JPH08297436A - Image forming device - Google Patents

Abstract

PURPOSE: To reduce the total costs including the development cost. CONSTITUTION: Devices and individual members in an image forming device are classified according to function and the machine is constituted of multiple units (operational units 301-fixing/paper ejecting unit 310) which are defined as individual units to be controlled, and provided with multiple unit control means (unit control board 301a-310a) provided in each unit of a control unit and a CPU 152 (not illustrated) for unit control for controlling the corresponding units, and a multiplex communication means (communication line 158) provided across the multiple unit control means. And, the multiple control means multiplexes the communication through the multiplex communication means and control the corresponding units, while keeping consistency in controls among the individual control means.

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 such as a copying machine and a printer. More specifically, the apparatus and each member in the machine are classified according to their functions, and a plurality of units are used as one control unit. The present invention relates to an image forming apparatus configured to perform multiplex communication between the plurality of units.

[0002]

2. Description of the Related Art In a conventional image forming apparatus such as a copying machine, all controls are integrated in a main control section, and the main control section directly drives respective units distributed in the machine. It is a composition. In other words, each unit is centrally controlled by one main board on which the main control unit is mounted.

Further, as a conventional technique related to the present invention, there is, for example, "a message transmission system for a copying machine and a copying machine" disclosed in Japanese Patent Laid-Open No. 59-135598. In this device, the wiring space can be reduced by transmitting and receiving control commands between the central processing unit and the remote unit (unit for each copying function) via one shared transmission line.

Further, in the "paper tray stock control system" of Japanese Patent Laid-Open No. 1-145669, the control unique to the intermediate tray is efficiently performed by the intermediate tray module by connecting the main controller and the tray controller by serial communication. This is done so that standardization of programs can be achieved.

Further, the "multiplex transmission device" of Japanese Patent Laid-Open No. 6-189366 discloses an information output means in a multiplex transmission device having an actuator controlled based on information output from information output means such as a sensor and a switch. The communication unit for the actuator and actuator is separated so that the wiring can be shortened, the layout flexibility can be improved, and the increase in the number of failures can be avoided.

[0006]

However, according to the above-mentioned conventional image forming apparatus, when each unit is controlled by one main board on which the main controller is mounted,
The input / output configuration of the main board differs depending on the number and type of units connected, and the main board cannot be used in common among models with different unit configurations. Therefore, it is necessary to design a main board for each model. However, there was a problem that the total cost including the development cost becomes high.

Further, in order to control each unit with one main board, it is necessary to send and receive signals between the main board and each unit, which results in a large input / output section of the main board. As a result, the main board itself is large and there are major restrictions on component layout.

Further, there has been a problem that the amount of connecting wires (electric wires) between the main board and the sensors, actuators, etc. constituting each unit becomes enormous, and the assemblability and serviceability are poor.

Further, since the control of each unit is centralized by one main board, it is not possible to check the operation performance of each unit alone, and it is necessary to connect the main board and other related units. ， There was also a problem that mounting workability was poor.

Further, since the control of each unit is centrally performed on one main board, in other words, the software installed on the main board performs complicated control over each unit, so There are also problems that the design becomes complicated, the development cost rises, and the development takes time.

On the other hand, in the conventional image forming apparatus, it is possible to reduce the amount of connecting lines (electric wires) by achieving multiple communication, but it is possible to control the entire system by simply multiplexing. Because a main board is required,
The above problems caused by the large-sized main board still remain.

[0012] Further, since the control signal amount increases as the copying function improves by simply multiplexing, there is a problem that the communication time is delayed due to the increase in the traffic amount on the communication medium, and further, the communication is delayed. When a process faster than the time is required, it is necessary to directly connect between the main board and the controlled parts, which may not necessarily contribute to the reduction of electric wires.

Further, in the conventional image forming apparatus, since centralized control is performed, even if the sensor information is used only for the processing within the unit, the sensor information is temporarily transmitted from the unit to the main board (main controller). Then, a predetermined calculation is performed on the main board, and the result (part drive output) is transmitted to the corresponding unit to perform the unit operation.
Since it requires a communication time for multiple times, the simple processing cannot be performed quickly, and eventually, in addition to the multiplex communication line, an electric wire that directly connects the main board and each unit is required. was there.

The present invention has been made in view of the above, and aims to reduce the total cost including the development cost, reduce the restrictions on the component layout, reduce the connection dose, and improve the mounting workability. At the same time, it aims to avoid delay of communication time due to increase of traffic on communication medium, facilitate software design, reduce development cost and development time, and reduce additional wires other than multiplex communication wires. To do.

[0015]

In order to achieve the above object, an image forming apparatus according to a first aspect of the present invention is a plurality of image forming apparatuses in which the apparatus and each member in the machine are classified by function, and each is configured as one control unit. Unit and a plurality of unit control means provided in each unit which is the control unit and having a CPU for controlling the corresponding unit, and a multiplex communication means arranged between the plurality of unit control means. And a plurality of unit control means performs multiplex communication of signals via the multiplex communication means to control corresponding units while maintaining control consistency among the respective unit control means. is there.

Further, in the image forming apparatus according to a second aspect of the present invention, among the plurality of units, each unit related to the paper transport system has at least one transport sensor on the transport path of the unit, and the unit is provided. The unit control means therein controls the conveyance based on the operation timing of the conveyance sensor.

Further, in the image forming apparatus according to a third aspect, among the plurality of units, each unit related to image formation has a control timer for performing sequence control,
The unit control means in the unit executes sequence control based on the output value of the control timer.

Further, in the image forming apparatus according to the fourth aspect, the control timers of the respective units related to the image formation simultaneously start measurement by a common signal.

Further, in the image forming apparatus according to a fifth aspect, the common signal is a common operation for each repeat copy, and the operation of the unit that operates first among the units related to the image formation is started. It is a signal indicating timing.

Further, in the image forming apparatus according to the sixth aspect, the common signal is transmitted by a unit in charge of operation display among the plurality of units, and the unit in charge of operation display is a print key. When the transmission timing of the common signal is calculated at the time of receiving the input, the common signal is transmitted to each unit related to the image formation when the transmission timing is reached, and each unit related to the image formation is transmitted. By receiving the common signal,
The control timer of each person is started.

According to a seventh aspect of the present invention, an image forming apparatus controls a common transport path unit through which sheets fed from each unit of the paper feed system pass, and is arranged on the common transport path unit. Transport unit control means having a transport sensor that is provided, the transport unit control means transmits a detection signal to the unit control means of each unit related to the image formation when the transport sensor detects a sheet,
Unit control means of each unit related to the image formation,
Of the common signal and the detection signal, each control timer is started based on the previously received signal.

Further, in the image forming apparatus according to the present invention, among the plurality of units, the unit related to the operation system has operation key means and display means, and unit control of the unit related to the operation system. The means sets the copy mode and the copy start based on the input information of the operation key means and the state information input from each unit,
In addition to displaying on the display means, the copy mode and the start of copying are output to each related unit.

