JP2002287578A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus in which a harness structure is simplified and accuracy of timing control of paper feeding operation is not marred by performing control of parts other than a paper feeding part by a CPU of a main body as before and providing the paper feeding part with a paper feed control CPU to exclusively perform the control of the paper feeding part. SOLUTION: The image forming apparatus is characterized by providing a paper feed control means having the paper feed control CPU to exclusively perform the control of the paper feeding part separately from a main body CPU to perform main control, performing the timing control of start of the paper feeding operation of the paper feeding part by the main body CPU and performing necessary control except the timing control of the start of the paper feeding operation of the paper feeding part by the paper feed control CPU.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus having control means for controlling a paper feeding unit independently of a main body.

[0002]

2. Description of the Related Art Generally, the operation of a paper feeding unit of an image forming apparatus such as a laser printer is complicated, and the number of mechatronic components such as sensors, electromagnetic clutches, and motors required for control tends to increase. is there. Therefore, the number of signals for controlling these mechatronics components is large, and the number of harnesses connecting the main body control unit and the mechatronics components of these paper feeding units becomes enormous.

On the other hand, the main body control section is often arranged at a position distant from the paper supply section due to the layout in the apparatus, so that the voluminous paper supply harness crawls a long distance in the main body apparatus. Become. This causes difficulties in the layout of the harness crawling, and lowers the assemblability and maintainability of the device. EMI also has disadvantages.

Further, since the paper feed timing is very closely related to the timing of the subsequent image forming operation, it is desirable that a series of these controls be performed by the same CPU.
However, when those controls are performed by the same CPU, the work load of the CPU increases. Also, it becomes complicated in terms of software. In addition, since a CPU with high operation performance is required, it is disadvantageous in terms of cost.

Japanese Patent Application Laid-Open No. 8-297436 discloses that each unit in a device is classified as a control unit, each unit has a control CPU, and signals are transmitted through multiplex communication means arranged between the units. An image forming apparatus that performs communication and controls each unit while maintaining control consistency is disclosed.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and controls other than the paper feed unit are performed by the CPU of the main unit as in the past. An object of the present invention is to provide an image forming apparatus that includes a paper feed control CPU that exclusively controls a unit, thereby sharing control and simplifying a control program of the CPU of the main body apparatus.

Further, the main body CPU and the paper feed control CPU are connected only by a general-purpose serial bus and a paper feed trigger signal line, without impairing the timing accuracy of the paper feed operation.
The paper feed start timing is controlled by the CPU of the main unit as before.
It is an object of the present invention to provide an image forming apparatus capable of simplifying the harness by reducing the number of signals between the main body control unit and the sheet feeding unit.

It is another object of the present invention to provide an image forming apparatus capable of easily connecting an optional sheet feeding unit capable of achieving the same effect.

It is another object of the present invention to provide an image forming apparatus which enables multiple connection of optional sheet feeding units.

[0010]

In order to achieve the above object, according to the present invention, a main body CPU for performing main control is provided.
Separately, the main body CPU has a paper feed control unit having a paper feed control CPU dedicated to controlling the paper feed unit. The main body CPU controls the timing of starting the paper feed operation of the paper feed unit.
Is characterized in that control other than the timing control of the start of the sheet feeding operation of the sheet feeding unit is performed.

According to a second aspect of the present invention, in the first aspect of the present invention, the main body CPU and the paper feed control CPU are connected by a bus to transmit and receive data relating to control of the paper feed section. In addition to the bus, a paper feed trigger signal line for controlling the start of the paper feed operation of the paper feed unit is connected to the paper feed unit via an AND gate of the paper feed control means. Enable / disable of paper trigger signal,
The signal line for controlling the paper feeding operation stop of the paper feeding unit is A
The sheet feeding operation of the sheet feeding unit is started / stopped by the input to the ND gate and the output of the AND gate.

