image forming apparatus shifts from the standby mode to the sleep mode and when the image forming apparatus returns from the sleep mode to the standby mode.
[0036]
When receiving an instruction to shift to the sleep mode from the video controller 127, the CPU 202 lowers the relay control signal to the Gnd level as shown in FIG. 3 to reduce power consumption. Thereby, the relay 203 is turned off, and the 24V voltage supplied to the high voltage power supply unit 201 is cut off. At the same time, the CPU 202 drops the high voltage clock signal to the Gnd level. The CPU 202 lowers the high voltage clock signal to the Gnd level by switching the output port of the high voltage clock signal from the clock generator output to the normal I / O port output. In addition, the high voltage output permission signal remains at the Gnd level in the standby mode and the sleep mode and does not change as described above.
[0037]
As described above, when the supply of the 24V voltage to the high-voltage power supply unit 201 is interrupted, all control signals (high-voltage clock signal and high-voltage output permission signal) supplied from the CPU 202 to the control circuit 201a are at the Gnd level. Therefore, the output part of the CPU 202 and the input part of the control circuit 201a are in a non-operating state, and deterioration and destruction of each circuit element constituting the output part of the CPU 202 and the input part of the control circuit 201a can be prevented.
[0038]
Next, the case of returning from the sleep mode to the standby mode will be described.
[0039]
When receiving an instruction to shift to the standby mode from the video controller 127, the CPU 202 raises the relay control signal to a high level as shown in FIG. Let it be supplied. At the same time, the high voltage clock signal is raised from the Gnd level to the high level, that is, the output is switched from the I / O port output to the clock generator output to output the high voltage clock signal, and waits to be able to shift to the print mode at any time.
[0040]
In the above-described first embodiment, the high-voltage power supply unit inside the image forming apparatus main body is described as an example, but the present invention can be applied to other driving units inside the image forming apparatus main body. The present invention is also applicable to an optional unit connected to the outside of the image forming apparatus main body.
[0041]
[Second embodiment]
Next, a second embodiment will be described.
[0042]
The configuration of the second embodiment is basically the same as the configuration of the first embodiment.
Therefore, in the description of the second embodiment, the configuration of the first embodiment is used, the same components are denoted by the same reference numerals, and the description thereof will be omitted, and only different portions will be described. I do.
[0043]
In the second embodiment, a description will be given of a drive power supply voltage interruption in a case where the drive unit to be subjected to power saving is the main motor 123.
[0044]
Also in the second embodiment, the main body 101 has three modes: a print mode for executing printing, a standby mode for waiting for printing at any time, and a sleep mode for standby with minimum power consumption. There are two states. In the sleep mode, in order to reduce the power consumption of the main body 101, the power supply to a unit other than the unit which always needs the power supply, such as a CPU, is shut off.
[0045]
FIG. 4 is a block diagram showing a main motor 123 as a drive unit and a CPU for controlling the operation of the main motor 123.
[0046]
As shown in FIG. 4, the main motor 123 includes a driving unit 123a including a motor itself, a control circuit 123b for controlling the start, rotation speed, and stop of the driving unit 123a, It comprises a control power generation circuit 123c for supplying to 123b. A drive system voltage of 24 V is supplied to the drive unit 123a and the control power generation circuit 123c via the relay 403.
[0047]
Reference numeral 401 denotes a CPU to which a control system voltage of 3.3 V is constantly supplied. The relay 402 opens and closes according to a relay control signal sent from the CPU 401 to supply or cut off the drive system voltage to the main motor 123. The CPU 401 outputs a relay control signal to the relay 402, and also outputs a / acceleration signal and a / deceleration signal to the control circuit 123b.
[0048]
The control circuit 123b of the main motor 123 sends a pulse signal indicating the rotation state of the drive unit 123a to the CPU 401, and performs the rotational acceleration and deceleration of the drive unit 123a based on the / acceleration signal and / deceleration signal output from the CPU 401. . Specifically, when the / acceleration signal is set to the high level and the / deceleration signal is set to the Gnd level, the drive unit 123a performs the deceleration operation, and conversely, the / deceleration signal is set to the high level and the / acceleration signal is set. When the signal is set to the Gnd level, an acceleration operation is performed.