[0023]

According to the image forming apparatus of the present invention (claim 1), signals are multiplexed by a plurality of unit control means provided in each unit which is a control unit and having a CPU for controlling the corresponding unit. Communication is performed to control the corresponding units while maintaining control consistency among the unit control means. Therefore, the main control unit that controls the whole can be deleted.

An image forming apparatus of the present invention (claim 2)
Among the plurality of units, each unit related to the paper transport system has at least one transport sensor on the transport path of the unit, and the transport control is performed based on the operation timing of the transport sensor. The independence of.

An image forming apparatus of the present invention (claim 3)
Of the plurality of units, each unit related to image formation has a control timer for performing sequence control,
By executing the sequence control based on the output value of the control timer, the independence of the unit is enhanced.

Further, the image forming apparatus of the present invention (claim 4).
The control timer of each unit related to image formation starts measurement at the same time with a common signal. Therefore, it is possible to achieve consistency without causing timing deviation between units.

Further, the image forming apparatus of the present invention (claim 5).
Is a common operation for each repeat copy, and a common signal is the operation start timing of the unit that operates first among the units related to image formation. Therefore, sequence control is simplified and bugs are less likely to occur.

Further, the image forming apparatus of the present invention (claim 6).
The unit in charge of the operation display calculates the transmission timing of the common signal when it receives the input of the print key, and when the transmission timing is reached, transmits the common signal to each unit related to the image formation. Then, each unit related to image formation starts its own control timer by receiving a common signal. Therefore, the software load on each unit is reduced, and the amount of software change required when changing the components related to timer start is also reduced.

An image forming apparatus of the present invention (claim 7)
Sends a detection signal to the unit control means of each unit related to image formation when the paper is detected by the conveyance sensor, and the unit control means of each unit related to image formation detects the common signal and the detection signal. Among them, each control timer is started on the basis of the signal received earlier to reduce the deviation between the image position on the paper and the image on the photosensitive drum.

Further, the image forming apparatus of the present invention (claim 8).
Among the plurality of units, the unit related to the operation system sets the copy mode and the copy start on the basis of the input information of the operation key means and the status information input from each unit, and displays the copy mode on the display means. Outputs the copy mode and copy start to each related unit.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A copying machine will be described as an embodiment of the image forming apparatus of the present invention in detail with reference to the drawings.

FIG. 1 is an explanatory view showing the structure of the copying machine of the present embodiment. Reference numeral 101 denotes the copying machine main body for making a copy image, and 102 for conveying the original document to the original reading position. 1 is an automatic document feeder (hereinafter, referred to as ADF), and reference numeral 103 is a bank paper feeding unit which is a paper feeding unit for recording paper.

Here, the copying machine main body 101 includes a photosensitive drum 104 as an image carrier and a charging charger 111 for charging the surface of the photosensitive drum 104 to a predetermined potential.
A scanner 112 for reading an original image from an original placed at a predetermined position and forming an electrostatic latent image on the surface of the photosensitive drum 104; and developing the electrostatic latent image formed on the surface of the photosensitive drum 104 with toner. Developing unit 113 for forming a visible toner image, a transfer unit 115 for transferring the toner image formed on the surface of the photosensitive drum 104 to a recording sheet at a transfer position 114, and the photosensitive drum after the transfer process. Cleaning unit 116 for removing residual toner from the surface 104
An intermediate roller 133 that conveys the recording paper fed from the bank paper feed unit 103 to the transfer position 114, and an intermediate roller 1
33, an intermediate roller sensor 134 for detecting the recording paper that has reached 33, and a recording paper transfer position 11 at a predetermined timing.
4, a registration roller 135 that conveys the recording paper to the recording sheet 4, a registration sensor 136 that detects the recording paper that has reached the registration roller 135, a fixing unit 141 that fixes the toner image transferred onto the recording paper to the recording paper, and a fixing unit. A fixing unit entrance sensor 142 for detecting the recording paper that has reached 141
A branching claw 144 for switching the conveyance direction of the recording paper, a paper ejection roller 145 for ejecting the recording paper to the outside of the machine, and a paper ejection sensor 1 for detecting the recording paper reaching the paper ejection roller 145.
46, a paper ejection tray 147 for placing the recording paper ejected outside the machine by the paper ejection rollers 145, and a recording paper whose surface image formation is completed when images are formed on both sides of the recording paper. And a double-sided tray 150 for storing the.

Further, in this embodiment, the bank paper feeding unit 1
03 is a four-stage paper feed cassette 103 _-1-10_-FourHave
Each paper feed cassette 103_-1-10_-FourTo
Four bank units (bank 1 unit 30
7_-1~ 307_-Four) And control independently.
It

FIG. 2 is an explanatory view showing a schematic structure of the bank unit of the bank paper feeding unit 103. The pressure bottom plate 121 on which the recording paper 120 is placed and the pressure bottom plate 121 for pushing the pressure bottom plate 121 upward. Pressure arm 122 and recording paper 120
To detect the recording paper 120 that has reached the paper feed roller 124, and a pair of paper feed rollers 124 that sends the recording paper 120 taken out by the call roller 123 to the conveyance path. A paper feed sensor 125,
It is composed of a turn roller 131 for transporting the recording paper 120 delivered by the paper feed roller 124 to a transport path common to each bank unit. Although not shown, each bank unit has a raising motor for raising the pressure arm 122, a calling solenoid for moving the calling roller 123, and a pair of paper feeding rollers 124 for contacting and separating from each other. It is equipped with a paper feed clutch and various sensors used for paper feed control.

FIG. 3 is a block diagram showing the construction of the control system of the copying machine, which is the main part of this embodiment. As shown in the figure, the devices and members within the machine are classified according to function, and each is controlled by one control. A plurality of units 301 to 31 configured as a unit
0, and a plurality of unit control plates (unit control means of the present invention) provided in each unit 301 to 310 which is a control unit and having a unit control CPU 152 (see FIG. 4) for controlling the corresponding units. 301a
-310a and a plurality of unit control plates 301a-310
Communication line 158 as a multiplex communication means arranged between a and
And a plurality of unit control plates 301a to 310a
However, multiplex communication of signals is performed via the communication line 158 to control the corresponding units 301 to 310 while maintaining consistency of control among the unit control plates 301a to 310a.

Although the communication line 158 is used as the multiplex communication means in this embodiment, the invention is not limited to this, and radio or optical radio may be used.

In each of the units 301 to 310, the unit control plates 301a to 310a serve as sensors for detecting the state of the self unit and various actuators for operating the respective parts of the self unit, as shown below. It is connected.

Here, the unit control plate 301a of the operation unit 301 is connected with a key input device for the operator to make various settings, a display device for notifying the operator of various messages, and the like.

The unit control plate 302a of the charging unit 302 for controlling the charging unit 111 has a potential sensor for measuring the potential of the photosensitive drum 104, a high voltage power source for applying a voltage to the charging unit 111, and a charging unit for the charging unit 111. A charger cleaner for cleaning is connected.