According to a third aspect of the present invention, in the second aspect of the present invention, there is provided an optional paper feeding unit additionally connected to the main unit, and an optional paper feeding control CPU for exclusively controlling the optional paper feeding unit. Optional paper feed control means,
The optional paper feed control CPU is connected to the main body CPU through a first connector of the bus, and the paper feed trigger signal line is connected to the optional paper feed through a second connector of the paper feed trigger signal line. The input is input to an AND gate of the control means, and the output of the AND gate is connected to the optional paper feeding section. The main body CPU controls the timing of starting the paper feeding operation of the optional paper feeding section. A signal line for controlling the validity / invalidity of the paper feed trigger signal and the stop of the paper feed operation of the optional paper feed unit is input to the AND gate, and the output of the AND gate starts the paper feed operation of the optional paper feed unit. / Stop is performed, and the optional paper feed control means performs control other than the timing control of the paper feed start of the optional paper feed unit.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the paper feed unit comprising the optional paper feed control means and the optional paper feed section is connected to the bus and the paper feed trigger signal line by the bus and the paper feed trigger. The apparatus further includes a connector capable of connecting a paper feed unit having the same characteristics as the paper feed unit via a signal line, thereby enabling multiple connection of the paper feed units.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the bus is a general-purpose serial bus.

[0015]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing the configuration of the image forming apparatus according to the first embodiment of the present invention. The image forming apparatus (main body apparatus A) is divided into a main body control section a, a paper feed control section b, and a paper feed section c. The main body control unit a has a CPU 1 and controls main units other than the paper feeding unit c. The paper feed control unit b has a CPU 2 that specializes in paper feed unit control, and controls the paper feed unit c. The paper feeding unit c is a unit that performs a paper feeding operation.

The CPU 1 controls the operation of the main unit other than the sheet feeding unit. In addition, timing control for starting sheet feeding is performed.
The CPU 2 exclusively controls the operation of the sheet feeding unit c. The communication line 3 is a general-purpose serial bus (typically an I ² C bus) connecting the CPU 1 and the CPU ² . CPU1 and C
The PU 2 can exchange information with the PU 2 via the communication line 3.

The paper feed trigger signal line 4 is a signal line for transmitting a paper feed trigger signal for controlling start and stop of the paper feed operation, and is output from the CPU 1 to the paper feed controller b.
The CPU 1 starts the sheet feeding operation of the sheet feeding unit c by setting the sheet feeding trigger signal to High, and stops the sheet feeding operation of the sheet feeding unit c by setting the signal to Low.

Reference numeral 5 denotes a first paper feed port of the paper feed section c. 6
Is a second paper feed port of the paper feed unit c. 7 is the first paper feed port 5
Are input / output signal groups connecting various mechatronics components existing in the CPU 2 to the CPU 2. Reference numeral 10 denotes an input / output signal group that connects the CPU 2 to various mechatronic components existing in the second paper feed port 6. This input / output signal does not include only a signal for starting / stopping the sheet feeding operation.

Reference numeral 8 denotes an AND gate. The input terminal of the AND gate 8 is connected to the paper feed trigger signal line 4 and the select signal line 9 from the CPU 2. Reference numeral 9 denotes a signal line for transmitting a select signal for selecting the first paper feed port 5 as a paper feed port, and is output from the CPU 2. AN
START / ST output from the output terminal of D gate 8
The OP signal is a signal for controlling start / stop of the sheet feeding operation of the first sheet feeding port 5. When this signal is High, the sheet feeding operation is started, and when this signal is Low, the sheet feeding operation is stopped.

That is, 2 input to the AND gate 8
START / STO output from AND gate 8 only when two signals 4 and 9 are both High
The P signal becomes High, and the sheet feeding operation from the first sheet feeding port 5 is started. When either one of the two signals 4 and 9 input to the AND gate 8 becomes Low, the START / S output from the AND gate 8 is started.
The TOP signal becomes Low, and the sheet feeding operation from the first sheet feeding port 5 stops.