[0049]
In the print mode, the CPU 401 sets the / deceleration signal to high level and lowers the / acceleration signal to Gnd level, thereby starting rotation of the driving unit 123a. The CPU 401 monitors a pulse signal whose frequency changes in accordance with the rotation speed of the driving unit 123a, and when the rotation of the driving unit 123a is faster than a predetermined target rotation speed, sets the / acceleration signal to a high level, The / deceleration signal is lowered to the Gnd level to perform the deceleration operation of the rotation of the drive unit 123a. Conversely, when the speed is lower than a predetermined target rotation speed, the / deceleration signal is set to a high level, and the / acceleration signal is set to the Gnd level. The acceleration operation is performed by dropping the drive unit 123a, whereby the rotation of the driving unit 123a is maintained at a predetermined target rotation speed. Therefore, in the print mode, that is, during the rotation operation of the main motor 123, both the / acceleration signal and the / deceleration signal repeat the high level and the Gnd level, respectively, according to the rotation state.
[0050]
Next, in the standby mode, the CPU 401 sets the / acceleration signal to the high level and the / deceleration signal to the Gnd level and outputs the signal to the control circuit 123b in order to surely stop the rotation of the driving unit 123a. I do. In the standby mode, the CPU 401 outputs a high-level relay control signal to the relay 402, whereby the main motor 123 is supplied with a 24V power supply voltage.
[0051]
FIG. 5 is a timing chart showing signal waveforms of the relay control signal, the / acceleration signal, and the / deceleration signal. This timing chart shows the waveform of each signal when the image forming apparatus shifts from the standby mode to the sleep mode and when the image forming apparatus returns from the sleep mode to the standby mode.
[0052]
When receiving an instruction to shift to the sleep mode from the video controller 127, the CPU 401 lowers the relay control signal to the Gnd level as shown in FIG. 5 in order to reduce power consumption. As a result, the relay 402 is turned off, and the 24V power supply voltage supplied to the main motor 123 is cut off. At the same time, the CPU 401 lowers the / acceleration signal to the Gnd level.
[0053]
If the / acceleration signal is dropped to the Gnd level before the relay 402 is turned off, the drive unit 123a of the main motor 123 rotates until the 24V power supply voltage is cut off. When the / acceleration signal is dropped to the Gnd level after the relay 402 is turned off, the high level / acceleration signal is supplied from the power supply during the period from when the relay 402 is turned off to when the / acceleration signal becomes the Gnd level. If the period is momentary, there is a risk that the output unit of the CPU 401 and the input unit of the control circuit 123b may be damaged. In order to prevent such a situation, in the present embodiment, the / acceleration signal is dropped to the Gnd level at the same time as the relay 402 is turned off.
[0054]
Thus, when the 24V power supply voltage to the main motor 123 is cut off, all control signals (/ acceleration signal // deceleration signal) supplied from the CPU 401 to the control circuit 123b become Gnd level, and the CPU 401 output unit and the control circuit 123b Of the input unit can be prevented from being degraded or destroyed.
[0055]
Next, the case of returning from the sleep mode to the standby mode will be described.
[0056]
When receiving an instruction to shift to the standby mode from the video controller 127, the CPU 401 raises the relay control signal to a high level and outputs it to the relay 402 to turn on the relay 402, as shown in FIG. , / Acceleration signal is switched from the Gnd level to the high level and output to the control circuit 123b, and the apparatus waits at any time to shift to the print mode.
[0057]
Also in this case, if the / acceleration signal is raised to a high level before the relay 402 is turned on, a high level / acceleration signal is output to the control circuit 123b to which power is not supplied. Even if this output state is instantaneous, there is a risk of damaging the output section of the CPU 401 and the input section of the control circuit 123b. Also, if the / acceleration signal is raised to a high level after the relay 402 is turned on, the main motor 123 will rotate during the period from when the relay 402 is turned on until the / acceleration signal goes to a high level. To prevent this, in the present embodiment, the / acceleration signal is raised to a high level at the same time as the relay 402 is turned on.
[0058]
In the second embodiment, the case where the present invention is applied to the main motor unit inside the image forming apparatus main body is described as an example. However, the present invention is applied to another drive unit inside the image forming apparatus main body. May be applied. Further, the present invention may be applied to an optional unit connected to the outside of the image forming apparatus main body.
[0059]
[Third Embodiment]
Next, a third embodiment will be described.
[0060]
The configuration of the third embodiment is basically the same as the configuration of the second embodiment.
Therefore, in the description of the third embodiment, the configuration of the second embodiment is used, the same components are denoted by the same reference numerals, and the description thereof will be omitted, and only different portions will be described. I do.
[0061]
FIG. 6 is a block diagram illustrating the main motor 123 and the CPU 401 according to the third embodiment.