The unit control plate 303a of the exposure / optical unit 303 for controlling the scanner 112 is
A position switch that detects the position of the optical system, various abnormality detection sensors, a scanner motor, and a halogen lamp are connected.

The unit control plate 304a of the developing unit 304 for controlling the developing unit 113 has a density sensor for measuring the toner density on the photosensitive drum 104 and an agent presence / absence sensor for detecting the toner amount in the developing unit 113. , Development motor, bias power supply, etc. are connected.

Further, a high voltage power source or the like is connected to the unit control plate 305a of the transfer unit 305 which controls the transfer unit 115.

Further, the unit control plate 306a of the cleaning unit 306 for controlling the cleaning section 116.
Includes high-voltage power supply.

Further, the unit control board 307a _-1 ～307A _-4 bank 1 units 307 _-1 to bank 4 units 307 _-4 constituting the bank sheet feeding unit 103, respectively lifting motor, call solenoid, the paper feed clutch , Upper limit sensor, paper feed sensor, paper presence sensor, paper size sensor, bank set sensor, etc. are connected.

Further, the unit control plate 308 of the drum motor unit 308 for controlling the rotation of the photosensitive drum 104.
A drum motor, an encoder and the like are connected to a.

The unit control plate 309a of the transport unit 309 which controls the transport of the recording paper 120 has a paper feed motor, a resist clutch, an intermediate roller sensor,
A resist sensor or the like is connected.

Further, the unit control plate 31 of the fixing / sheet discharging unit 310 for controlling the fixing section 141 and the sheet discharging section.
0a is a fixing motor, a fixing heater, a branch solenoid,
A temperature sensor, a fixing entrance sensor, a paper discharge sensor, etc. are connected.

For simplification of description, in FIG. 3, ten units 301 to 310 are shown as a plurality of units, but in addition, for example, a manual paper feeding unit, a double-sided paper feeding unit, etc. In particular, the unit configuration is not limited to this.

FIG. 4 shows each unit control plate 3 shown in FIG.
It is a block diagram which shows the structure of 01a-310a. Since the unit control plates 301a to 310a have the same configuration, the unit control plate 301a of the operation unit 301 will be described here as an example.

The unit control board 301a sends and receives data to and from the communication CPU 151 for controlling the communication with the other unit control boards 302a to 310a, the unit control CPU 152 for controlling the operation of its own unit, and the communication line 158. Communication port 153 and the ROM 15 in which the control sequence program of the own unit is stored
4, a RAM 155 for storing control data, an input / output port 156 for interfacing with actuators, sensors, etc., an address bus, a data bus and a control bus for connecting the above-mentioned respective parts. It is composed of a bus 157.

In the above structure, the unit control CPU 152 uses the control sequence program stored in the ROM 154 and, if necessary, the RAM 1
55 is used to control the above parts. Further, in this embodiment, the communication CPU 151 and the unit control CPU 15
2 CPUs are used, but a unit control CPU
The number of CPUs may be one, which is also used for communication control at 152.

In FIG. 4, an external unit (here,
From the other unit control boards 302a to 310a) to the communication line 1
The information input to the communication port 153 via 58 is
It is fetched according to the protocol of the communication CPU 151 and stored in the RAM 155. Unit control CPU
A unit 152 checks the external information stored in the RAM 155 or the sensor information from the input / output port 156 according to the program contents stored in the ROM 154, and at the timing designated by the program stored in the ROM 154, the unit 152 Controls actuators (motors, solenoids, etc.) required for operation.

FIG. 5 shows the relationship between the time until the virtual image front end on the surface of the photosensitive drum 104 reaches the transfer position 114 and the time from the start of paper feeding until the recording paper 120 reaches the transfer position 114. FIG.

Here, each time (T1 to T shown in FIG.
8) will be defined. T1: recording paper 120 fed from a designated paper feed cassette (103 _{-1 to} 103 _-4 ) of the bank paper feed unit 103
Is the time until it reaches the position of the paper feed sensor 125 of the corresponding bank unit (307 _{-1 to} 307 _-4 ) and stops. T2: time when the paper feed sensor 125 is stopped. T3: From the position of the paper feed sensor 125 to the intermediate roller sensor 1
Time required to reach the position 34 (value obtained by dividing the paper transport distance from the position of the paper feed sensor 125 to the position of the intermediate roller sensor 134 by the drum linear velocity + rise time of the paper feed clutch).

T4: Time from the position of the intermediate roller sensor 134 to the position of the registration roller 135 (from the position of the intermediate roller sensor 134 to the registration roller 135
Value divided by the linear velocity of the drum). T4 ′: Time required to reach the position of the registration roller 135 from the manual paper feeding position (value obtained by dividing the paper conveyance distance from the manual paper feeding position to the position of the registration roller 135 by the drum linear velocity). T5: Time during which the registration roller 135 is stopped.

T6: Time required to reach the transfer position 114 from the position of the registration roller 135 (registration roller 1
Value obtained by dividing the distance from the position 35 to the transfer position 114 by the linear velocity of the drum + the rise time of the registration clutch) T7: The tip of the virtual image is from the start position to the transfer position 114
(A value obtained by dividing the distance on the drum circumference from the start position of the virtual image front end to the transfer position 114 by the drum linear velocity). T8: Time from when the electrostatic latent image is formed on the surface of the photoconductor drum 104 to when it reaches the transfer position 114.

The copy control operation in the copying machine of the present embodiment having the above configuration will be described in detail in the order of initial setting and copying operation when the power is turned on with reference to the flowcharts of FIGS.

Initial setting when power is turned on When power is turned on, each of the units 301 to 310 sends status information within itself, that is, detection information of various sensors to the operation unit 301 or related units via the communication line 158. At the same time as the transfer, the preparation operation for copying is performed.

Here, the preparatory operation for copying will be described by taking the processing in the bank 1 unit 307 _-1 to bank 4 unit 307 _-4 and the operation unit 301 as an example of the processing which is in a standby state after the power is turned on. The operations of the bank 1 unit 307 _-1 to bank 4 unit 307 _-4 are the same, and only the operation of the bank 1 unit 307 _-1 will be described here.

[0061] Bank 1 unit 307 _-1 of the unit control plate 307a _-1, as shown in the flowchart of FIG. 6,
First, the bank 1 unit 307 _-1 is initialized (S601), and it is determined whether the "copying flag" is ON (S602). The "copying flag" is set to ON in the process of step S621 described later. Therefore, the determination in step S602 is No in the case of the first processing.

Next, bank 1 (paper feed cassette 103 _-1 )
Of the bank 1 set OF (S603), and if not set (S604),
The "F" signal is transmitted to the operation unit 301 (S605),
The check of the set state of bank 1 is repeated (S60
7). On the other hand, if it is set in step S604, the "bank 1 set ON" signal is sent to the operation unit 30.
1 to S1 (S606).

