JPH10304563A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image-forming apparatus which does not stop operating, even when a power supplying part which supplies power to a control system fails. SOLUTION: In an image-forming apparatus having a control unit 9 for controlling its operation, a power-supplying part 1 supplies power to the control unit 9, and a power supplying part 3 supplies power to members other than the control unit 9 of the image-forming apparatus When the power supply to the control unit 9 by the power-supplying part 1 stops, a switch 15 having a switching part 7 changes its connection so that power is supplied to the control unit 9 by the powersupplying part 3.

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, and more particularly, to a two-converter type image forming apparatus having two power supply units.

[0002]

2. Description of the Related Art At present, various functions are required for an image forming apparatus. Among them, there is a strong demand for power saving (energy saving) of the power consumed by the image forming apparatus.

In order to achieve the above-mentioned power saving, in the internal structure of the image forming apparatus, a part for supplying power is used as a part for supplying power.
One part is divided into a part of a control system that controls the entire image forming apparatus, one part is divided into parts other than the control system in the image forming apparatus, and the other part supplies power to a part of the control system that controls the entire image forming apparatus. 2. Description of the Related Art There has been proposed an image forming apparatus including two power supply units, one power supply unit and a second power supply unit that supplies power to a portion other than a control system in the image forming apparatus.

[0004] The power supply unit for supplying power includes a first power supply unit for supplying minimum power to a control system and members other than the control system provided in the image forming apparatus, for example,
An energy-saving mode, which is a mode for executing power saving of the power consumed by the image forming apparatus, is set as a two-converter system including a driving system, a high-voltage power supply, and a second power supply unit for supplying power to sensors and the like. In this case, the image forming apparatus is configured to stop the converter of the second power supply unit and supply power only to the control system by the first power supply unit, thereby saving power of the apparatus.

As described above, the power supply unit which plays an important role in the image forming apparatus and stops the operation of the image forming apparatus stops the operation of the entire image forming apparatus. By dividing the power supply unit into two, a power supply unit that supplies power to the power supply unit, power can be used efficiently, and as a result, it is possible to reduce the power consumption of the image forming apparatus.

In general, a DC power supply is used as a first power supply for supplying power to the control system.

[0007]

However, in the prior art as described above, the power supply unit for supplying power is divided into two parts, and the power supply is used efficiently to reduce the power consumption of the image forming apparatus. Although the power supply unit that supplies power to the control system and the power supply unit that supplies power to parts other than the control system are, for example, the power supply unit that supplies power to the control system fails, and the parts other than the control system fail. In some cases, the power supply units that supply power to the power supply units may fail separately, for example, as if they were normal.

In this case, a power supply unit for supplying power
If the power supply unit that supplies power to the control system fails, the power supply unit that supplies power to parts other than the control system fails. However, the operation of the entire image forming apparatus is stopped even if it is not performed, and there is a problem that the use efficiency thereof is remarkably deteriorated.

The present invention has been made in view of the above circumstances,
In a two-converter image forming apparatus having two power supply units, an image capable of preventing the operation of the image forming apparatus from being stopped even when a power supply unit that supplies power to a control system fails. It is an object to provide a forming device.

[0010]

According to the first aspect of the present invention,
In an image forming apparatus having a control system for controlling the operation of the image forming apparatus, a first power supply for supplying power to the control system and a second power supply for supplying power to members other than the control system of the image forming apparatus A power supply; and switching means for switching the connection so that the power supply to the control system is supplied by the second power supply when the supply of power to the control system by the first power supply is stopped. And

Therefore, according to the present invention, a power supply for supplying power to a control system provided in the image forming apparatus and a power supply for supplying power to members other than the control system provided in the image forming apparatus are provided.
When the power supply to the control system from the power supply for supplying power to the control system is stopped, the connection for supplying power is switched, and the control system included in the image forming apparatus is provided. Because it is possible to supply power to the control system from the power supply that supplies power to other members, even if the supply of power to the control system from the power supply that supplies power to the control system stops, It is possible to prevent the operation of the image forming apparatus from stopping.

According to a second aspect of the present invention, in the first aspect of the present invention, the first power supply is a DC power supply.

Therefore, according to the present invention, the operation of the first aspect can be obtained, and a DC power supply (DC power supply) can be used as a power supply for supplying power to the control system.

According to a third aspect of the present invention, in the first or second aspect of the present invention, it is detected whether or not the supply of power to the control system by the first power supply is stopped, and the detection result is represented. It has a detecting means for outputting a detection signal to the control system.