[0062]
In the third embodiment, a capacitor 403 is connected to a power input terminal of the main motor 123 in order to stabilize a 24V power supply voltage supplied to the main motor 123. Further, in the third embodiment, it is assumed that there is a delay in the rotation start timing of the drive unit 123a of the main motor 123, and the / acceleration signal is set to a high / It is assumed that a time Tstart is required from a point in time when the driving unit 123a starts rotating to a point in time when the driving unit 123a actually starts to rotate from the level (the driving unit 123a does not rotate) to the Gnd level. Further, when the supply of the 24 V power supply voltage to the main motor 123 is changed from cutoff (the drive unit 123a does not rotate) to supply in a state where the / acceleration signal is at the Gnd level, the drive unit 123a actually It is also assumed that a time Tstart is required before the start.
[0063]
FIG. 7 is a timing chart showing signal waveforms of a relay control signal, a 24V power supply (power supply voltage actually supplied to the main motor 123), an / acceleration signal, and a / deceleration signal in the third embodiment. This timing chart shows the waveform of each signal when the image forming apparatus shifts from the standby mode to the sleep mode and when the image forming apparatus returns from the sleep mode to the standby mode.
[0064]
Upon receiving an instruction to shift to the sleep mode from the video controller 127, the CPU 401 lowers the / acceleration signal to the Gnd level as shown in FIG. 7, and changes the relay control signal to the Gnd level to reduce power consumption. The level is lowered to a level, and the relay 402 is turned off. Even when the relay 402 is turned off, the power supply voltage supplied to the main motor 123 is kept at 24 V for the discharging time of the capacitor 403 by the action of the capacitor 403. Accordingly, as shown in FIGS. 7B and 7C, the power supply voltage supplied to the main motor 123 drops from 24 V to the Gnd level after the time Toff has elapsed after the / acceleration signal has dropped to the Gnd level. here,
Tstart ≧ Toff
Are set such that the following relationship is satisfied. As a result, 24 V power supply to the main motor 123 is cut off before the driving section 123a actually starts rotating, and the rotation of the driving section 123a in the sleep mode is prevented.
[0065]
Thus, in the sleep mode, all control signals (/ acceleration signal // deceleration signal) supplied from the CPU 401 to the control circuit 123b become Gnd level, and the output section of the CPU 401 and the input section of the control circuit 123b are deteriorated or destroyed. Can be prevented.
[0066]
Next, the case of returning from the sleep mode to the standby mode will be described.
[0067]
Upon receiving the instruction to shift to the standby mode from the video controller 127, the CPU 401 raises the relay control signal to a high level to turn on the relay 402, as shown in FIG. When the relay 402 is turned on, the capacitor 403 is charged. After a lapse of the charging period, the power supply voltage supplied to the main motor 123 rises to 24 V as shown in FIG. At this time, if the / acceleration signal remains at the Gnd level, the driving unit 123a starts rotating in spite of the standby mode. Wait to be able to enter mode. As shown in FIGS. 7B and 7C, even after the power supply voltage supplied to the main motor 123 rises to 24 V and the / acceleration signal rises to a high level after a time Ton,
Tstart ≧ Ton
Is satisfied, the / acceleration signal becomes a high level before the driving section 123a starts rotating, and the rotation of the driving section 123a can be prevented.
[0068]
Also in the third embodiment, the case where the present invention is applied to the main motor unit inside the image forming apparatus main body is described as an example, but the present invention is applied to another drive unit inside the image forming apparatus main body. May be applied. Further, the present invention may be applied to an optional unit connected to the outside of the image forming apparatus main body.
[0069]
As described above, various embodiments of the present invention have been shown and described. Examples of the embodiments of the present invention are listed below.
[0070]
[Embodiment 1] In an electric drive device that operates by receiving at least two types of power supply voltages of a drive system and a control system,
A drive unit that receives the drive system voltage and operates according to a control signal;
A control unit that operates using the control system voltage as a power supply, and outputs a control signal to the drive unit to control the operation of the drive unit;
Switching means for supplying or cutting off the drive system voltage to the drive unit,
A control unit provided in the control unit for changing a voltage level of the control signal to a ground level when the supply of the drive system voltage to the drive unit is interrupted by the switching unit. And electric drive equipment.
[0071]
[Embodiment 2] The drive unit is a device that drives when a control signal output from the control unit is at a ground level,
The control means controls the timing of changing the voltage level of the control signal to a ground level when the supply of the drive system voltage to the drive unit is cut off by the switching means. 3. The electric drive device according to claim 1, wherein the timing is the same as the timing of the operation.
[0072]
[Embodiment 3] The drive unit recognizes a drive command when the control signal output from the control unit is at the ground level, and the supply of the drive system voltage is actually performed, A device that is actually driven after a lapse of a first predetermined time after the recognition,
The control unit is configured to switch off the supply of the drive system voltage to the drive unit by the switching unit and to cut off the voltage supplied to the drive unit by the first predetermined time from the time when the voltage is actually cut off. 3. The electric drive device according to claim 2, wherein the voltage level of the control signal is changed to the ground level before a second time below.