For checking the sensor, the sensor flag is set to a predetermined value in advance when the device is initialized (bank 1 set ON in the above case), and then the actual sensor input is fetched to set the sensor flag. Compared with the setting, only when they do not match, it is determined that the sensor has changed and the actual sensor input value is set in the flag and sent. That is, the sensor flag is reset and the signal is transmitted only when the output value of the sensor changes.

Next, the presence / absence of the recording paper 120 is checked by the paper presence / absence sensor (S608), and depending on the presence / absence of the recording paper 120 (S609), the check result is displayed on the operation unit 30.
1 (S610, S611), and then the paper size (actually, the tray size for accommodating the recording paper 120) is transmitted (S612, S613). If the recording paper 120 stored in the bank is not set to the paper feedable state, recording paper setting processing for setting the paper feedable state is performed, that is, the upper limit sensor is checked (S614). If the upper limit sensor is OFF (S61
5) A signal indicating that the setup is being performed is transmitted to the operation unit 301 (S616), and the recording paper raising motor is driven, and the pressure arm 122 interlocked with the drive is rotated counterclockwise to rotate the pressure bottom plate 121. The recording paper 120 is raised via the, and the upper limit sensor located above is turned on (S
615) to transmit a signal indicating completion of setup to the operation unit 301 (S618), stop the motor,
The recording paper 120 is set at the paper feed position (S619).

Thereafter, it is checked whether or not the copy is started, that is, whether or not the "copy start" signal from the operation unit 301 described later is received (S620).
If the "copy start" signal is received, the "copying flag" is turned on (S621), step S6.
Returning to 02, the copy routine described later (FIG. 10)
Move to. If the "copy start" signal has not been received, the process directly returns to step S602,
The above process is repeated.

Unit control plate 30 of operation unit 301
As shown in FIG. 7, first, the la 1a includes the operation unit 301.
Is initialized (S701), and the "copying flag" is set.
It is determined whether or not is ON (S702). Note that the "copying flag" is turned on in the latter half of this flowchart, and step S702 is No in the first processing.

Next, the information from each unit is input (S
703), neither unit is in setup,
When it is confirmed that there is no abnormality (S704, S
705), and "copyable" is displayed (S706).
On the other hand, one of the units is being set up (S704) or abnormal (S705, S708)
If so, a message to that effect is displayed (S707, S70).
Along with 9), the display of "copy prohibited" is displayed (S71).
0).

Then, the key input for mode setting is checked (S711), and if there is a key input (S71).
2) displays the mode in which there was a key input (S71
3) Then, an instruction is transmitted to cause the unit corresponding to the mode to perform the setting for the mode (S714). It should be noted that each unit performs an operation for preparing a copy based on the transmitted instruction.

For example, when the copy magnification is designated as 71%, a display to that effect is displayed, and at the same time, an instruction for setting the magnification of 71% is transmitted to the exposure / optical unit 303, and the exposure / optical unit 303 displays When the instruction is received, the variable power lens is moved to the specified position and turned on during setup.
Is transmitted to the operation unit.

In the copy-enabled state (S71
5) If there is a print key input (S716), the "copying" flag is set (ON) (S717), the process returns to step S702, and thereafter, the process proceeds to a copying process routine (FIG. 8) described later.

Copy Operation Next, copy operation control will be described. The copy operation control is performed by two sequence processes of image forming control and paper feed / conveyance control.

[Image Forming Control] First, the charging charger 111
, The surface of the photosensitive drum 104 is charged to a predetermined potential in advance, the original is read by the scanner 112,
The surface of the charged photosensitive drum 104 is exposed to form an electrostatic latent image on the surface of the photosensitive drum 104. The electrostatic latent image is visualized by the developing unit 113, and a toner image is formed on the surface of the photosensitive drum 104. The toner image is transferred to the recording paper 120 by the transfer unit 115, and the toner image on the recording paper 120 is fixed by the fixing unit 141. The residual toner on the surface of the photosensitive drum 104 after the transfer process is removed by the cleaning unit 116.
Are removed by and the process moves to the next step. The control of the process is image formation control.

Each unit of the image forming system (302, 303, 3
Nos. 04, 305, 308, and 310) are provided with a control timer that starts at the operation timing of the first member to be operated for image formation (the tip of the virtual image), and the timing control is performed by the timer.

On the other hand, each unit (30
7 _{-1 to} 307 _-4 , 309) has a recording paper sensor (paper feed sensor or registration sensor) on the transport path of each unit, and each unit has a control timer based on the sensor operation. The timing is controlled.

Next, the relationship between the image forming control and the sheet feeding / conveying control will be described. In order to make the visible image formed on the photosensitive drum 104 and the recording sheet 120 coincide with each other at the transfer position 114, the front end of the virtual image is started after a predetermined time (Tx) has passed from the start of sheet feeding.

The leading end of the recording paper 120 fed from the paper feed port of the designated bank (paper feed cassette) is transferred to the transfer position 114.
Ta is the time until the virtual image tip reaches the transfer position 114 from the start position (the drum circumferential velocity is the distance from the start position of the virtual image tip to the transfer position 114 on the drum circumference). Divided value) T
7, the predetermined time (Tx) is Tx = Ta−T
It can be represented by 7.

Transfer from the time when the leading edge of the recording paper 120 fed from the paper feed port of any bank (paper feed cassette) passes through the transport sensor arranged on the transport path common to each paper feed port. When the time required to reach the position 114 is Tb, the predetermined time (Tx ') based on the time when the transport sensor passes can be expressed as Tx' = Tb-T7.

The above relationship is influenced by the layout of the paper feed / transport system of the machine. That is, the transport path conditions described below are satisfied.

When Tx '> 0, the fed recording paper 120 is a sensor for the common conveyance path (intermediate roller sensor 13
After passing 4), the transport control timer outputs the "image forming start" signal at Tx '.

When Tx '<0, Tx> 0 or when there is no sensor (intermediate roller sensor 134) for the common conveyance path, the operation unit control timer is set at the time Tx according to the selected paper feeding unit. The operation unit 301 outputs the "image formation start" signal.

When Tx <0, the operation unit 301 outputs the "image forming start" signal at the copy start time.

In the case of the present embodiment, Ta and Tb are expressed by using T1 to T6 shown in FIG. It is T4 '+ T5 + T6.

The double-sided tray 150 and the bank paper feed unit 103 in this embodiment have the intermediate roller sensor 134 on the common conveyance path, and the T of the above-mentioned conveyance path condition is satisfied.
Since it corresponds to the case of x ′> 0, the transport unit 309
Outputs an "image forming start" signal to each unit of the image forming system when the transport control timer reaches Tx 'after the leading edge of the recording paper 120 passes through the intermediate roller sensor 134.

Further, in the case of manual feeding, since it corresponds to the case of Tx '<0, Tx> 0 of the above-mentioned conveyance path condition, the manual feeding unit feeds the paper feed control timer from the start of feeding to Tx. It outputs the "imaging start" signal to each unit of the imaging system.

Here, the operation of each unit for the image formation control will be specifically described. First, the operation unit control will be described with reference to the flowchart in FIG.

