JP2016085310A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To curb occurrence of a situation in which a function of an option device cannot be exerted, and attain power saving.SOLUTION: An image formation device includes: an electric current detection unit 12 that detects electric current flowing from a main body device 1 to an option device 2 accompanying supply of electric power by a power source device 11; and a comparator 13 that compares a value of the electric current detected by the electric current detection unit 12 with an electric current upper limit value Ref, and when the value of the electric current is larger than the electric current upper limit value Ref, transmits an electric current upper limit signal indicating the effect to the option device 2. When a drive state of the option device 2 is such that a sheet 32 in a tray 31 is on the rise to a sheet feeder position by a lift motor 21, when an option control unit 24 receives the electric current upper limit signal from the comparator 13, the lift motor 21 is configured to be halted.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image forming apparatus such as, for example, a printer, a copying machine, and a facsimile. In particular, when at least one or more optional devices are connected, the total value of currents flowing through the entire optional devices does not exceed an upper limit value. Thus, the present invention relates to an image forming apparatus capable of reducing the power consumption.

Image forming apparatuses have a tendency to increase power consumption with the increase in color and speed of images, or support for multiple paper handling options (for example, duplex option, paper feed option, paper discharge option, etc.) Yes.
In such a situation where power consumption tends to increase, it is becoming difficult to satisfy the ratings of outlets and breakers, and to satisfy power saving standards such as Energy Star.
Further, since it is necessary to mount a large power supply unit in the image forming apparatus, there are problems such as an increase in the size of the apparatus and an increase in heat generation from the power supply unit.

In order to solve the above problems, the power supply unit of the image forming apparatus is divided into a plurality of units, and AC plugs for the plurality of power supply units are separately installed, thereby reducing the burden on one outlet and the heat generation from the power supply unit. A method of dispersing is known.
In addition, a method is known in which energy control is achieved by remotely controlling a plurality of power supply units so that only the master power supply unit is driven without driving the slave power supply unit during sleep of the image forming apparatus. It has been.
However, when the above method is used, there is a problem that the cost of the power supply unit is remarkably increased.

Therefore, as a technique for solving the above problem without using the above technique, a technique for reducing the maximum current consumption during the operation of the image forming apparatus has been proposed.
For example, Patent Document 1 below discloses an image forming apparatus in which power supply to a plurality of drive units is switched according to a change in voltage supplied from a power supply apparatus.
Further, Patent Document 2 below discloses an image forming apparatus in which some driving units are stopped during a period including a moment when the current consumption of the processing unit becomes maximum.

In Patent Document 3 below, when the total power consumption of a plurality of external devices (for example, color printers) connected to the image forming apparatus is larger than the maximum power supply amount, it is set by a user operation. An image forming apparatus is disclosed that supplies power according to a functional unit operation mode.
Further, in Patent Document 4 below, when there is a possibility that the total current consumption of all the load circuit units may exceed the upper limit value, the operation states of some load circuit units are waited according to a predetermined priority order. A multifunction device is disclosed that is adapted to switch to a state.

JP 2006-201386 A JP 2005-345663 A JP 2012-022234 A JP 2009-182460 A

  Since the conventional image forming apparatus is configured as described above, the maximum current consumption during the operation of the image forming apparatus can be reduced. However, Patent Documents 1, 2, and 4 are not related to the optional device. Patent Document 3 does not limit the operation of some of the drive units in consideration of the function of the optional device. For this reason, among the multiple drive units mounted on the optional device, the drive unit that does not affect the performance of the optional device function is not necessarily the drive unit subject to the operation restriction, and the optional device function is exhibited. There was a problem that situations where it was impossible to occur frequently occurred. Further, when the operation of the driving unit is restricted by a user operation, the operation of the image forming apparatus does not automatically continue, and the operation becomes complicated.

  The present invention has been made to solve the above-described problems, and can suppress the occurrence of a situation in which the function of the optional device cannot be exhibited, thereby reducing power consumption while avoiding complicated operations by the user. It is an object of the present invention to obtain an image forming apparatus that can be used.

  An image forming apparatus according to the present invention includes an optional device in which a plurality of driving units are mounted, a main device that supplies driving power to the optional device, and flows from the main device to the optional device as power is supplied. If the comparison result of the comparison circuit indicates that the current value is larger than the upper limit value, a comparison circuit for detecting the current value and comparing the current value with a preset upper limit value is provided. The option control unit continues the operation of at least one drive unit among the plurality of drive units so as to exhibit the function of the option device, and restricts the operation of the other drive units in the plurality of drive units. It is a thing.

  In the image forming apparatus according to the present invention, a plurality of optional devices are mounted, and the comparison circuit detects the sum of currents flowing from the main body device to the plurality of optional devices as power is supplied, and The total control value is compared with the preset upper limit value, and if the comparison result of the comparison circuit indicates that the total current value is larger than the upper limit value, the option control unit switches to the drive state of a plurality of option devices. Accordingly, the operation of some drive units mounted on at least one option device among a plurality of option devices is limited, and the operation of the drive units mounted on the remaining option devices is maintained. It is.

  The image forming apparatus according to the present invention is such that the main unit stops supplying power to the drive unit of the optional device that does not affect the function of the optional device even when the main device is stopped.