Therefore, according to the present invention, the operation of the invention described in claim 1 or 2 can be obtained, and the detecting means detects whether or not the supply of power to the control system has been stopped. Is output to the control system, the supply of power to the control system from the power supply that supplies power to the control system stops, and the power supply that supplies power to components other than the control system included in the image forming apparatus Even when power is being supplied to the control system, it can be confirmed that the supply of power from the power supply that supplies power to the control system has stopped.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the switching means includes:
A switch is provided for switching the connection based on a power supply output from the first power supply.

Therefore, according to the present invention, the operation of the invention according to any one of claims 1 to 3 is obtained, and the connection is switched based on the power supply output from the first power supply. Even if the power supplied from the power supply stops, the power can be reliably supplied from the second power supply to the control system.

[0018]

Next, an embodiment of an image forming apparatus according to the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of a circuit diagram of a power supply unit included in the image forming apparatus according to the present invention.

As shown in FIG. 1, the power supply unit includes a power supply unit 1 for supplying power to the control unit 9 and a power supply unit 3 for supplying power to parts other than the control unit 9 of the image forming apparatus.
And a transistor 5 having a gate electrode connected to the power supply 1.
A switching unit 7 having a switch 15 for switching the connection between the power supply unit 1 and the power supply unit 3; a control unit 9 having a CPU 11 therein and controlling the operation of the entire image forming apparatus;
A wiring 13 for transmitting to the CPU 11 a signal 1 indicating whether or not the supply of power from the power supply unit 1 to the control unit 9 is stopped; and a connection between the power supply unit 1 and the power supply unit 3. , A power supply terminal 17 for supplying power to the control unit 9, and a power supply line 19 connected to the power supply terminal 17 for supplying power to the control unit 9.

In FIG. 1, R1, R2, R3 and R4 are resistors, and C1 is a capacitor.

Next, the operation of power supply in the power supply circuit shown in FIG. 1 will be described.

First, an AC power input from an AC power input (not shown) passes through a noise filter, is rectified and smoothed by a diode bridge and a capacitor (both not shown), and then input to the power supply unit 1 and the power supply unit 3. I do.

The power supplied from the power supply unit 1 is input to the control unit 9 as shown in FIG. This power supply is a power supply supplied to the control unit 9 and is a power supply used only for the control unit 9, so that the capacity of the power supply is small.

Therefore, the voltage of the power supplied from the power supply unit 1 is generally preferably about 5V. In the present embodiment, hereinafter, the voltage of the power supplied from the power supply unit 1 is set to 5V. However, if necessary, the voltage of the power supply unit 1 may be, for example, 3V or 12V.

On the other hand, the power supply unit 3 is a power supply unit for supplying power to members other than the control unit 9 provided in the image forming apparatus shown in FIG. Examples of members provided in the image forming apparatus other than the control unit 9 include a drive system, a high-voltage power supply, and sensors.

As described above, since the power supply unit 3 supplies power to various members provided in the image forming apparatus, the output power supply usually outputs a power supply voltage according to each usage mode. It is a possible multiple output power supply. Therefore, a voltage of 24 V, ± 12 V, 5 V, or the like can be output as a voltage of the power supply, and a voltage required by the control unit 9 can also be output.

Since the power supply capacity (current) required by the control unit 9 is small, the current supplied when the power supply unit 3 is a power supply of 5V includes the current supplied by the power supply unit 1. Even if the power supply unit 3 is not provided, there is little difference between the configuration and the cost. Therefore, in the present invention, the current output when the power supply unit 3 is 5 V includes the current output from the power supply unit 1.

Here, it is assumed that the energy saving mode is set for the image forming apparatus. This setting may be set by an operation panel (not shown) provided in the image forming apparatus, or may be set automatically.

This energy saving mode is a mode for suppressing the power consumed by the image forming apparatus. Then, for example, when the energy saving mode is selected by the above-described setting method, only the power supply unit 1 shown in FIG.
Is supplied only to the power supply.

In the state of the energy saving mode, as described above, power is supplied only from the power supply unit 1 to the control unit 9 and power is not supplied from the power supply unit 3, so that the power of the image forming apparatus is reduced. Consumption can be reduced.

Next, a case where the supply of power to the control unit 9 is stopped, that is, a case where some trouble such as a disconnection occurs in the power supply unit 1 or its power supply path will be described.

If both the power supply unit 1 and the power supply unit 3 are in a normal state, power of 5 V is supplied from the power supply unit 1 so that the switch 15 of the switching unit 7 shown in FIG.
Is connected to the A contact side, and the power terminal 1 of the control unit 9
7 is supplied with power from the power supply unit 1 via a power supply line 19.

