JP2002014574A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of shortening a transit period of time (starting time) from the first state (standby state) to the second state (state for starting image formation), and saving the energy consumption, regardless of electric power capacity restriction of the power source line. SOLUTION: In this image forming device 8 that the power consumption thereof increases at the transit period from the first state to the second state, the device is provided with plural energy feeding means 1 and 3 for feeding the electric power in the transit time period.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrophotographic process or the like.

[0002]

2. Description of the Related Art In recent years, image forming apparatuses such as copiers, printers, and facsimile machines using an electrophotographic process have recently been used for reasons such as that the image is beautiful and that the image after fixing on paper is stable. Widely used in offices.

[0003] Such an image forming apparatus is often used with its power turned on in general because of the nature of its product. Due to recent global environmental problems, reduction of the power consumption of such an image forming apparatus is required. It has become a challenge.

Since such an image forming apparatus generally uses an electrophotographic process, a heat fixing device for melting a toner image by heat and fixing it on a recording medium such as a recording paper or an OHP sheet is provided. Much of the energy of the forming device is consumed by the fixing device.

Therefore, it is important to reduce the energy consumption of the fixing device. Conventionally, when the image forming apparatus is not used, that is, in a standby state, a device having a mode for lowering the temperature of the fixing device and saving power is widely used at present. Have been done.

On the other hand, the first copy time (Fir
(StCopyTime: hereinafter abbreviated as FCOT) and a device having a short first print time are required. However, usually, the reduction of this time requires a lot of energy at the time of preheating the heating roller and at the time of starting up the fixing device.
This is contrary to the demand for energy conservation.

Therefore, each company has made various proposals as countermeasures.

For example, by reducing the thickness of the heating roller and reducing the heat capacity of the roller, it is possible to shorten the time required for starting up to the fixing temperature and save energy.

[0009] In Japanese Patent Application Laid-Open No. 9-185299, about 15 energy savings are cited as conventional examples. In Japanese Patent Application Laid-Open No. 9-185299, as an energy saving technique effective for these conventional examples, a fixing unit temperature is detected in a power saving mode, and the fixing unit temperature falls below a predetermined value and a recovery time is set. When the length becomes longer, other units such as an image processing unit are also set to the power saving mode and the power supply is stopped to save energy. According to this, even when power supply to the image processing unit or the like is stopped, the image processing unit reads data by effectively utilizing the time until the fixing device reaches the fixing temperature at startup. Since the operation can be completed, energy saving can be realized without affecting FCOT.

[0010]

However, in the image forming apparatus which saves power by lowering the temperature of the fixing unit in the standby mode, the fixing unit is preheated when the temperature becomes lower than a preset temperature, even in the power saving mode. Therefore, there is a disadvantage that the energy is wasted when the standby time is long.

The technique proposed in Japanese Patent Application Laid-Open No. 9-185299 saves power by effectively utilizing, for example, a recovery time until the fixing device reaches a fixing temperature, and shortens the recovery time itself. It was not something.

Therefore, it is desirable to stop the power supply to the fixing device during standby to save power, and to supply the necessary and sufficient energy to the fixing device at startup to quickly start up. The amount is naturally limited.

For example, when power is supplied from a normal power line (outlet) in an office or home in Japan, there is a limit of 1500 W per line. For this reason, when 1500 W or more power is required at the time of startup, a special power line is required, such as preparing a dedicated outlet, and the versatility and installation of the device are significantly deteriorated.

Therefore, the present invention has been made in view of the above points,
It is possible to shorten the transition period (start-up time) from the first state (standby state) to the second state (state in which image formation can be started) regardless of the limitation of the power capacity of the power supply line, Another object of the present invention is to provide an image forming apparatus capable of saving energy.

[0015]

An image forming apparatus according to the present invention is characterized by the following constitution in order to solve the above-mentioned problems.

[1] An image forming apparatus which consumes a large amount of power during the transition from the first state to the second state has a plurality of energy supply means for supplying power during the transition. apparatus.

[2] Image forming means for forming an image on a recording material, image heating means for heating the image on the recording material, and control means for the image forming means or the image heating means. In the image forming apparatus, the power consumption during the period when the image forming unit, the image heating unit or the control unit shifts from the first state to the second state is larger than the power consumption during the first state and the second state. An image forming apparatus comprising: a plurality of energy supply units that supply power to at least one of the image forming unit, the image heating unit, and the control unit during the transition period.