  In the image forming apparatus according to the present invention, a plurality of option devices are connected in cascade to the main body device, and each option device receives a sheet in its own device or a sheet conveyed by the option device on the lower side. It has a function of transporting it to the option device or the main device on the upper stage side.

  In the image forming apparatus according to the present invention, the optional device as a drive unit includes a lift motor that raises the paper in the tray to the paper feed position, and a paper feed motor that feeds the paper raised to the paper feed position by the lift motor. And a transport motor that transports the paper fed by the paper feed motor, and when the drive state of the optional device is when the paper in the tray is being raised to the paper feed position by the lift motor, If the comparison result indicates that the current value is larger than the upper limit value, the option control unit stops the lift motor.

  In the image forming apparatus according to the present invention, after the lift motor is stopped, if the comparison result of the comparison circuit indicates that the current value is smaller than the upper limit value, the option control unit stops the lift motor. Is to start.

  In the image forming apparatus according to the present invention, a capacitor is connected between a power supply line for transmitting power to be supplied from the main body device to the optional device and the ground so that a current having a value larger than the upper limit value can flow temporarily. It is what you have done.

  In the image forming apparatus according to the present invention, the comparison circuit is mounted in the main unit, the option control unit is mounted in the option unit, and the comparison circuit in the main unit displays information indicating the comparison result in the option unit. This is sent to the option control unit.

  According to the present invention, it is possible to suppress the occurrence of a situation in which the function of the optional device cannot be exhibited, and to save power while avoiding complicated operations by the user.

1 is a configuration diagram illustrating an image forming apparatus according to Embodiment 1 of the present invention; It is a block diagram which shows the option apparatus 2 of the image forming apparatus by Embodiment 1 of this invention. 3 is a flowchart showing the processing contents of the image forming apparatus according to Embodiment 1 of the present invention. 7 is a timing chart showing an example of a case where the drive of the lift motor 21 is not restricted so that the value of the current flowing through the option device 2 does not exceed the current upper limit value Ref. 6 is a timing chart showing an example in which the drive of the lift motor 21 is limited so that the value of the current flowing through the option device 2 does not exceed the current upper limit value Ref. It is a block diagram which shows the image forming apparatus by Embodiment 2 of this invention. 3 is an explanatory diagram showing an example in which three optional devices 2-1, 2-2, 2-3 are connected in cascade to the main body device 1. FIG. 6 is a timing chart illustrating an example of a case where the drive of the lift motor 21 is not limited so that the total value of the currents flowing through the option devices 2-1 and 2-2 does not exceed the current upper limit value Ref. FIG. 6 is a timing chart showing an example when the drive of the lift motor 21 of the option device 2-2 is limited so that the total value of the currents flowing through the option devices 2-1 and 2-2 does not exceed the current upper limit value Ref. is there. It is a block diagram which shows the image forming apparatus by Embodiment 3 of this invention. It is a top view which shows the example whose option apparatus 2 connected to the main body apparatus 1 is a discharge | emission option.

Embodiment 1 FIG.
1 is a block diagram showing an image forming apparatus according to Embodiment 1 of the present invention.
In the first embodiment, an image forming apparatus in which one optional device 2 is connected to the main body device 1 will be described.
In FIG. 1, the main unit 1 corresponds to, for example, a main unit such as a printer, a copying machine, a facsimile, etc., and a command (in FIG. 1, “ This is a device that controls the operation of the option device 2 by transmitting to the option device 2.

The optional device 2 is mounted with drive units such as a lift motor 21, a paper feed motor 22, and a transport motor 23, and operates according to a command (CMD) transmitted from the main body device 1, for example, for paper feed and discharge. It is a device that performs a predetermined function such as paper.
The main device 1 and the option device 2 are connected by a bus, and an interface signal of the bus includes a command signal indicating a command (CMD) transmitted from the main device 1 to the option device 2 and the option device 2 is the device. It comprises a status signal for informing the main device 1 of a status indicating the status (indicated as “STS” in FIG. 1).

The power supply device 11 of the main body device 1 is a power supply that supplies driving power to the option device 2.
The current detection unit 12 of the main device 1 detects a current flowing from the main device 1 to the option device 2 as power is supplied from the power supply device 11, and outputs a current detection signal indicating the value of the current to the comparator 13. It is a current detector.
The comparator 13 of the main body device 1 compares the current value indicated by the current detection signal output from the current detection unit 12 with the current upper limit value Ref output from the main body control unit 14, and the current value indicated by the current detection signal is obtained. When the current upper limit value Ref is larger than the current upper limit value Ref, a current upper limit signal indicating that the current value is larger than the current upper limit value Ref is transmitted to the option device 2 as information indicating the comparison result.
Note that the current detection unit 12 and the comparator 13 constitute a comparison circuit.

  The main body control unit 14 of the main body device 1 is a control unit that controls the entire main body device 1. For example, in addition to outputting a preset current upper limit value Ref to the comparator 13, The reception processing of the status signal transmitted from the option device 2 is performed.