Here, when the power supply from the power supply unit 1 is stopped, the switch 1 of the switching unit 7 shown in FIG.
Reference numeral 5 is connected to the B contact side, and the same power as the power supplied by the power supply 1 is supplied to the power supply terminal 17 of the control unit 9 from the power supply 3 via the power supply line 19.

Therefore, with the circuit configuration shown in FIG. 1, even when the power supply from the power supply unit 1 is stopped, it is possible to operate the image forming apparatus without stopping the image forming apparatus. However, in this case, the control unit 9 is operated by the power supplied from the power supply unit 3.

However, since the power consumed by the power supplied from the power supply unit 3 is large, it is not possible to set an energy saving mode for suppressing the power consumption of the image forming apparatus.
Therefore, when the supply of power from the power supply unit 1 is stopped, it is necessary to output a signal to the CPU 11 to display that the energy saving mode cannot be set.

To indicate that the energy saving mode cannot be set, the switch 15 of the switching unit 7 shown in FIG. 1 is connected to the B contact. Therefore, the transistor 5 is turned on because a voltage from the power supply unit 1 is applied to the gate electrode. Therefore, a signal 1 is generated by the resistor and the transistor 5, and the generated signal 1 is transmitted through the wiring 13 to the control unit 9.
Is output to the CPU 11 provided therein.

Therefore, in the circuit shown in FIG.
If the power supply from the power supply unit 1 to the control unit 9 is normal,
The level of the signal 1 is in a “low” state L, and the level of the signal 1 is in a “high” state H when the supply of power from the power supply unit 1 to the control unit 9 is stopped.

Therefore, according to this embodiment, the control unit 9
It is possible to prevent the operation of the image forming apparatus from stopping even when the power supply from the power supply unit 1 that supplies power to the power supply unit stops.

The power supply unit 1 for supplying power to the control unit 9
Even when the power supply from the CPU 11 is stopped, the stopped state can be confirmed by the CPU 11 inputting the signal 1 generated by the transistor 5.

[0040]

As is apparent from the above description, according to the present invention, a power supply for supplying power to the control system of the image forming apparatus and a power supply for supplying power to members other than the control system of the image forming apparatus are provided. By providing the two power supplies, the power saving of the image forming apparatus can be realized, and even if a failure occurs in the power supply for supplying power to the control system of the image forming apparatus, the switching unit can be used. Since switching is performed so that power is supplied to the control system by the second power supply, it is possible to provide an image forming apparatus capable of preventing the operation of the image forming apparatus from being stopped.

Since the power supply for supplying power to the control system of the image forming apparatus is a DC power supply, an image forming apparatus capable of preventing the operation of an image forming apparatus having various control systems from being stopped is provided. Can be provided.

The detecting means detects whether or not the supply of power to the control system by the first power supply is stopped, and outputs a detection signal representing the detection result to the control system. Even when power supply to the control system of the apparatus is stopped and power is supplied to the control system from a power supply that supplies power to members other than the control system of the image forming apparatus, control by the first power supply is also possible. It can be easily confirmed that the supply of power to the system has stopped.

Further, the switching of the connection of the power supply to the control system by the switching means is switched based on the power supply output from the first power supply, so that the power supply from the first power supply is stopped. Also, it is possible to provide an image forming apparatus capable of reliably supplying power to the control system from the second power supply.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of an embodiment of a power supply circuit included in an image forming apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power supply part 3 Power supply part 5 Transistor 7 Switching part 9 Control part 11 CPU 13 Wiring 15 Switch 17 Power supply terminal R1, R2, R3, R4 Resistance C1 Capacitor

Claims (4)

[Claims] An image forming apparatus having a control system for controlling the operation of the image forming apparatus, wherein a first power supply for supplying power to the control system and a power supply for members other than the control system of the image forming apparatus are provided. A second power supply to be supplied, and switching means for switching a connection so as to supply power to the control system by the second power supply when the supply of power to the control system by the first power supply is stopped. An image forming apparatus comprising: 2. The image forming apparatus according to claim 1, wherein said first power supply is a DC power supply. And detecting means for detecting whether or not supply of power to the control system by the first power supply is stopped, and outputting a detection signal indicating the detection result to the control system. The image forming apparatus according to claim 1. 4. The image forming apparatus according to claim 1, wherein the switching unit includes a switch that switches a connection based on a power supply output from the first power supply.