[3] The plurality of energy supply means includes a main energy supply means for supplying power during the transition period and the second state, and a sub-energy supply means for supplying power only during the transition period. An image forming apparatus according to [1] or [2].

[4] The image forming apparatus according to [1], [2] or [3], wherein the first state is a standby state and the second state is a normal operation.

[5] The auxiliary energy supply means includes an energy storage means, and supplies the power stored in the energy storage means together with the power supply of the main energy supply means during the transition period. The image forming apparatus according to any one of [1] to [4].

[6] The image forming apparatus according to [5], wherein the energy storage means includes means for supplying energy from the main energy supply means during a period other than the transition period.

[7] The energy storage means is configured using electrochemical means. [5]
Or, the image forming apparatus according to [6].

[8] The image forming apparatus according to [7], wherein the energy storage means using the electrochemical means is a chargeable / dischargeable secondary battery.

[0024]

[9] The image forming apparatus according to [5], wherein the energy storage unit is a capacitor.

[10] The image forming apparatus according to [5], wherein the energy storage means includes a replaceable energy source.

[11] The image forming apparatus according to [5], wherein the energy storage means is a fuel cell.

[12] The image forming apparatus according to [2], wherein when the main energy supply unit is out of power, electric power is supplied from the sub energy supply unit instead of the main energy supply unit.

<Operation> With the above configuration, a start-up time (transition period) from the standby state (first state) to the state in which image formation can be started (second state).
In addition, since the required power can be supplied from the energy storage means in addition to the power from the power line such as an outlet, the startup time can be shortened regardless of the power capacity of the power line, and the temperature in the standby state can be reduced. It is possible to save energy by eliminating the need for key adjustment.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment 1. First Embodiment Overall Configuration of Image Forming Apparatus FIG. 7 is a schematic configuration diagram of the image forming apparatus of the present invention. The image forming apparatus of this embodiment is a laser beam printer using an electrophotographic process.

An image reading means 40 illuminates an original O placed on an original table with a light source 40a, and guides the reflected light from the original O to a CCD 40c by an optical system 40b, thereby causing the CCD 40c to emit the reflected light.
At 40c, the image information is read as an electric signal (image signal).

Reference numeral 41 denotes an electrophotographic photosensitive member (hereinafter, referred to as a photosensitive drum), which is driven to rotate at a predetermined peripheral speed (process speed) in a clockwise direction indicated by an arrow, and is uniformly rotated by a primary charger 42 during the rotation process. Is charged.

Reference numeral 43 denotes a laser beam scanner which outputs a laser beam L modulated in accordance with an image signal from the image reading means 40 and scans and exposes the uniformly charged surface of the rotating photosensitive drum 41. An electrostatic latent image corresponding to the image information is formed.

Reference numeral 44 denotes a developing unit which reversely develops the latent image with a powder toner (toner adheres to a laser-exposed light potential portion on the surface of the photosensitive drum) and visualizes the latent image as a toner image T.

On the other hand, the recording material P supplied from the paper supply cassette C is transferred to the pressure contact nip (transfer portion) m between the transfer roller 45 as a transfer member to which a transfer bias is applied and the photosensitive drum 41. The toner image T is fed at an appropriate timing synchronized with the rotation, and the toner image T on the photosensitive drum 41 side is transferred onto the recording material P by the transfer bias.

Then, each of these elements 41, 42, 4
The recording material P on which the unfixed toner image T has been formed by the image forming means constituted by 3, 44, 45 and the like is separated from the surface of the rotating photosensitive drum 41, and the fixing device (image heating means) described in the above embodiment. The toner image T is introduced into the R, undergoes a fixing process, and is discharged out of the apparatus as an image formed product (print).

If the image formation is not performed for a predetermined time after the image formation is discharged, the fixing unit R, the image forming means, these control means, and the like are controlled until the next image formation is instructed. The power supply is stopped or reduced to a standby state (power saving mode).

2. Schematic Configuration of Energy Supply System FIG. 1 is a schematic configuration diagram showing an energy supply system of the present embodiment.

In FIG. 1, reference numerals 1 and 3 denote energy supply means for supplying energy to an image forming means, an image heating means and the like. The main energy supply means 3 supplies energy during normal operation, and the main energy supply means 3 supplies energy during startup. Secondary energy supply means 1 for supplying energy together with supply means
It consists of

The auxiliary energy supply means 1 comprises an energy storage means 12 for electrochemically storing power by means.
And an adding means 2a for adding the output from the storage means 12 to the output of the main energy supply means 3, and a replenishing means 2b for supplying energy from the main energy supply means 3 to the storage means 12.