[Control of Operation Unit] When the processing of the standby routine shown in FIG. 7 is shifted to the processing routine during copying shown in FIG. 8, the unit control plate 301a of the operation unit 301 is
First, a "copy start" signal is sent to a related unit such as a drive or bank (S801), and a control timer is started (S802). Next, the above-mentioned image forming start timing is calculated on condition that the designated paper feeding unit is manually fed (S803), and when the calculated timing is reached (S804), an "image forming start" signal is sent to the image forming system. It transmits to each unit (S805).

Thereafter, while waiting for the next copy timing (repeat timing) while checking whether the copy is completed or whether there is an abnormal input from each unit (S).
806-S808). When the next copy timing is reached, the process returns to step S801 to repeat the above process (S
806).

On the other hand, when the copying is completed (S80
7) Or, when an abnormality occurs in any unit (S808), the "copying flag" and the control timer are turned off (S809, S810), and
The process returns to the waiting routine shown in.

[Drive Unit Control] Drum Motor Unit 30
When the unit control board 308a of No. 8 receives the "copy start" signal via the communication line 158, it starts driving the drum motor. At the end of the repeat copy, the drive of the drum motor is stopped slightly after the trailing edge of the virtual image passes through the cleaning unit 116.

[Control of Charging Unit] When the unit control plate 302a of the charging unit 302 receives a "copy start" signal via the communication line 158, it starts an internal control timer to set a predetermined timing (the end of the virtual image). The charging high-voltage power supply is turned on at the timing when the charge reaches the entrance of the charging charger 111), and the high-voltage power supply is turned off after the trailing edge of the virtual image in consideration of the recording paper size passes through the charging charger 111.

[Exposure Control] Exposure / Optical Unit 303
When the unit control plate 303a receives the "copy start" signal via the communication line 158, it starts the internal control timer and simultaneously turns on the halogen lamp for exposure to project the leading edge of the virtual image and the original document. The scanner 112 is started at a timing such that the leading edge of the image coincides with the exposure slit portion. As will be described in detail later, since the scanner 112 is position-controlled by a servo motor, it is possible to know the timing at which the scanner 112 reaches the exposure position regardless of the rise time variation. As the “position timing” signal, as shown by the signal line 159 in FIG. 3, the transport unit 309 is directly transmitted without passing through the communication line 158.
Is output to adjust the re-feed timing of the recording paper 120 to maintain the consistency of the entire apparatus.

[Developing Unit Control] As shown in FIG. 9, the unit control plate 304a of the developing unit 304 first initializes the developing unit 304 (S901), and based on the mode setting instruction from the operation unit 301. Then, it is checked whether or not there is a change in the density set value input (S90
2) If there is a change, a bias corresponding to the set value is set (S903).

Waiting for a "copy start" signal from the operation unit 301 (S904), and via the communication line 158,
When the "copy start" signal is received, the internal control timer is started (S905). After that, when the leading edge of the virtual image reaches the development driving timing, that is, slightly before (with a margin) reaching the position of the developing unit 113 (S906), the motor for driving the developing roller is driven (S907). A bias is applied to the developing roller (S908). At this time, since the development processing time differs depending on the recording paper size (image formation image size), the development OFF timing corresponding to the recording paper size is set (S
909).

While waiting for the timing set above, it is checked whether or not an abnormality has occurred in another unit and whether or not an abnormality has occurred in the developing unit 304 (S910, S911), If there is an abnormality in the developing unit 304 (S912), the details of the abnormality are transmitted to the related unit (S913). Further, if there is any abnormality, it is checked whether or not it is an A abnormality (that is, an abnormality in which the copy operation must be interrupted) (S914). The bias to the developing roller is turned off (S915, S9
16) and returns to step S902. Note that step S9
The waiting routine is composed of 02 to S904.

With no abnormality, the load, that is, the developing motor and the developing roller are turned off shortly after the rear end of the virtual image has passed the transfer position 114 (development OFF timing) (S915, S916). ), And returns to step S902. In this case, if the driving of the developing roller is stopped during the transfer process, transfer blurring occurs, so the driving of the developing roller is stopped after the completion of the transfer.

[Transfer Section Control] When the unit control plate 305a of the transfer unit 305 receives a "copy start" signal via the communication line 158, it starts an internal control timer and, like the developing unit 304, a virtual image. The transfer charger is turned on at the timing when the front end reaches slightly before the transfer position 114, and turned off at the timing when the rear end of the virtual image passes the transfer portion.

[Control of Cleaning Section] The unit control plate 306a of the cleaning unit 306 is provided with the communication line 158.
When a "copy start" signal is received via the, the internal control timer is started, and at the same time, the cleaning blade of the cleaning unit 116 is set, and the timing of the timing when the trailing edge of the virtual image at the end of the repeat passes the cleaning unit 116. Release it a little later.

[Paper feeding control] Bank 1 unit 307
_-1 to bank 4 unit 307 _-4 have similar operations, and here, bank 1 unit 307 _-1
Only the operation of will be described.

[0099] Bank 1 unit 307 _-1 of the unit control plate 307a _-1, upon transition to the copy routine shown in FIG. 10 from the process wait routine shown in FIG. 6, receives the "copy start" signal, the feed The control timer for control is started (S1001), and the calling solenoid and the paper feed clutch are turned on (S1002, S1).
003) so that the calling roller 123 and the paper feeding roller 12
4 is driven to feed the recording paper 120 (preliminary feeding).

The recording paper 120 fed is the paper feeding roller 12
4 and the turn roller 131 are turned on (S1004), the calling solenoid and the paper feed clutch are turned off (S1005).
(S1006), the recording paper 120 is temporarily stopped at that position. As a result, the leading ends of the recording papers 120 that are scattered and set can be aligned at a predetermined position.

On the other hand, in step S1004, the paper feed sensor 1
If 25 is OFF, it is checked whether or not there is an abnormal input until it is turned ON (S1007). If there is an abnormal input, the calling solenoid and the paper feed clutch are turned OFF (S1008, S1009). , And returns to the standby routine shown in FIG.

Subsequently, the control timer started in step S1001 indicates the refeed timing, that is, as shown in FIG.
When the time T (= T1 + T2) shown in is reached (S1
010), the paper feeding clutch is turned on again, and the recording paper 120 is re-fed (main paper feeding) (S1011).

If the control timer does not reach T (= T1 + T2) in step S1010, it is checked whether or not there is an abnormal input until it reaches T (= T1 + T2) (S101).
2) If there is an abnormal input, the calling solenoid and the paper feed clutch are turned off (S1008, S100).
9) and returns to the standby routine shown in FIG.

The re-fed recording paper 120 is taken over by the turn roller 131 on the main body side and conveyed toward the transfer position 114 through the vertical conveyance path. At this time, if the intermediate roller sensor 134 is not ON (S1013), it is checked whether there is an abnormal input (S1014),
If there is an abnormal input, the calling solenoid and the paper feed clutch are turned off (S1008, S1009),
The procedure returns to the standby routine shown in FIG.