[0073]
[Embodiment 4] When the supply of the drive system voltage to the drive unit is restarted by the switching means, the control unit changes the voltage level of the control signal from the ground level to the drive system to the drive unit. The electric drive device according to any one of the first to third embodiments, wherein the voltage is changed to the voltage level of the control signal before the supply of the voltage is cut off.
[0074]
[Embodiment 5] When the supply of the drive system voltage to the drive unit is restarted by the switching means, the control means changes the voltage level of the control signal to the voltage level of the control signal before the supply is cut off. The electric drive device according to the fourth embodiment, wherein the change timing is matched with the timing at which the supply is restarted by the switching means.
[0075]
[Sixth Embodiment] The drive unit recognizes a drive command when a control signal output from the control unit is at a ground level, and the supply of the drive system voltage is actually performed, A device that is actually driven after a lapse of a first predetermined time after the recognition,
The control unit controls the first predetermined time from the point in time when the supply of the drive system voltage to the drive unit is restarted by the switching unit and the voltage supplied to the drive unit actually becomes the drive system voltage. The electric drive device according to claim 4, wherein a voltage level of the control signal is changed to a voltage level of the control signal before the supply is cut off before a third time below.
[0076]
[Embodiment 7] The electric drive device according to any one of Embodiments 1 to 6, wherein the electric drive device is an image forming apparatus.
[0077]
[Eighth Embodiment] The electric driving apparatus according to the seventh embodiment, wherein the driving unit is an external unit connected to the image forming apparatus.
[0078]
【The invention's effect】
As described above in detail, according to the present invention, in an electric drive device that operates by receiving at least two types of power supply voltages of a drive system and a control system, a drive unit receives the drive system voltage, The control unit operates according to a control signal, the control unit operates using the control system voltage as a power supply, outputs a control signal to the drive unit to control the operation of the drive unit, and a switching unit drives the drive system voltage to drive the drive system voltage. In the case where the supply to the unit is interrupted, when the supply of the drive system voltage to the drive unit is interrupted by the switching means, the voltage level of the control signal is changed to a ground level.
[0079]
As a result, deterioration and destruction of circuit elements of the control circuit, which may occur due to current flowing even in the standby state, are prevented, and power saving can be reliably performed.
[0080]
Specifically, in an electric drive device such as an image forming apparatus having at least two types of power supply voltages of a drive system and a control system, a standby state such as a sleep mode is entered, and for example, a process voltage power supply unit, conveyance of paper, etc. Even if the power supply to the system unit, the image forming unit, the external option unit, and the like is cut off by a switching means such as a relay, there is no problem such as element deterioration or destruction, and power can be reliably saved.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a schematic configuration of a first embodiment of an image forming apparatus according to the present invention.
FIG. 2 is a block diagram illustrating a high-voltage power supply unit that supplies a high voltage to each of a primary charging roller, a developing device, and a transfer charging roller, and a CPU that controls a supply operation of the high-voltage power supply unit.
FIG. 3 is a timing chart showing signal waveforms of a relay control signal, a high voltage clock signal, and a high voltage output permission signal.
FIG. 4 is a block diagram illustrating a main motor that is a drive unit and a CPU that controls the operation of the main motor.
FIG. 5 is a timing chart showing signal waveforms of a relay control signal, an / acceleration signal, and a / deceleration signal.
FIG. 6 is a block diagram illustrating a main motor and a CPU according to a third embodiment.
FIG. 7 is a timing chart showing signal waveforms of a relay control signal, a 24V power supply, a / acceleration signal, and a / deceleration signal in the third embodiment.
[Explanation of symbols]
101 Image forming apparatus (electric drive device)
107 Laser Scanner
108 Process cartridge unit
109 fuser
109c ceramic heater
112 loading tray
117 Photosensitive drum
119 Primary charging roller
120 developer
121 transfer charging roller
122 Cleaner
123 Main motor
126 Engine controller
127 Video Controller
201 High voltage power supply unit (drive unit)
201a control circuit
201b High voltage generator
202 CPU (control unit, control means)
203 relay (switching means)

Claims (1)

In an electric drive device that operates by receiving at least two types of power supply voltages of a drive system and a control system,
A drive unit that receives the drive system voltage and operates according to a control signal;
A control unit that operates using the control system voltage as a power supply, and outputs a control signal to the drive unit to control the operation of the drive unit;
Switching means for supplying or cutting off the drive system voltage to the drive unit,
A control unit provided in the control unit for changing a voltage level of the control signal to a ground level when the supply of the drive system voltage to the drive unit is interrupted by the switching unit. And electric drive equipment.

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