The lift motor 21 of the option device 2 is a drive unit that raises the paper in the tray to the paper feeding position.
The sheet feeding motor 22 of the option device 2 is a drive unit that feeds the sheet raised to the sheet feeding position by the lift motor 21.
The transport motor 23 of the option device 2 is a drive unit that transports the paper fed by the paper feed motor 22.
The option control unit 24 of the option device 2 is a control unit that restricts the operation of some of the drive units when receiving the current upper limit signal from the comparator 13 of the main body device 1.
That is, the option control unit 24 stops the lift motor 21 when the drive state of the option device 2 receives the current upper limit signal from the comparator 13 when the paper in the tray is being raised to the paper feed position by the lift motor 21. To control.
Further, after the lift motor 21 is stopped, the option control unit 24 performs control to start the stopped lift motor 21 when the current upper limit signal is not output from the comparator 13.

FIG. 2 is a block diagram showing an optional device 2 of the image forming apparatus according to Embodiment 1 of the present invention.
In FIG. 2, a tray 31 is a container for storing paper 32 and is inserted into a predetermined position of the option device 2.
A sensor unit 33 (denoted as “SW1” in FIG. 2) is a sensor that detects whether or not the tray 31 is inserted at a predetermined position of the option device 2.
The sensor unit 34 (denoted as “SW2” in FIG. 2) is a sensor that detects whether or not the paper 32 in the tray 31 has been raised to the paper feed position.

The two rollers 35 are rotating members for paper feeding that are rotated by the paper feeding motor 22.
The roller 36 is a rotation member for conveyance that is rotated by the conveyance motor 23.
In FIG. 2, the lift motor 21 is represented by “MT1”, the paper feed motor 22 is represented by “MT2”, and the transport motor 23 is represented by “MT3”.

Next, the operation will be described.
FIG. 3 is a flowchart showing the processing contents of the image forming apparatus according to Embodiment 1 of the present invention.
FIG. 4 is a timing chart showing an example when the drive of the lift motor 21 is not restricted so that the value of the current flowing through the option device 2 does not exceed the current upper limit value Ref.
FIG. 5 is a timing chart showing an example when the drive of the lift motor 21 is limited so that the value of the current flowing through the option device 2 does not exceed the current upper limit value Ref.

The power supply device 11 of the main body device 1 supplies driving power to the option device 2 and also supplies driving power to the main body control unit 14 and the like.
When the power is supplied from the power supply device 11, the main body control unit 14 outputs, for example, a current upper limit value Ref that is set in advance to the image forming apparatus or that is set by the operation of the apparatus administrator to the comparator 13. . Alternatively, the current upper limit value Ref transmitted from the outside via the Internet or LAN is output to the comparator 13.

Thereafter, the main body control unit 14 transmits a command (CMD) for exerting a desired function to the option device 2.
In the first embodiment, for the sake of convenience of explanation, an example will be described in which a command (CMD) for instructing the feeding of the paper 32 from the tray 31 and the conveyance of the paper 32 to the main body device 1 is transmitted to the option device 2.
When the option device 2 receives a power supply from the power supply device 11 of the main device 1 and receives a command (CMD) instructing the feeding and conveyance of the paper 32 from the main body control unit 14 of the main device 1, The paper feed motor 22 and the transport motor 23 are driven to realize the paper feed and transport of the paper 32.

The paper feeding process of the paper 32 by the paper feeding motor 22 is a flow until the leading edge of the paper 32 in the tray 31 reaches the position of the roller 36, and then the paper 32 is transported by the transport motor 23. Until the process is completed, the next sheet (lower sheet) of the sheet 32 cannot be fed, and the sheet feeding motor 22 stops during that period. For this reason, in the timing charts of FIGS. 4 and 5, the paper feed motor 22 is intermittently driven. In the example of FIGS. 4 and 5, since the paper feed motor 22 is driven three times, three sheets of paper 32 are fed.
Further, in order to feed the paper 32, the paper 32 in the tray 31 needs to be lifted to a position where the paper can be fed. The position where paper can be fed generally has a certain width. For example, the upper limit of the position where paper can be fed is in the vicinity of the upper opening position of the tray 31, and paper can be fed to a position several millimeters to several tens of millimeters below the upper opening position.
Hereinafter, the upper limit position of the paper feedable position is represented by _PUPP , and the lower limit position of the paper feedable position is represented by _PBOT .

When the power supply device 11 starts supplying power to the optional device 2, the current detection unit 12 of the main device 1 detects the current flowing from the main device 1 to the optional device 2 as the power is supplied, and the current Is output to the comparator 13.
When the comparator 13 receives the current detection signal I from the current detection unit 12, the comparator 13 compares the current value indicated by the current detection signal I with the current upper limit value Ref output from the main body control unit 14.
When the current value indicated by the current detection signal I is greater than the current upper limit value Ref, the comparator 13 transmits a current upper limit signal indicating that the current value is greater than the current upper limit value Ref to the option device 2.
For example, if the signal level of the output terminal of the comparator 13 is H level, this corresponds to transmitting the current upper limit signal to the option device 2, and if the signal level of the output terminal of the comparator 13 is L level, This corresponds to not transmitting the upper limit signal to the option device 2.