Reference numeral 11 denotes an AND gate. The input terminal of the AND gate 11 includes a paper feed trigger signal line 4 and a CPU
2 is connected to the output signal line 12. 12 is
A signal line for transmitting a select signal for selecting the second paper feed port 6 as a paper feed port, which is output from the CPU 2.
START output from the output terminal of AND gate 11
The / STOP signal is a signal for controlling start / stop of the sheet feeding operation of the second sheet feeding port 6. This signal is High
To start the sheet feeding operation, and to stop the sheet feeding operation at Low.

Next, an image forming apparatus according to a second embodiment will be described with reference to FIG. In FIG. 2, A is a main unit, and B is an optional sheet feeding unit added to the main unit. A is the same as that in FIG.

In the optional paper feed unit B, d
Is an optional paper feed control unit for controlling the paper feed unit e. “e” is a paper feeding unit in the optional paper feeding unit. In the optional paper feed control unit d, the CPU 13
The operation control of the paper feeding unit e is performed exclusively. The CPU 13 is connected to the communication line 3 via the connector 14.

The communication line 3 has a connector 14 for connecting to the optional sheet feeding unit B. Connector 14
Is a connector 14a provided on the main unit side,
The communication line 3 from the CPU 1 is connected. 14b is a connector provided on the optional paper feed unit side,
The communication line 3 from the CPU 13 is connected. That is, by mating the connectors 14 a and 14 b, the CPU 13 causes the CPU 1 and the C
Communication with PU2 becomes possible.

The paper feed trigger signal line 4 is connected to the main body paper feed controller b.
In addition to the above, it is also connected to the optional paper feed control unit d. The paper feed trigger signal line 4 is connected to the optional paper feed unit B
And a connector 15 for connecting to Connector 15
Is a connector 15a provided on the main unit side,
Reference numeral 15b denotes a connector provided on the optional paper feed control unit side. That is, the connectors 15a and 15b
Are combined, the optional sheet feeding control unit d
It becomes possible to receive a paper feed trigger signal.

Next, an image forming apparatus according to a third embodiment will be described. C is a second additional unit that is further added to the main unit A and the optional sheet feeding unit B.
Optional paper feed unit. Reference numeral 24 denotes a connector for connecting a paper feed control unit of the optional paper feed unit C. Reference numeral 24a denotes a connector on the optional paper feed unit B side, and reference numeral 24b denotes a connector on the optional paper feed unit C side. Reference numeral 25 denotes a connector for connecting the paper feed trigger signal line 4 to the optional paper feed unit C. Reference numeral 25a denotes a connector on the optional paper feeding unit B side, and reference numeral 25b denotes a connector on the optional paper feeding unit C side.

As described above, the optional paper feed units can be multiplex-connected via the connector as needed,
In addition, the configuration does not become complicated.

FIG. 4 is a flowchart showing the operation of the image forming apparatus according to the embodiment of the present invention. FIG. 4-A
5 is a flowchart of a sheet feeding operation control of the CPU 1.
FIG. 4B is a flowchart of the sheet feeding operation control of the CPU 2 or the CPU 13.

In FIG. 4A, first, the operation of the CPU 1 shifts to a process related to paper feeding (step S1). C
PU1 is a communication line 3 for CPU2 and CPU13.
And obtain necessary information on each paper feed unit (a). For example, the presence / absence and type of optional units, the paper size of each paper feed port, the presence / absence of a paper feed cassette for each paper feed port, the remaining amount of paper in each paper feed port, jam information,
Error information (paper feed motor error, paper feed cassette error)
(Step S2).

The CPU 1 checks the information of each sheet feeding unit obtained in step S2 and determines whether there is an error (step S3). If there is an error in step S3, the CPU 1 sends “NOT R” to the controller.
EADY "is transmitted and the content of the error is displayed on the display section, and the process returns to step S2 to loop. This loop is repeated until the error is cleared (step S2).
4). If there is no error in step S3, the CPU 1
“READY” is transmitted to the controller, and “READY” is displayed on the display unit (step S
5).

