JPH04199159A - Image forming device - Google Patents

Abstract

PURPOSE:To reduce the connection between a device main body and an external device and to decrease the overhead of the processing of software by reading the change of the state of the external device which is transmitted through a common bus and releasing the change of the state. CONSTITUTION:When a signal from the external device is fetched in a communication control circuit 112 through the SI terminal of the device main body and a reception control circuit 112g detects the start bit of the data '0', the data is serially fetched in a shift register 112f in synchronism with a transfer clock 112h from the circuit 112g. When a stop bit '1' is detected, the data fetched in the register 112f is transferred to a register 112j according to a control signal from the circuit 112g. When the reception of the data is finished, a transmission finish signal EOR is outputted from the circuit 112g to a CPU. When the state of the external device is changed, '1' '0' is outputted to the main body, and '0' is restored to '1' by receiving a command from the main body.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention is directed to performing an image forming operation on paper fed from, for example, a large-capacity feeder or a paper reversing feeder,
The present invention relates to an image forming apparatus such as a laser printer system or a copying machine system in which sheets on which images are formed are sorted and stacked using a sorter.

(Prior Art) In recent years, image forming apparatuses such as laser printers and copiers have been equipped with external feeding devices such as large-capacity feeders and paper reversing feeders, or external stacking devices (external stacking devices) such as sorters. ) systems have been developed in which multiple external devices are added.

In this type of system, it is necessary to connect multiple external devices to the image forming apparatus main body, so a dedicated signal line is provided for each device to send and receive data, and external devices and the image forming apparatus main body are connected. Connecting signal lines are commonly used to form an address/data bus, which is selected by software means to send and receive data to and from a corresponding external device.

However, in the former case, where each device has a dedicated signal line to send and receive data, the image forming device itself has hardware such as electrical circuits and connectors to connect the signal line with external devices. It is necessary to prepare software for each device, which increases costs. In addition, it is necessary to confirm each time which external device should be connected to which connector, making handling inconvenient.

In the latter case, that is, when the signal lines are shared to form an address/data bus, the image forming apparatus main body periodically connects the external devices in order to detect the status of all external devices. Communication must be performed while switching. Therefore, if the overhead of software processing becomes too large, resulting in poor efficiency, and if speeding up is required, the main body of the image forming apparatus itself may become uncontrollable.

Therefore, a configuration has been used in which a plurality of microcontrollers are provided in the main body of the image forming apparatus, and at least one microcontroller is used to control communication with an external device.

However, even with this method, the number of electrical circuits increases, which increases costs.Furthermore, it becomes necessary to control communication between microcomputers, which increases the size of the software, resulting in poor development efficiency. .

(Problem to be Solved by the Invention) As mentioned above, in the past, there was a large amount of hardware for connecting the image forming apparatus main body and external devices, and the overhead of software processing was too large, resulting in inefficiency. There were drawbacks.

SUMMARY OF THE INVENTION Accordingly, the present invention provides an efficient way to connect an image forming apparatus main body and a plurality of external devices with a minimum amount of hardware, and to reduce the overhead of software processing in communication between the image forming apparatus main body and external devices. The purpose is to provide an image forming apparatus with good quality.

[Configuration of the Invention (Means for Solving the Problems) In order to achieve the above-mentioned object, the image forming apparatus of the present invention includes a method for printing an image on an image forming medium fed from an external feeding device. and the image forming medium on which the image is formed is sorted and stacked in an external stacking device, wherein data is transmitted and received between the external feeding device and the external stacking device and the image forming device main body. a state change signal means that is timely sent from the external feeding device or the external accumulation device to inform the main body of the image forming apparatus of a change in state; and the data signal means and the state change signal means. A common bus means constitutes a common bus, and a control means reads a change in the state of the external feeding device or the external integration device sent via the common bus means and cancels the change in state. ing.

The image forming apparatus of the present invention also includes an image forming apparatus main body that performs an image forming operation on an image forming medium according to image information, and an image forming apparatus that is connected to the image forming apparatus main body and that is connected to the image forming apparatus main body from the outside. a plurality of external devices, such as an external feeding device that feeds the image forming medium to the image forming apparatus, an external stacking device that sorts and accumulates the image forming medium discharged from the image forming apparatus main body, and each of the external devices; and a data signal means for transmitting and receiving data between the image forming apparatus main body and the image forming apparatus main body, a state change signal means sent from each of the external devices in a timely manner to inform the image forming apparatus main body of a change in state, The data signal means and the state change signal means constitute a common bus, one of the common buses connects the image forming apparatus main body and one of the external devices, and the other common bus connects the external devices with each other. It is comprised of a common bus means for connection, and a control means for reading changes in the state of each of the external devices sent via the common bus means and for canceling the change in state.