When the option control unit 24 receives power supply from the power supply device 11, the option control unit 24 obtains the sensing result of the sensor unit 33 and determines whether or not the tray 31 is inserted at a predetermined position of the option device 2 (see FIG. 3 step ST1).
When the option control unit 24 determines that the tray 31 is not inserted into a predetermined position of the option device 2, the option control unit 24 cannot lift the paper 32 in the tray 31. The motor 21 is stopped (step ST2). As this case, it is assumed that the tray 31 inserted in the option device 2 is pulled out while the lift motor 21 is driven. On the other hand, if the lift motor 21 is stopped, the lift motor 21 is kept stopped.
If the lift motor 21 is merely stopped, if the current value indicated by the current detection signal I exceeds the current upper limit value Ref, and the paper feed motor 22 and the transport motor 23 are also driven, the paper feed motor 22 or the transport The motor 23 is stopped.

When it is detected that the tray 31 is not inserted into the predetermined position of the option device 2, the option control unit 24 transmits a status signal indicating that the tray 31 is not inserted into the predetermined position to the main body control unit 14. If the function is provided, the status signal is transmitted to the main body control unit 14.
The main body control unit 14 of the main body device 1 transmits a command (CMD) instructing the feeding and conveyance of the paper 32 to the option device 2 in a situation where the status signal as described above is received from the option control unit 24. Do not. Thereby, useless command (CMD) transmission processing can be avoided.

When the option control unit 24 determines that the tray 31 is inserted at a predetermined position of the option device 2, the option control unit 24 obtains the sensing result of the sensor unit 34 and reaches the position where the paper 32 in the tray 31 can be fed. It is determined whether or not it is lifted (step ST3).
The option control unit 24 can feed the paper 32 in the tray 31 even if the lift motor 21 is stopped when the paper 32 in the tray 31 has already been lifted up to a feedable position. Then, the lift motor 21 is stopped (step ST2).
However, when the paper feed motor 22 continues feeding paper 32 while the lift motor 21 is stopped, the position of the paper 32 in the tray 31 gradually decreases, and the position of the paper 32 can be fed. If the position is lower than the position, the sheet 32 cannot be fed.
Therefore, when the sensor unit 34 detects that the position of the paper 32 is the lower limit position P _BOT of the _feedable position, if the option control unit 24 stops the lift motor 21, the lift motor 21 For example, the sensor unit 34 detects that the position of the paper 32 is the upper limit position P _UPP of the paper feedable position because the duration of paper feeding of the paper 32 in the stopped state becomes extremely short. When this happens, the option control unit 24 stops the lift motor 21. As a result, it is possible to lengthen the continuous feeding time of the paper 32 in a state where the lift motor 21 is stopped.

When the sheet 32 in the tray 31 is not lifted to a position where the sheet can be fed, the option control unit 24 determines the value of the current flowing through the option device 2 depending on whether or not the current upper limit signal is transmitted from the comparator 13. Is determined to exceed the current upper limit value Ref (step ST4).
When the value of the current flowing through the option device 2 does not exceed the current upper limit value Ref, the option control unit 24 maintains the drive of the lift motor 21 (step ST5). When the lift motor 21 is stopped, the lift motor 21 is restarted.

When the value of the current flowing through the option device 2 exceeds the current upper limit value Ref, the option control unit 24 suppresses the value of the current flowing through the option device 2 below the current upper limit value Ref to save power. Then, the lift motor 21 is stopped (step ST6). When the lift motor 21 is stopped, the lift motor 21 is kept stopped.
In the example of FIG. 4, when the paper feed motor 22 and the transport motor 23 are driven, when the lift motor 21 is driven, the value of the current flowing through the option device 2 exceeds the current upper limit value Ref. In the example, since the lift motor 21 is immediately stopped when the value of the current flowing through the option device 2 exceeds the current upper limit value Ref, the value of the current flowing through the option device 2 is suppressed to the current upper limit value Ref or less. Yes.
4 and 5 show an example in which the value of the current flowing through the option device 2 exceeds the current upper limit value Ref when the lift motor 21, the paper feed motor 22, and the transport motor 23 are simultaneously driven. This is merely an example, and when the power consumption in the option control unit 24 or other drive unit (not shown) in the option device 2 is small, the lift motor 21, paper feed motor 22, and transport motor 23 are driven simultaneously. However, the value of the current flowing through the option device 2 may not exceed the current upper limit value Ref.

When the lift control unit 21 is stopped, the option control unit 24 maintains the stop of the lift motor 21 while the paper feed motor 22 and the transport motor 23 are being driven (step ST7).
For example, when the paper feed motor 22 or the transport motor 23 stops with the completion of paper feed or transport of the paper 32 (step ST7), the option control unit 24 supplies power to the extent that the lift motor 21 can be driven. Since there is a possibility that the consumption amount has decreased, the process returns to step ST1 and the same process as described above is repeated.