On the other hand, if there is no abnormal input, it is judged whether or not there is a jam timing, that is, the control timer started in step S1001 has time T '(= T1 shown in FIG.
It is checked whether or not + T2 + T3 + margin time has elapsed (S1015), and time T '(= T1 + T2 + T3 +)
If the ON signal of the intermediate roller sensor 134 is not received from the transport unit 309 even after the allowance time),
A "bank 1 paper feed jam" (or "bank 2 paper feed jam", "bank 3 paper feed jam", "bank 4 paper feed jam") signal is transmitted to the relevant unit (S1016), and the above-mentioned calling solenoid and the feed solenoid are supplied. Turn off the paper clutch (S
1008, S1009), and returns to the standby routine shown in FIG.

As the related units for transmitting the "bank 1 paper feed jam" signal, there are, for example, the drum motor unit 308, the fixing / paper discharge unit 310, and the like.
The drum motor unit 308 stops the drum motor, and the fixing / paper discharge unit 310 turns off the heater. Similarly, the other related units also stop the dangerous drive.

When the trailing edge of the recording paper 120 passes the paper feed sensor 125, that is, when the paper feed sensor 125 is turned off (S1017), the calling solenoid and the paper feed clutch are turned off (S1008, S100).
9), the control timer started in step S1001 is reset (S1019), and the paper feeding operation in the bank 1 units 307 _{-1 to} 307 _-4 is completed.
The process returns to the waiting routine shown in.

Until the paper feed sensor 125 is turned off, it is checked whether or not there is an abnormal input (S10).
18) If there is an abnormal input, the calling solenoid and the paper feed clutch are turned off (S1008, S10).
09), and returns to the standby routine shown in FIG.

[Control of Transporting Unit] As shown in FIG. 11, the unit control plate 309a of the transporting unit 309 first initializes the transporting unit 309 (S1101),
When a “copy start” signal is received from the operation unit 301 via the communication line 158 (S1102), paper feeding /
The transport motor is driven to drive each transport roller in the vertical transport path including the turn roller 131 (S1103).

As a result, the fed recording paper 120 is transported to the transfer position 114 by each transport roller, and is provided in the vicinity of the intermediate roller 133 arranged on the route after the transport routes of the respective banks merge. When the intermediate roller sensor 134 is reached and the intermediate roller sensor 134 is turned on (S1
104), the control timer 1 inside the unit control plate 309a is started (S1105), and each paper feeding unit (bank 1 units 307 _{-1 to} 307 _-4 , manual paper feeding unit, double-sided paper feeding unit, etc.) The "intermediate roller sensor ON" signal is transmitted (S1106).

Until the intermediate roller sensor 134 is turned on, it is checked whether or not there is an abnormal input (S
1107), if there is an abnormal input, the paper feed / conveyance motor is turned off (S1108), and the process shown in the flowchart of FIG.

After that, the control timer 1 started at step S1105 is Tb (= T4 + T5 + T6-T7).
Is reached, that is, at the image formation timing (S110
9) The "image forming start" signal is transmitted to each unit of the image forming system (S1110).

Subsequently, until the registration sensor 136 is turned on (S1111), it is checked whether there is an abnormal input (S1112). If there is an abnormal input, the paper feed / conveyance motor is turned off. (S1108), the process proceeds to the process shown in the flowchart of FIG. 12 described later.

On the other hand, if there is no abnormal input in step S1112, it is judged whether or not there is a jam timing, that is, the control timer 1 started in step S1105 reaches T4 (intermediate roller sensor 134 reaches registration sensor 136) shown in FIG. It is determined whether or not it is within the time until the jam time) + margin time (S1113), and if it is a jam timing, that is, if the control timer 1 exceeds T4 + margin time, the feeding is performed as a jam of the transport unit. paper/
The conveyance motor is turned off (S1108), and at the same time, a "paper feed conveyance jam" signal is transmitted to the related unit (S1).
114), and proceeds to the processing shown in the flowchart of FIG. 12 described later. It should be noted that, when the related unit receives the "paper feed / jam jam" signal, it stops driving due to danger.

When the recording paper 120 passing through the intermediate roller 133 reaches the registration roller 135, the registration roller 135 is stopped. Therefore, the recording paper 120 is stopped in a state of hitting between the rollers and looped. To form a slack.

On the other hand, the above-mentioned exposure / optical unit 303
When the "exposure position timing" signal output from is directly input (S1115), the process proceeds to step S1117 shown in FIG.

It should be noted that until the "exposure position timing" signal is input (S1115), it is checked whether or not there is an abnormal input (S1116). If there is an abnormal input, the flow chart of FIG. Proceed to the processing shown.

In FIG. 12, in step S1117, the control timer 2 inside the unit control plate 309a is started, and a predetermined time from this point, that is, the time T8 until the leading edge of the exposure image reaches the transfer position 114 (see FIG. 5). ) And the time T6 (see FIG. 5) until the leading edge of the recording paper 120 restarted from the registration roller 135 reaches the transfer position 114 (T8-T6), the registration clutch is turned on (T8-T6). S1118) The registration roller 135 is driven to re-feed the recording paper 120 stopped at the position of the registration roller 135. Here, the recording paper 120 re-fed by turning on the registration clutch is sent to the transfer position 114 by the transfer belt of the transfer unit 115, and after the visible image on the photosensitive drum 104 is transferred to a predetermined position, It is sent to the fixing unit 141.

Next, based on the instruction input from the operation unit 301 (the instruction transmitted in step S714 in FIG. 7), the development OFF timing corresponding to the paper size is set (S1119), and the trailing edge of the recording paper 120 is set. Determines whether the intermediate roller sensor 134 is turned off (S112).
0), if it is OFF, it is determined whether it is the final repeat (S1121). Here, in the case of the final repeat, the paper feed / conveyance motor is stopped after a predetermined time (time for the trailing edge of the recording paper to pass the intermediate roller sensor 134 + margin time) has elapsed since the control timer 1 started ( S1
122) and the control timer 1 is turned off (S11
23) and proceeds to step S1124.

If the intermediate roller sensor is not OFF in step S1120 and if it is not the final repeat in step S1121, the flow advances to step S1124.

In step S1124, it is determined whether the "fixing entrance sensor ON" signal (the signal transmitted in step S1306 in FIG. 13) has been received. If it has been received, the process proceeds to step S1129. If it has not been received, the transfer jam timing is determined (S112).
5). Here, the determination of the transfer jam timing means that a predetermined time (a value obtained by dividing the distance between the registration roller 135 and the fixing entrance sensor 142 by the drum linear velocity + a margin time) has elapsed since the position of the registration roller 135 was started. If the “fixing sensor ON” signal is not received within the transfer jam timing, the “transfer portion jam” signal is transmitted to the related unit as the transfer portion jam (S1126). It proceeds to step S1127.