Reference numeral 4 denotes a line power supply supplied from a power company.

Reference numeral 5 denotes a block representing a fixing unit driving circuit (control circuit) and a fixing unit. Reference numeral 6 denotes a control circuit for controlling each unit constituting the image forming apparatus, and also includes an image processing unit. Reference numeral 7 denotes a drive circuit and a drive unit other than the above 5 and 6, which are the image forming means, a sorter unit, a sheet feeder unit, a panel display unit, and the like.

FIG. 2 shows the auxiliary energy supply means 1 at the time of startup.
FIG. 4 is an explanatory diagram of a circuit that supplies energy by combining the main energy supply means 3 with a power supply;

In the figure, reference numeral 20 denotes a block constituting one element of the main energy supply means 3, which includes a bridge rectifier diode 9, a choke coil 10, and a capacitor 11
Etc.

Reference numeral 17 denotes a block constituting one element of the sub-energy supply means 1. The secondary battery 12 is an energy storage means, a backflow preventing diode 13 for the secondary battery 12, and charging of the secondary battery 12. It comprises a current limiting resistor 14, a charge control switch 15 and a discharge control switch 16, and a SW operation control circuit 19 for controlling the switch operation of the switches 15, 16.

Reference numeral 18 denotes this entire block.

FIG. 3 is a diagram showing the voltage in the block for explaining the operation of the entire block 18. Referring to FIG.

The operation of each section in the above configuration will be described.

In FIG. 2, the AC power supplied from the line power supply 4 is first subjected to double-wave rectification by the bridge rectifier diode 9.

At this time, the voltage waveform between points A and B is
Draw an envelope as indicated by V1 in FIG. (In the figure, waveforms at certain times t1 to t2 are shown.) For example, when the fixing device R is off, the charge control switch 15
When is closed, energy is stored in the secondary battery 12 as the energy storage means. As this secondary battery, Ni-
A Cd battery, a Ni-hydrogen battery, a Li-ion battery, or the like is used.

It is the role of the current limiting resistor 14 to define the charging current at this time and determine the charging time. When the charging of the secondary battery 12 is completed, the voltage between the points C and B becomes V2 in FIG.
Is charged to the voltage indicated by and held.

At this time, the voltage V2 of the secondary battery 12 can be charged up to near the maximum voltage of the line power supply 4.

This state corresponds to the energy storage means 2
This is a state in which energy is stored in the secondary battery 12.

3. Description of Power Supply at Startup and FCOT Next, the image forming apparatus 8 of the present embodiment changes from a standby state or a power-off state (first state) to a normal operation, that is, a state in which an image is formed (second state). The control from start-up to the output of the first image (a period corresponding to FCOT in a copying machine and a period corresponding to FirstPrintTime in a printer) will be described.

First, when the power supply is turned off and the start of image formation is instructed in a state where the fixing device R is completely cooled, FIG.
The middle charge control switch 15 is turned off, and the discharge control switch 16 is turned on.

Then, at point D, the energy stored in the secondary battery 12 is supplied to the block 5 such as the fixing device R via the backflow preventing diode 13 to the secondary battery 12. The backflow prevention diode 13 of the secondary battery 12 prevents the secondary battery 12 from being rapidly charged at the time of control abnormality,
Work to protect the next battery.

When the temperature of the fixing unit R reaches a predetermined temperature, the discharge control switch 16 is turned off to turn on the auxiliary energy supply unit 1.
Is stopped, and power is supplied only to the main energy supply unit 3 to each of the elements 5, 6, and 7 to form an image. After completion of the image formation, the charge control switch 15 is closed and the secondary battery 1 is closed.
2 starts charging.

At this time, strictly speaking, as shown by the dotted line in the figure, unless a diode is inserted in the normal energy supply line, the maximum value of the power supply line corresponds to the forward voltage of the diode,
There is a section where the backflow prevention diode 13 is turned off, which may exceed 15 A at the peak. However, since this diode always flows current from the power supply line, it causes power loss and is not preferable from the viewpoint of energy saving.

Further, in a normal power supply line, a load having a large rush current exceeding 15 A, such as a light bulb, can be passed for a short time.