  As is apparent from the above, according to the first embodiment, the current flowing from the main body device 1 to the option device 2 as the power is supplied from the power supply device 11 is detected, and the current detection indicating the value of the current is detected. The current detection unit 12 that outputs the signal I to the comparator 13, the current value indicated by the current detection signal I output from the current detection unit 12 and the current upper limit value Ref output from the main body control unit 14 are compared, and the current When the current value indicated by the detection signal I is greater than the current upper limit value Ref, a comparator 13 is provided for transmitting to the option device 2 a current upper limit signal indicating that the current value is greater than the current upper limit value Ref. When the drive state of the optional device 2 is that the paper 32 in the tray 31 is being raised to the paper feed position by the lift motor 21, the current upper limit is output from the comparator 13. Since the lift motor 21 is configured to stop when the signal is received, it is possible to save power while suppressing the occurrence of a situation in which the function of the option device 2 (the function of feeding and transporting the paper 32) cannot be performed. There is an effect that can be.

Embodiment 2. FIG.
In the first embodiment, an example in which one option device 2 is connected to the main device 1 is shown. However, in this second embodiment, a plurality of option devices 2 are connected to the main device 1. An example will be described.
6 is a block diagram showing an image forming apparatus according to Embodiment 2 of the present invention. In FIG. 6, the same reference numerals as those in FIG.
In the example of FIG. 6, three optional devices 2-1, 2-2, 2-3 are connected to the main device 1.

In the second embodiment, since the three optional devices 2-1, 2-2, 2-3 are connected to the main body device 1, the current detection unit 12 of the main body device 1 A total sum of currents flowing from the main unit 1 to the three optional devices 2-1, 2-2, 2-3 with the supply is detected, and a current detection signal I indicating the sum of the current values is sent to the comparator 13. Output.
When the option control unit 40 of the option devices 2-1, 2-2 and 2-3 receives the current upper limit signal from the comparator 13, the option control unit 40 switches to the drive state of the three option devices 2-1, 2-2 and 2-3. Accordingly, the operation of a part of the plurality of drive units is limited.
That is, the option control unit 40 of the option devices 2-1, 2-2 and 2-3 responds to the drive state of the option devices 2-1, 2-2 and 2-3 and , 2-2, and 2-3, control is performed so that the operation of a part of the drive units mounted on at least one option device is limited and the operation of the drive units mounted on the remaining option devices is maintained. To do.

FIG. 7 is an explanatory diagram showing an example in which three optional devices 2-1, 2-2, 2-3 are connected in cascade to the main device 1.
In FIG. 7, the lift motor 21, the paper feed motor 22, the transport motor 23, and the sensor units 33 and 34 are omitted, but these are mounted on each optional device as in FIG. 2.
Each of the optional devices connected in cascade has a function of conveying the paper in the device itself or the paper conveyed by the lower option device to the upper option device or the main body device 1.
For example, the option device 2-2 has a function of transporting a sheet in its own device or a sheet transported by the lower option device 2-3 to the upper option device 2-1.
Further, the option device 2-1 has a function of transporting the paper in its own device or the paper transported by the lower option device 2-2 to the main body device 1.

Next, the operation will be described.
In the example of FIGS. 6 and 7, three option devices 2-1, 2-2, 2-3 are connected to the main body device 1 as a case where a plurality of option devices are connected to the main body device 1. 8 and 9, in order to make it easy to understand the operation of the present invention, two optional devices 2-1 are assumed when a plurality of optional devices are connected to the main device 1. , 2-2 will be described when connected to the main unit 1.
FIG. 8 is a timing chart showing an example when the drive of the lift motor 21 is not restricted so that the total value of the currents flowing through the option devices 2-1 and 2-2 does not exceed the current upper limit value Ref.
FIG. 9 shows an example in which the drive of the lift motor 21 of the option device 2-2 is restricted so that the total value of the currents flowing through the option devices 2-1 and 2-2 does not exceed the current upper limit value Ref. It is a timing chart which shows.

When the two option devices 2-1 and 2-2 are connected in cascade to the main body device 1, for example, even when the option device 2-1 does not feed the paper 32, the lower option If the device 2-2 is transporting the paper 32, it is necessary to send the paper 32 sent from the lower option device 2-2 to the main body device 1, so it is mounted on the option device 2-1. It is necessary to maintain the driving of the transport motor 23 being present.
That is, when the optional device 2-1 does not feed the paper 32, the optional device 2-1 stops the paper feed motor 22 in its own device, but it is necessary to keep driving the transport motor 23.
For this reason, in the example of FIGS. 8 and 9, the paper feed motor 22 mounted on the option device 2-1 is stopped, but the transport motor 23 mounted on the option device 2-1 During the timing when the paper 32 is sent from the optional device 2-2, the drive is maintained.

The power supply device 11 of the main body device 1 supplies driving power to the option devices 2-1 and 2-2, and supplies driving power to the main body control unit 14 and the like.
When receiving power from the power supply device 11, the main body control unit 14 outputs the current upper limit value Ref to the comparator 13 as in the first embodiment.
However, in the second embodiment, since the two optional devices 2-1 and 2-2 are connected to the main body device 1, a current upper limit larger than the current upper limit value Ref shown in the first embodiment. The value Ref is output to the comparator 13.