When the "fixing sensor ON" signal is received and within the transfer jam timing, the resist OFF timing (after the trailing edge of the recording sheet passes the intermediate roller sensor 134 + the margin time). When it reaches (S1129), the registration clutch and the control timer 2 are turned off (S1127, S1128).

Until the registration OFF timing, it is checked whether or not there is an abnormal input (S
1130), if there is an abnormal input, the registration clutch and control timer 2 are turned off (S112).
7, S1128), if there is no abnormal input, it is checked whether or not there is a jam timing (S1131), and in the case of a jam timing, that is, the time when the trailing edge of the recording paper 120 passes the registration sensor 136 + the margin time. If the registration sensor 136 is not turned off even after the elapse, a registration jam occurs and the registration clutch and the control timer 2 are turned off (S1127, S11).
Along with 28), the “registration section jam” signal is transmitted to the related unit (S1132).

[Fixing / Discharging Unit Control] As shown in FIG. 13, the unit control plate 310a of the fixing / discharging unit 310 first initializes the fixing / discharging unit 310 (S1301), and then performs communication. When the "copy start" signal is received from the operation unit 301 via the line 158 (S
1302), the fixing motor and the fixing heater are turned on to drive the fixing / paper discharging conveyance roller (S1303).

When the recording paper 120 reaches the fixing unit 141, and the fixing unit entrance sensor 142 provided near the entrance of the fixing unit 141 is turned on (S1304), the fixing unit control timer is started (S1305) and is conveyed. A "fixing sensor ON" signal is transmitted to the unit 309 (S1).
306).

Until the fixing unit entrance sensor 142 is turned on, it is checked whether or not there is an abnormal input (S
1307) If there is an abnormal input, the fixing motor and fixing heater are turned off (S1308), and the process returns to step S1302.

The leading edge of the recording paper 120 that has passed through the fixing section 141 is conveyed to the position of the branch claw 144. Here, the unit control plate 310a turns on the branch solenoid to turn on the branch claw 14 when the copy mode is the double-sided mode and the front side copy (hereinafter referred to as the double-sided table mode) is being processed.
4 is operated (S1309, S1310), and the recording paper 12
0 is conveyed to the double-sided tray 150.

On the other hand, when it is determined in step S1309 that the mode is not the double-sided printing mode, the recording paper 120 is conveyed to the paper discharge tray 147 and passes through the paper discharge sensor 146 arranged near the paper discharge roller 145. , Output tray 1 outside the machine
It is discharged to 47. At this time, after the control timer is started, if the discharge sensor 146 does not turn on even after a predetermined time, that is, the time for the trailing edge of the recording paper 120 to reach the discharge sensor 146 + the margin time, the fixing is performed. As a jam (S1311, S1312), the “fixing jam” signal is transmitted to the related unit (S131).
3) Turn off the fixing motor and fixing heater (S1
308) and the process returns to step S1302.

A predetermined time after the control timer is started, that is, the trailing edge of the recording paper 120 is at the discharge sensor 1
It is checked whether or not the time for passing 46 plus the allowance time has passed (S1314). If the time has not passed, that is, if it is not the discharge sensor OFF timing, it is determined whether there is an abnormal input (S1315). ), If there is no abnormal input, it is again determined whether the paper discharge sensor 146 is ON (S1316). Here, if the paper discharge sensor is ON,
Returning to step S1311, if not ON, a "paper ejection jam" signal is sent to the related unit as a paper ejection jam (S1317), the fixing motor and the fixing heater are turned off (S1308), and the processing returns to step S1302.

Even if there is an abnormality in step S1315, the fixing motor and fixing heater are turned off (S
1308) and the process returns to step S1302.

On the other hand, in step S1314, if the predetermined time has elapsed, that is, if the discharge sensor is off, the control timer is turned off (S1318). If it is the final repeat, the fixing motor and fixing heater are turned on.
The FF is set (S1308), the driving of the fixing roller and the discharge roller 145 is stopped, and the process returns to step S1302.

As described above, in this embodiment, the main board requiring a new design for each model is eliminated, and the total cost including the development cost is reduced.

Further, since there is no main control board having a large area, the in-machine layout becomes easy.

Moreover, the amount of connecting wires (electric wires) between the main control board and the sensors, actuators, etc. of each unit is reduced, and the assembling property and serviceability are improved.

Further, since the control of the functional operation is shared by each unit, a complicated control software configuration extending between the units is eliminated and software design is facilitated.

Further, as compared with the centralized control type multiplex communication via the main control board, the control of the functional operation is shared by each unit, so that the amount of signal traffic on the communication medium can be reduced and the communication time can be reduced. You can prevent troubles caused by delays.
Further, in this embodiment, since the sensor information is processed in the unit, it can be directly processed without using a communication line, and an additional electric wire is not required.

Further, in order to control the sheet conveyance of the self unit based on the conveyance sensor provided on the conveyance path of each unit,
Units have high independence and do not affect other units even if changes in the unit occur (side effects on control are unlikely to occur).

With respect to the image forming control system, since a control timer is provided for each unit to control its own unit, the unit is highly independent and changes in the unit do not affect other units (control The above side effects are unlikely to occur).

Since the sequence control timer of each unit has a common start point for each unit, no timing deviation occurs between the units (the specific timing of the adjacent upstream unit in the image forming process is set as the start timing of the next unit). In the case of such a timing configuration, if there is a change that shifts the position of a certain unit, it is necessary to change all the timings of the units located downstream thereafter.

The timer start of each unit is an operation point for image formation common to the repeat copy, and does not include the pre-copy preliminary operation and the paper feed start which are necessary only in the copy sequence of the first sheet. Sequence control is simplified and bugs are less likely to occur.

The timer start of each unit is not calculated independently by each unit, but when the operation unit that inputs the print key inputs the same key, the drum virtual image leading edge position is calculated, and the start is the paper feed timing. If it is slower than the above, after waiting for a predetermined time after the paper feed is started, an "image formation start" signal is sent to each unit, and each unit receives that signal and starts the control timer of its own unit, so the software burden on each unit There is also a small amount of software changes when changing the components related to timer start.

When the start of image formation is later than the passage of the sensor on the common conveyance path from the plurality of paper feed ports, the "image formation start" signal is transmitted to each unit at a timing based on the sensor on the common conveyance path. As a result, the misalignment between the image position on the recording paper and the drum becomes small, and the registration management is easy (the waiting time accuracy at the registration part for matching the image at the transfer position and the recording paper position is high, and the slack It becomes easy to manage the quantity). Further, since the positions of the plurality of paper feed ports become irrelevant, the control software can be simplified and the software of each paper feed unit can be made common.

The operation unit inputs the key information and the status information from each unit, sets the copy mode, and directly transmits to each unit without passing through the main control unit or the like, so that the transfer efficiency is improved and the delay of the communication speed is reduced. be able to.