In the present embodiment, the peak current is smaller than the rush current of a light bulb or the like, and the peak value can be controlled, so that the configuration as in this example can be adopted.

FIG. 4 is a diagram schematically showing the power supplied to the image forming apparatus according to the embodiment of the present invention and the conventional example.

In the figure, A is a temperature pattern and a power supply pattern according to the present invention, and B is a conventional temperature pattern and a power supply pattern.

Speaking in Japan, a normal outlet is subject to a power limit of 1500 W per circuit.

If a dedicated outlet is prepared like an air conditioner, this limit is allowed up to 2000 W. However, the outlet becomes a dedicated outlet and the installability of the image forming apparatus is significantly deteriorated. Actually, the power factor should also be considered, but is omitted here for the sake of simplicity.

As shown in FIG. 7A, in the conventional example B,
The time required for the fixing device R to rise from a room temperature to a temperature at which fixing can be performed was b seconds.

At this time, since the conventional example B has the configuration shown in FIG.
It could only be applied to a value obtained by subtracting the electric power used in other than the fixing device from 0 W.

However, by using the present invention, the secondary batteries 12 to 150 serving as energy storage means can be used at the time of startup.
Since energy exceeding 0 W can be applied, the rise time of the fixing device R can be reduced to a second.

As can be seen from FIG. 4C, after fixing a series of images, the energy used at the time of startup is
If a sequence is stored in the secondary battery 12, the FCOT will not be reduced for the next use.

The energy required for starting corresponds to the area in the figure, but in principle, the area is not different from the conventional one, so that even if the FCOT is improved, no particular energy is required.

As described above, in the present embodiment, since it is possible to start up from the room temperature state in a relatively short time a, the power supply to the fixing device R can be turned off until the next image formation starts, and the standby temperature adjustment can be performed. Therefore, there is no need to consume unnecessary power.

On the other hand, in the case of the conventional example B, when starting up in a second similarly, it is necessary to control the temperature at a predetermined temperature at the time of standby as shown in FIG. The power indicated by d is required.

In a series of these controls, the SW operation control circuit 19 controls the on / off control of the switches 15 and 16 according to the exchange of signals from the image forming apparatus control circuit 6 (system control). By controlling the charging and discharging of the secondary battery 12 as described above.

The effect of this embodiment is that the limitation of 1500 W of power at the time of starting the fixing device can be practically eliminated, so that the FCOT can be accelerated. Therefore, the standby power of the fixing device R can be substantially reduced to zero.

Further, since the energy storage means is a secondary battery, a large power capacity can be obtained, and if necessary, power can be supplied to the required means instead of the main energy supply means 3, so that an unexpected power outage occurs. The advantage is that the image forming apparatus can be used even at the time. When applied to a facsimile or the like, a power outage occurs at the time of disaster, but when a telephone line is available, image transmission is possible, which is effective as a crisis avoidance means.

In the above embodiment, for example, the configuration of the characteristic energy supply means when the electromagnetic induction heating method is used as the fixing device is shown. However, it is possible to use the resistance heating method similarly. It can be used even in the case of a halogen lamp heating method.

<Second Embodiment> FIG. 5 shows a second embodiment of the present invention. The second embodiment is characterized in that a large-capacity capacitor 22 is used as energy storage means. In the figure, the configuration other than the large-capacity capacitor 22 is the same as that of FIG. Therefore, the basic operation is the same as in the first embodiment.

The capacitance value is determined by how much energy is supplied at the time of start-up.
(Millifarad) or more is required. Such a large-capacity capacitor can be configured using, for example, a plurality of electric double-layer capacitors in combination.

When the energy storage means is constituted by a large-capacity capacitor, the cost is lower than that of a secondary battery.

Unlike a secondary battery, there is almost no limitation on the number of charge / discharge cycles, so that there is an advantage that the product life is long and maintenance-free.

<Third Embodiment> FIG. 6 shows a third embodiment of the present invention. This third embodiment is characterized in that a fuel cell 32 is used as energy storage means.

The fuel cell 32 utilizes the transfer of electrons in a chemical reaction for producing water from hydrogen gas and oxygen gas, and uses the transfer of electrons as electric energy. In this case, the fuel cell is provided with a hydrogen storage means (such as a cylinder and a hydrogen absorber), and reacts using oxygen in the air to extract energy. After the reaction, water is generated.