Thereafter, the main body control unit 14 transmits a command (CMD) for exerting a desired function to the option device 2.
In the second embodiment, for convenience of explanation, a command (CMD) for instructing the feeding of the paper 32 from the tray 31 and the conveyance of the paper 32 to the main unit 1 is transmitted to the option device 2-2, and the lower side An example in which a command (CMD) instructing conveyance of the paper 32 sent from the optional device 2-2 is transmitted to the optional device 2-1.
The option device 2-2 receives a command (CMD) instructing to feed and transport the paper 32 from the main body control unit 14 of the main body device 1 while receiving power from the power supply device 11 of the main body device 1. In the same manner as the optional device 2 in FIG. 1, the paper feed motor 22 and the transport motor 23 are driven to realize the paper feed and transport of the paper 32.
The option device 2-1 is sent from the lower-side option device 2-2 from the main body control unit 14 of the main body device 1 in a state where power is supplied from the power supply device 11 of the main body device 1. When a command (CMD) for instructing conveyance of the paper 32 is received, the conveyance motor 23 is driven to realize conveyance of the paper 32.

When the power supply device 11 starts supplying power to the optional devices 2-1 and 2-2, the current detection unit 12 of the main device 1 starts from the main device 1 to the optional devices 2-1 and 2-2 as the power is supplied. 2 is detected, and a current detection signal I indicating the total value of the currents is output to the comparator 13.
When the comparator 13 receives the current detection signal I from the current detection unit 12, the comparator 13 compares the total current value indicated by the current detection signal I with the current upper limit value Ref output from the main body control unit 14.
When the total value of the current indicated by the current detection signal I is greater than the current upper limit value Ref, the comparator 13 outputs a current upper limit signal indicating that the total value of the current is greater than the current upper limit value Ref to the optional devices 2-1 and 2-2. -2.

When the option control unit 40 of the option devices 2-1 and 2-2 receives power supply from the power supply device 11, the option control unit 40 obtains the sensing result of the sensor unit 33 in its own device, and the tray 31 moves the option device 2-1 , 2-2, it is determined whether or not it is inserted at a predetermined position.
When the option control unit 40 of the option devices 2-1 and 2-2 determines that the tray 31 is not inserted at a predetermined position of the option devices 2-1 and 2-2, the option control unit 24 of FIG. Similarly, since the paper 32 in the tray 31 cannot be lifted, the lift motor 21 is stopped if the lift motor 21 in the apparatus itself is being driven. If the lift motor 21 is stopped, the lift motor 21 is kept stopped. If the paper feed motor 22 in the apparatus is also being driven, the paper feed motor 22 is stopped, but if the lower option device is carrying the paper 32, the drive of the carry motor 23 is maintained.

When the option control unit 40 of the option devices 2-1 and 2-2 determines that the tray 31 is inserted at a predetermined position of the option devices 2-1 and 2-2, A sensing result is obtained, and it is determined whether or not the paper 32 in the tray 31 has been lifted up to a feedable position.
If the option control unit 40 of the option devices 2-1 and 2-2 has already been lifted up to a position where the paper 32 in the tray 31 can be fed, the option control unit 40, like the option control unit 24 of FIG. Even if the lift motor 21 is stopped, the paper 32 in the tray 31 can be fed, so the lift motor 21 is stopped.

The option control unit 40 of the option device 2-1, 2-2, when the sensor unit 34 in its own device detects that the position of the paper 32 is the lower limit position P _BOT of the paper _feedable position, If the lift motor 21 in the apparatus is stopped, the continuous feeding time of the paper 32 in a state where the lift motor 21 is stopped becomes extremely short. Therefore, as in the first embodiment, For example, when the sensor unit 34 detects that the position of the paper 32 is the upper limit position _PUPP at which paper can be fed, the lift motor 21 in the apparatus itself is stopped. As a result, it is possible to lengthen the continuous feeding time of the paper 32 in a state where the lift motor 21 is stopped.
Here, the lift motor 21 is also controlled for the option control unit 40 of the option device 2-1 that does not feed the paper 32. The reason is that the main body control unit 14 of the main body device 1 supplies the paper 32. This is because when the command (CMD) for instructing paper feeding is received, the paper 32 can be fed immediately.

The option control unit 40 of the option devices 2-1 and 2-2 determines whether or not the current upper limit signal is transmitted from the comparator 13 when the paper 32 in the tray 31 is not lifted up to a feedable position. It is determined whether the total value of the currents flowing through the option devices 2-1 and 2-2 exceeds the current upper limit value Ref.
The option control unit 40 of the option devices 2-1 and 2-2 drives the lift motor 21 when the total value of the currents flowing through the option devices 2-1 and 2-2 does not exceed the current upper limit value Ref. maintain. When the lift motor 21 is stopped, the lift motor 21 is restarted.

When the total value of the currents flowing through the option devices 2-1 and 2-2 exceeds the current upper limit value Ref, the option control unit 40 of the option devices 2-1 and 2-2 In order to save power by suppressing the total value of currents flowing through 2-2 to be equal to or less than the current upper limit value Ref, the lift motor 21 in the apparatus is stopped. When the lift motor 21 is stopped, the lift motor 21 is kept stopped.
In FIG. 9, the drive of the lift motor 21 mounted on the option device 2-1 is maintained, and the lift motor 21 mounted on the option device 2-2 is stopped, whereby the option devices 2-1 and 2- 2 shows an example in which the total value of the currents flowing to 2 is suppressed to be equal to or less than the current upper limit value Ref, but the drive of the lift motor 21 mounted on the option device 2-2 is maintained, and the option device 2-1 is maintained. The total value of the currents flowing through the option devices 2-1 and 2-2 may be suppressed to be equal to or less than the current upper limit value Ref by stopping the lift motor 21 mounted on the device.
Further, by stopping all the lift motors 21 mounted on the option devices 2-1 and 2-2, the total value of the currents flowing through the option devices 2-1 and 2-2 is suppressed to the current upper limit value Ref or less. You may do it.