[0144]

As described above, according to the image forming apparatus of the present invention (Claim 1), the CPU is provided in each unit which is a control unit and has the CPU which controls the corresponding unit. By multiple unit control means,
Since the corresponding units are controlled while maintaining the consistency of control among the unit control means by performing multiplex communication of signals, it is possible to delete the main control unit that controls the entire unit, and the total cost including development costs is included. The cost can be reduced. It also reduces the restrictions on component layout,
The connection dose is reduced to improve the installation workability, the delay of the communication time due to the increase of the traffic volume on the communication medium is avoided, the software design is facilitated, the development cost and the development time are reduced, and the multiple communication line is provided. It is possible to reduce additional wires other than the above.

An image forming apparatus of the present invention (claim 2)
According to the method, each of the plurality of units related to the paper transport system has at least one transport sensor on the transport path of the unit, and performs transport control based on the operation timing of the transport sensor. ， Since the independence of the unit is enhanced, even if a change in the unit occurs, it does not affect other units.

An image forming apparatus of the present invention (claim 3)
According to the above, among the plurality of units, each unit related to image formation has a control timer for performing sequence control, and by performing sequence control based on the output value of the control timer, the units are independent. As a result, changes in the unit will not affect other units.

Further, the image forming apparatus of the present invention (claim 4).
According to the method, since the control timers of the units related to image formation start measurement at the same time with a common signal, it is possible to achieve consistency without causing timing deviation between the units.

The image forming apparatus of the present invention (claim 5).
According to the above, since the common signal is the operation common to each repeat copy and the operation start timing of the unit that operates first among the units related to image formation is used as the common signal, sequence control is simplified and a bug occurs. Hard to do.

Further, the image forming apparatus of the present invention (claim 6).
According to the above, the unit in charge of operation display calculates the transmission timing of the common signal at the time of receiving the input of the print key, and at the time of reaching the transmission timing, the unit related to the image formation of the common signal. Each unit related to image formation receives a common signal to start its own control timer, which reduces the software load on each unit and changes the components related to timer start. The amount of software changes with time is also reduced.

Further, the image forming apparatus of the present invention (claim 7).
According to the paper, when a sheet is detected by the conveyance sensor, a detection signal is transmitted to the unit control means of each unit related to image formation, and the unit control means of each unit related to image formation is
By starting the control timer of each one based on the signal received first among the common signal and the detection signal,
Since the misalignment between the paper and the image position on the photosensitive drum is reduced, registration management becomes easy. Further, the positions of a plurality of paper feed ports can be controlled independently of each other, so that the control software can be simplified and the software of each paper feed unit can be shared.

Further, the image forming apparatus of the present invention (claim 8).
According to this, among the plurality of units, the unit related to the operation system sets the copy mode and the copy start based on the input information of the operation key means and the state information input from each unit, and causes the display means to display the copy mode and the copy start. At the same time, by outputting the copy mode and the start of copying to the related units, the data is directly transmitted to each unit without going through the main control unit, etc., so that it is possible to improve the transfer efficiency and reduce the delay in the communication speed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the configuration of a copying machine of this embodiment.

FIG. 2 is an explanatory diagram showing a schematic configuration of a bank unit in a bank paper feeding unit.

FIG. 3 is a block diagram showing a configuration of a control system of a copying machine, which is a main part of this embodiment.

FIG. 4 is a block diagram showing a configuration of each unit control plate shown in FIG.

FIG. 5 is an explanatory diagram showing the relationship between the time until the virtual image front end on the surface of the photosensitive drum reaches the transfer position and the time from the start of paper feeding until the recording paper reaches the transfer position.

FIG. 6 is a flowchart showing a control operation in the initial setting of the bank 1 unit.

FIG. 7 is a flowchart showing a control operation in the initial setting of the operation unit.

FIG. 8 is a flowchart showing a control operation in a copy operation of the operation unit.

FIG. 9 is a flowchart showing a control operation in the copying operation of the developing unit.

FIG. 10 is a flowchart showing a control operation in a copy operation of one bank unit.

FIG. 11 is a flowchart showing a control operation in the copy operation of the transport unit.

FIG. 12 is a flowchart showing a control operation in a copy operation of the transport unit.

FIG. 13 is a flowchart showing a control operation in a copy operation of the fixing / paper discharge unit.

[Explanation of symbols]

125 Paper Feed Sensor 134 Intermediate Roller Sensor 136 Registration Sensor 142 Fixing Port Entrance Sensor 146 Paper Ejection Sensor 152 Unit Control CPU 158 Communication Line 301 Operation Unit 302 Charging Unit 303 Exposure / Optical Unit 304 Developing Unit 305 Transfer Unit 306 Cleaning Unit 308 Drum Motor unit 307 _{-1 to} 307 _-4 bank 1 unit to bank 4 unit 309 transport unit 310 fixing /
Paper discharge units 301a to 310a Unit control plate

Claims (8)

[Claims] 1. An apparatus and each member in an aircraft are classified according to their functions, and a plurality of units each configured as one control unit are provided, and each unit serving as the control unit is provided with control of a corresponding unit. CPU in charge
A plurality of unit control means and a multiplex communication means arranged between the plurality of unit control means, wherein the plurality of unit control means perform multiplex communication of signals via the multiplex communication means. The image forming apparatus is characterized in that the corresponding units are controlled while maintaining the consistency of control among the unit control means. 2. Among the plurality of units, each unit related to the paper transport system has at least one transport sensor on the transport path of the unit, and the unit control means in the unit is the transport sensor. 2. The image forming apparatus according to claim 1, wherein the conveyance control is performed based on the operation timing of. 3. Among the plurality of units, each unit related to image formation has a control timer for performing sequence control, and the unit control means in the unit includes:
The image forming apparatus according to claim 1, wherein the sequence control is executed based on an output value of the control timer. 4. The image forming apparatus according to claim 3, wherein the control timers of the respective units related to the image formation start measurement simultaneously by a common signal. 5. The common signal is a signal that is a common operation for each repeat copy and that indicates the operation start timing of the unit that operates first among the units associated with the image formation. The image forming apparatus according to claim 4. 6. The common signal is transmitted by a unit in charge of operation display among the plurality of units, and the unit in charge of operation display receives the common signal at the time of receiving a print key input. And transmitting the common signal to each unit associated with the image formation, and each unit associated with the image formation receives the common signal. The image forming apparatus according to claim 5, wherein each of the control timers is started according to the above. 7. A common transport path unit through which a sheet fed from each unit of the sheet feeding system passes, and
A transport unit control unit having a transport sensor disposed on the common transport path unit, wherein the transport unit control unit detects a sheet by the transport sensor;
The detection signal is transmitted to the unit control means of each unit related to the image formation, and the unit control means of each unit related to the image formation is based on the signal received earlier from the common signal and the detection signal. 7. The image forming apparatus according to claim 6, wherein each of the control timers starts its own control timer. 8. The unit related to the operation system among the plurality of units has operation key means and display means, and the unit control means of the unit related to the operation system is input information of the operation key means. 2. The copying mode and the copying start are set based on the status information input from each unit, and are displayed on the display means, and the copying mode and the copying start are output to each related unit. The image forming apparatus described.