The CPU 1 receives a print start request from the controller. This request includes designation of a paper feed port and designation of a paper size (step S6).
The CPU 1 sends to the CPU 2 or the CPU 3 according to the content of the print request received from the controller.
The paper feed port is specified through the communication line 3 (b) (step S7). The CPU 1 waits for a response (c) of paper supply start preparation OK for the specified paper supply port from the CPU 2 or CPU 3 via the communication line 3. When the answer of the sheet supply start preparation OK is received, the process proceeds to step S9 (step S9).
8).

The CPU 1 starts a printing operation. C
The PU 1 activates the trigger signal for starting the sheet feeding operation at an appropriate timing (step S9). CPU
1 executes a print operation (step S10). C
PU1 is connected to CPU2 or CPU3 through communication line 3.
Waits for a paper feed stop request (d) from step S11 (step S11). Upon receiving the stop request, the CPU 1
After the trigger signal for starting the sheet feeding operation is deactivated, the process returns to step S2 (step S12).

In FIG. 4B, first, the paper feeding unit is initialized by turning on the power (step S13).
The CPU 2 and the CPU 3 perform a preparatory operation for paper supply for each paper supply unit (that is, check the presence or absence of a paper supply cassette, the remaining amount of paper, the paper size, the presence or absence of a jam, the presence or absence of an error, etc. And raising the bottom plate of the sheet feeding cassette until the sheet feeding surface reaches a predetermined position (step S14). The CPU 2 or the CPU 3 stores the information of each sheet feeding unit obtained in the preparation operation of Step S14,
The data is transmitted to the CPU 1 through the communication line 3 (a) (step S15).

It is checked whether or not there is an error in the information content of each paper feed unit obtained in the preparation operation in step S14. If there is an error, the process proceeds to step S14
And the loop is repeated until all errors are eliminated (step S16). If there is no error in step S16, the CPU 2 or CPU 3 repeats the loop and waits until the CPU 1 receives the designation of the paper feed port in charge through the communication line 3 from the CPU 1 (step S1).
7).

In step S17, when the CPU 2 or the CPU 3 receives the designation of the paper feed port in charge from the CPU 1 through the communication line 3 (b), the CPU 2 or the CPU 3 activates the select signal for the paper feed port (step S1).
8). The CPU 2 or the CPU 3 transmits to the CPU 1 via the communication line 3 that the selection of the designated paper feed port is completed (c) (step S19).

The paper feeding operation is started when a trigger signal for starting the paper feeding operation is activated by the CPU 1. The sheet feeding operation is performed only on the sheet feeding port that satisfies the following two conditions. 1) CPU (CPU2 or CPU3) of paper feed control unit
The paper feed port select signal is active. 2) The trigger signal for starting the sheet feeding operation is activated by the CPU 1.

The CPU of the CPU 2 or CPU 3 whose paper supply port is designated as the paper supply port in charge of itself is C
In response to a paper feed operation started by the PU 1 activating a trigger signal for starting the paper feed operation at an appropriate timing, sensors provided at the paper feed port and the paper passing path are monitored, and the paper feed operation is started. (Step S20).

The CPU 2 or the CPU 3 which has estimated the end timing of the sheet feeding operation in step S20
Switches the select signal of the paper feed port to inactive at the appropriate timing to end the paper feed operation. At this time, the trigger signal for starting the paper feeding operation from the CPU 1 is still active, but the other condition, ie, the select signal is sent to the CPU 2 or
Is deactivated, the actual paper feeding operation ends (step S21).

That is, the start timing of the paper feed operation is managed by the CPU 1 which is the CPU of the main body control unit, and the end timing of the paper feed operation is determined by the CP of the paper feed control unit of the paper feed port.
It is managed by the CPU 2 or CPU 3 which is U.

By switching the select signal to inactive, the CPU 2 or CPU 3 that has completed the paper feeding operation from the paper feeding port transmits a message to the effect that the paper feeding operation has been completed to the CPU 1 through the communication line 3 (d). Then, the process returns to step S14.