  At this time, the option control unit 40 of the option device 2-1 receiving the command (CMD) instructing the transport of the paper 32 sent from the lower option device 2-2, the transport motor 23 in the own device. However, since the paper 32 is not fed, the paper feed motor 22 in the apparatus is stopped.

  In the example of FIG. 8, when the lift motor 21 mounted on the option device 2-2 is driven, the total value of the currents flowing in the option devices 2-1 and 2-2 exceeds the current upper limit value Ref. In the example of FIG. 9, when the total value of the currents flowing through the option devices 2-1 and 2-2 exceeds the current upper limit value Ref, the lift motor 21 mounted on the option device 2-2 is immediately stopped. Therefore, the total value of the currents flowing through the option devices 2-1 and 2-2 is suppressed to the current upper limit value Ref or less.

When the option control unit 40 of the option device 2-2 stops the lift motor 21 in its own device, the lift motor 21 stops while the paper feed motor 22 and the transport motor 23 are being driven. To maintain.
The option control unit 40 of the option device 2-2 drives the lift motor 21 in its own device when the paper feed motor 22 or the transport motor 23 stops with the completion of paper feed or transport of the paper 32, for example. There is a possibility that the power consumption has been reduced to the extent that can be achieved. Accordingly, when the stop of the paper feed motor 22 or the conveyance motor 23 is detected, it is determined whether or not the total current value is suppressed to the current upper limit value Ref or less, and the current total value is suppressed to the current upper limit value Ref or less. If so, the lift motor 21 in its own device is restarted.

  As apparent from the above, according to the second embodiment, when the option control unit 40 of the option devices 2-1 and 2-2 receives the current upper limit signal from the comparator 13, the two option devices 2-1 , 2-2, the operation of some of the drive units mounted on at least one of the two option devices 2-1 and 2-2 is restricted, and the remaining option devices Since the operation of the drive unit mounted on the device is maintained, it is possible to save power while suppressing the occurrence of a situation where the functions of the optional devices 2-1 and 2-2 cannot be exhibited. Play.

In the example of FIGS. 6 and 7, three option devices 2-1, 2-2, 2-3 are connected to the main body device 1, and the power supply device 11 of the main body device 1 provides optional driving power. It supplies to the apparatus 2-1, 2-2, 2-3. However, among the optional devices 2-1, 2-2, 2-3, the power supply device 11 of the main device 1 stops the supply of power to the optional device that does not affect the performance even if it is stopped. You may do it.
For example, if the optional device 2-3 has not received a command (CMD) from the main body control unit 14 of the main body device 1 and does not feed or convey the paper 32, the optional device 2-3 Since stopping the function does not affect the performance of the function, the power supply device 11 of the main device 1 may stop supplying power to the option device 2-3.
Thereby, further power saving can be achieved.

Embodiment 3 FIG.
FIG. 10 is a block diagram showing an image forming apparatus according to Embodiment 3 of the present invention. In FIG. 10, the same reference numerals as those in FIGS.
The capacitor 52 is connected between the power supply line 51 that transmits power supplied from the power supply device 11 of the main body device 1 to the optional devices 2-1, 2-2, and 2-3 and the ground.

In the first and second embodiments, when the comparator 13 outputs the current upper limit signal, for example, the lift motor 21 is stopped. However, the comparator 13 detects that the current value exceeds the current upper limit value Ref. Then, since it takes some time until the lift motor 21 is actually stopped, a peak current (current whose current value exceeds the current upper limit value Ref) is generated until the lift motor 21 is stopped. .
Therefore, in the third embodiment, the capacitor 52 is connected between the power supply line 51 and the ground so that the peak current can flow for a few milliseconds.

  The capacitance of the capacitor 52 connected between the power supply line 51 and the ground is determined by the following equation (1).

式（１）において、ＩＰはピーク電流、ＩＬは電源装置１１から出力される規定電流、ｔはピーク電流が流れる期間、ΔＶは許容電圧降下である。

In Expression (1), IP is a peak current, IL is a specified current output from the power supply device 11, t is a period during which the peak current flows, and ΔV is an allowable voltage drop.

For example, when the specified voltage IL output from the power supply 11 is 10 A and a peak current IP of 10.5 A is generated, if a 3000 μF capacitor 52 is connected, an allowable voltage drop ΔV of 0.5 V is 3 milliseconds. During this period, the peak current IP can flow.
Therefore, in this case, for example, by configuring the comparator 13 with a microcomputer or the like, the total value of the currents flowing through the option devices 2-1, 2-2 and 2-3 and the current upper limit value Ref at a cycle of 2 milliseconds at the latest When the current upper limit signal is output from the comparator 13, the lift motor 21 may be stopped within 1 millisecond at the latest.