Unlike the first and second embodiments, charging is not required, and when the reactant gas is consumed, the reactant gas can be replenished by replacing the cylinder or the like. Energy means.

The generated voltage is DC. In some cases, voltage conversion (DC-DC conversion or DC-AC conversion) is used depending on the type of the fixing device.

Since the operation of releasing the energy as the energy storage means is the same as that of the other embodiments, the description is omitted.

By constituting the energy storage means with a fuel cell, the power generated by the reaction of generating water from hydrogen and oxygen can be utilized without being limited by the power of 1500 W in the power supply line at the time of startup. It is possible to further advance.

In the above embodiment, the electric power from the auxiliary energy supply means is supplied only to the fixing device R at the time of start-up (transition period). However, the present invention is not limited to this. May be supplied with power. The transition period is not limited to the start-up period, but may be a period during which power consumption increases, such as in a thick paper passing mode.

[0086]

As described above, according to the present invention,
It is possible to shorten the transition period (start-up time) from the first state (standby state) to the second state (state in which image formation can be started) regardless of the limitation of the power capacity of the power supply line, Further, an image forming apparatus capable of saving energy can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an energy supply unit of an image forming apparatus according to a first embodiment.

FIG. 2 is a circuit diagram of an energy supply system according to the first embodiment.

FIG. 3 is a diagram showing voltage in a block for explaining the operation of block 18;

FIG. 4 is a diagram schematically illustrating power supply of an image forming apparatus according to an embodiment of the present invention and a conventional example.

FIG. 5 is a circuit diagram showing a second embodiment of the present invention.

FIG. 6 is a circuit diagram showing a third embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of an image forming apparatus.

FIG. 8 is a block diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Secondary energy supply means 2a Addition means 2b Replenishment means 3 Main energy supply means 4 Line power supply 8 Image forming apparatus 9 Bridge rectifier diode 10 Choke coil 11 Capacitor 12 Energy storage means (secondary battery) 13 Backflow prevention diode 14 Current limiting resistance 15 Charge control switch 16 Discharge control switch 19 SW operation control circuit 22 Large capacity capacitor 32 Fuel cell R Fixing device

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Atsuyoshi Abe 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H027 DA31 DE07 EA16 ED25 EE02 EF04 EF16 ZA01 ZA07 5G065 AA01 DA04 DA06 EA02 EA06 FA05 JA02 KA02 LA07 MA10 NA01

Claims (12)

[Claims] 1. An image forming apparatus in which power consumption increases during a transition from a first state to a second state, comprising: a plurality of energy supply means for supplying power during the transition. . 2. An image forming means for forming an image on a recording material, an image heating means for heating the image on the recording material, and a control means for the image forming means or the image heating means, In the image forming apparatus, the power consumption during a period when the image forming unit, the image heating unit, or the control unit shifts from the first state to the second state is larger than the power consumption during the first state and the second state. An image forming apparatus comprising: a plurality of energy supply units that supply power to at least one of the image forming unit, the image heating unit, and the control unit during a transition period. 3. The energy supply means includes a main energy supply means for supplying power during the transition period and the second state, and a sub energy supply means for supplying power only during the transition period. The image forming apparatus according to claim 1. 4. The system according to claim 1, wherein the first state is a standby state, and the second state is a normal operation.
Or the image forming apparatus according to 3. 5. The power supply device according to claim 1, wherein the auxiliary energy supply unit includes an energy storage unit, and supplies the power stored by the energy storage unit together with the power supply of the main energy supply unit during the transition period. Items 1 to 4
The image forming apparatus according to claim 1. 6. The image forming apparatus according to claim 5, wherein the energy storage unit includes a unit that supplies energy from a main energy supply unit during a period other than the transition period. 7. The image forming apparatus according to claim 5, wherein the energy storage unit has a configuration using an electrochemical unit. 8. The image forming apparatus according to claim 7, wherein the energy storage means using the electrochemical means is a chargeable / dischargeable secondary battery. 9. The image forming apparatus according to claim 5, wherein said energy storage means is a capacitor. 10. The image forming apparatus according to claim 5, wherein said energy storage means includes an exchangeable energy source. 11. The image forming apparatus according to claim 5, wherein the energy storage unit is a fuel cell. 12. The image forming apparatus according to claim 2, wherein when the main energy supply unit fails, power is supplied from a sub energy supply unit instead of the main energy supply unit.