The embodiment described above is an example of a preferred embodiment of the present invention, and the present invention is not limited to the embodiment, and various modifications may be made without departing from the scope of the invention. It is possible.

[0043]

As is apparent from the above description, according to the present invention, the control of the paper feeding unit is performed separately from the control of the main body without impairing the precision of the timing control of the paper feeding operation of the paper feeding unit. It can be modularized, and the control program of the CPU of the main body control unit can be simplified.

Further, the number of signals between the main body control section and the sheet feeding section can be reduced to simplify the harness, and the degree of freedom in unit layout can be increased.

Further, the assemblability and maintainability of the apparatus are improved, the development efficiency of the control program is improved, and the reliability of the apparatus is improved and the cost is reduced.

Further, it is possible to connect an additional optional paper feed unit without increasing the number of signals, and to connect multiple optional units to the main unit without complicating the structure and operability. This makes it easy to expand specifications and enhances responsiveness to market demands.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an image forming apparatus according to a second embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration of an image forming apparatus according to a third embodiment of the present invention.

FIG. 4 is a flowchart illustrating an operation of the image forming apparatus according to the embodiment of the present invention.

[Explanation of symbols]

 1 CPU 2 Paper feed control CPU 3 Communication line 4 Paper feed trigger signal line 5 First paper feed port 6 Second paper feed port 7 First paper feed port input / output control line 8 AND gate 9 Select signal line 10 Second paper feed Mouth input / output control line 11 AND gate 12 Select signal line 13 Optional paper feed control CPU 14 Communication line connector 15 Paper feed trigger signal line connector 24 Communication line connector 25 Paper feed trigger signal line connector

Claims (5)

[Claims] 1. A paper supply control means having a paper supply control CPU dedicated to controlling a paper supply unit separately from a main body CPU performing main control, wherein the main body CPU starts a paper supply operation of the paper supply unit. Wherein the sheet feeding control CPU performs control other than the timing control of the start of the sheet feeding operation of the sheet feeding unit. 2. The main body CPU and the paper feed control CPU are connected by a bus and exchange data related to control of a paper feed section. A paper feed trigger signal line for controlling the start of the paper feed operation is connected to a paper feed unit via an AND gate of the paper feed control means, and the paper feed control CPU makes the paper feed trigger signal valid / invalid. And a signal line for controlling the paper feed operation of the paper feed unit is input to the AND gate, and the output of the AND gate starts / stops the paper feed operation of the paper feed unit. Claim 1.
The image forming apparatus as described in the above. 3. An optional paper feeder additionally connected to the main unit, and an optional paper feed controller having an optional paper feed control CPU for exclusively controlling the optional paper feeder, The optional paper feed control CPU is connected to the main body CPU through a first connector of the bus, and the paper feed trigger signal line is connected to the optional paper feed through a second connector of the paper feed trigger signal line. The input is input to an AND gate of the control means, and the output of the AND gate is connected to the optional paper feeding unit. The main body CPU controls the timing of starting the paper feeding operation of the optional paper feeding unit. From the control means, a signal line for controlling the validity / invalidity of the paper feed trigger signal and the stop of the paper feed operation of the optional paper feeder is provided by the AND gate. The optional sheet feeding unit starts / stops the sheet feeding operation of the optional sheet feeding unit by the output of the AND gate. The image forming apparatus according to claim 2, wherein the control is performed. 4. A paper feeding unit comprising said optional paper feeding control means and an optional paper feeding unit, wherein said bus and said paper feeding trigger signal line are connected to said paper feeding unit via said bus and paper feeding trigger signal line. 4. The image forming apparatus according to claim 3, further comprising a connector capable of connecting a paper feed unit having a similar characteristic, wherein the paper feed unit can be multiplexed. 5. The image forming apparatus according to claim 1, wherein the bus is a general-purpose serial bus.