Embodiment 4 FIG.
In the first to third embodiments, the drive unit that stops the lift motor 21 among the plurality of drive units has been described. However, this is merely an example, and other drive units may be stopped.
FIG. 11 is a top view showing an example in which the option device 2 connected to the main device 1 is a discharge option. In the discharge option, a jogger mechanism 62 is mounted as a drive unit for aligning discharged sheets. A drive unit such as a paper transport motor is also mounted.
In the example of FIG. 11, a jogger mechanism 62 that aligns the discharged sheets is provided with respect to the discharge tray 61 of the option device 2, but when the option device 2 is discharging the sheets, the jogger mechanism 62 is Even if the operation of aligning the discharged paper is stopped, the paper discharge itself can be continued. Therefore, when the current value exceeds the current upper limit value Ref, the jogger mechanism 62 is set as the drive unit to be stopped. It may be selected to stop the jogger mechanism 62. In this case, the operation of the paper transport motor continues.
Also in this case, the same effects as those of the first to third embodiments can be obtained.

  In the fourth embodiment, an example in which the option device 2 is a discharge option is shown, but the option device 2 may be a finisher option. When the option device 2 is a finisher option, when the current value exceeds the current upper limit value Ref, the operation of the sheet transport motor as one drive unit in the finisher option is continued, and other drives mounted in the finisher option. You may make it stop the stable mechanism as a part.

In the fourth embodiment, an example in which the types of the plurality of option devices 2 connected to the main device 1 are the same is shown, but a plurality of option devices 2 of different types are connected, and the plurality of option devices 2 are connected. It is possible that one of the optional devices is stopped and the other optional device is not stopped.
For example, when the optional device 2 includes a tray and a discharge option, the driving unit mounted on the tray may continue to be driven and the jogger mechanism 62 mounted on the discharge option may be stopped.

  DESCRIPTION OF SYMBOLS 1 Main body apparatus, 2,2-1,2-2,2-3 Option apparatus, 11 Power supply device, 12 Current detection part (comparison circuit), 13 Comparator (comparison circuit), 14 Main body control part, 21 Lift motor (drive) Part), 22 paper feed motor (drive part), 23 transport motor (drive part), 24 option control part, 31 tray, 32 paper, 33, 34 sensor part, 35, 36 roller, 40 option control part, 51 power line , 52 condenser, 61 discharge tray, 62 jogger mechanism.

Claims (8)

An optional device equipped with a plurality of drive units;
A main device for supplying driving power to the optional device;
A comparison circuit that detects a current flowing from the main body device to the optional device as the power is supplied, and compares the current value with a preset upper limit value;
If the comparison result of the comparison circuit indicates that the value of the current is greater than the upper limit value, the operation of at least one of the plurality of drive units is continued, and the function of the optional device is continued. An image forming apparatus comprising: an option control unit that restricts an operation of another driving unit among the plurality of driving units while exhibiting the above. A plurality of the optional devices are mounted,
The comparison circuit detects a sum of currents flowing from the main body device to the plurality of option devices as the power is supplied, and compares the sum value of the currents with a preset upper limit value.
If the comparison result of the comparison circuit indicates that the total value of the currents is greater than the upper limit value, the option control unit determines whether the plurality of option devices are in accordance with the driving state of the plurality of option devices. 2. The image forming apparatus according to claim 1, wherein the operation of a part of the drive units mounted on at least one of the option devices is limited, and the operation of the drive units mounted on the remaining option devices is maintained. apparatus.   The image forming apparatus according to claim 2, wherein the main body device stops supplying power to a drive unit of the optional device that does not affect the function of the function even if the main device is stopped. A plurality of optional devices are connected in cascade to the main unit,
3. The image forming apparatus according to claim 2, wherein each of the optional devices has a function of conveying the paper in the device or the paper conveyed by the lower option device to the upper option device or the main device. apparatus. The optional device, as the drive unit, a lift motor that raises the paper in the tray to a paper feeding position;
A paper feed motor that feeds the paper raised to the paper feed position by the lift motor;
A transport motor that transports the paper fed by the paper feed motor,
The option control unit is configured such that when the drive state of the option device is when the paper in the tray is being raised to the paper feed position by the lift motor, the comparison result of the comparison circuit indicates that the current value is the upper limit. 2. The image forming apparatus according to claim 1, wherein the lift motor is stopped if it indicates that the value is larger than the value.   The option control unit, after stopping the lift motor, activates the stopped lift motor if the comparison result of the comparison circuit indicates that the current value is smaller than the upper limit value. The image forming apparatus according to claim 5.   A capacitor is connected between a power supply line for transmitting power supplied from the main unit to the optional device and a ground so that a current having a value larger than the upper limit value can flow temporarily. The image forming apparatus according to claim 1. The comparison circuit is mounted in the main device, and the option control unit is mounted in the option device,
The said comparison circuit in the said main body apparatus transmits the information which shows the said comparison result to the said option control part in the said option apparatus, The any one of Claims 1-7 characterized by the above-mentioned. Image forming apparatus.

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