(Function) The present invention allows data communication between the image forming apparatus main body and the external device, notification of a change in the state of the external device to the image forming apparatus main body, and cancellation thereof to be performed in one go by the above-described means.
Since it can be executed using a common lotus, the configuration and control can be simplified.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 13 shows an example of a laser printer system as an image forming apparatus of the present invention.

That is, this laser printer system includes a laser printer as an image forming apparatus main body, a large capacity feeder 2 as an external feeding device (external device), and a paper reversing feeder 3.
, and a sorter 4 as an external accumulation device (external device).

The laser printer 1 has a configuration as shown in FIG. 14, for example.

That is, numeral 5 in the figure is a printer body of the laser printer 1, and the rear part of the top surface of this printer body 5 is raised one step higher, and a four part 6 serving as a paper ejection part is formed in the center of the top surface. A paper output tray 8 movably supported by a jogger (not shown) is installed in the recess 6, and an operation panel is installed on the right side of the recess 6, and three IC card slots are installed on the left side. Ports (none of which are shown) are provided respectively.

A paper discharge tray 12 is provided on the front side of the printer main body 5, and a manual feed tray 13 is provided on the rear side. A paper detector 26 is provided at the bottom of the manual tray 13, and the paper (image forming medium) P inserted into the manual tray 13 is detected.

Further, a drum-shaped photoreceptor 15 as an image carrier is provided approximately at the center of the printer main body 5, and around this photoreceptor 15, a charging device 16, a laser optical system 17, a developing device]8 , a transfer device 19, a peeling device 20, a cleaning device 21, and a static eliminator 22 are arranged in this order.

Furthermore, a paper conveyance path 24 is formed inside the printer body 5 and extends forward through an image transfer section 23 formed between the photoreceptor 15 and the transfer device 19. The paper 21 is automatically fed from the paper feed cassette 25 stored in the paper feed roller 28 and the transfer roller 29b, etc. from the manual feed tray 13 or the above-mentioned large-capacity feeder 2 or paper reversing feeder 3 to the transfer roller 29a.
The fed paper P is guided to the image transfer section 23 via a paper feeder, etc.

Further, an aligning roller pair 30 is arranged on the upstream side of the image transfer section 23 of the paper conveyance path 24, and a fixing device 31, a paper ejection selector 32, and a paper ejection roller pair 33 are arranged on the downstream side.
are arranged respectively.

A branch conveyance path 35 is formed at the end of the paper conveyance path 24, and is provided with a pair of paper discharge rollers 34 in order to guide the sheets P sorted by the paper discharge selector 32 to the recess 6 serving as a paper discharge section. has been done.

Further, 47.49 in the figure is a printer circuit that controls the operation of the printer main body 5, and 48 is a printer circuit 47.4.
This is a printer control circuit that controls the operation of 9.

For example, a first
As shown in FIG. 5, a connector 1a for connecting to a host device (not shown) such as a computer or a word processor is provided, and a laser printer 1 is also provided.
A connector 1b is provided for sequentially connecting additional function devices (external devices) such as a large-capacity feeder 2, a sheet reversing feeder 3, and a sorter 4.

That is, in this invention, as shown in FIG. 13, for example, the large capacity feeder 2 is connected to the signal cable (common bus means) 9 to the connector 1b of the laser printer 1
It is connected via. The large-capacity feeder 2 and the paper reversing feeder 3, and the paper reversing feeder 3 and the sorter 4 are connected by signal cables (common bus means) 10 and 11, respectively.

During the image forming operation, the photoreceptor 15 is rotated and uniformly charged by the charging device 16. Then, the laser optical system 17 performs exposure corresponding to the image information, so that the photoreceptor 1
An electrostatic latent image is formed on 5. Next, this photoreceptor 15
The upper electrostatic latent image is developed by the developing device 18 and sent to the image transfer section 23 side as a developer image.

Meanwhile, in synchronization with this developer image forming operation, the paper 21 taken out from the paper feed cassette 25, the paper P1 manually fed from the manual feed tray 13, or the large capacity feeder 2
Or the paper P fed from the paper reversing feeder 3
is sent to the image transfer section 23 via the aligning roller pair 30. Then, in the image transfer section 23, the developer image formed on the photoreceptor 15 is transferred onto the paper P by the action of the transfer device 19. Thereafter, the paper P is peeled off from the photoreceptor 15 by the peeling device 20 and sent to the fixing device 31 via the paper transport path 24. Then, the paper P on which the developer image has been melted and fixed is guided to the sorter 4 by, for example, the paper discharge selector 32.

That is, the paper P(
Or paper P that is manually fed from the manual feed tray 13.
), for example, as shown in FIG. 16, the paper P is conveyed as indicated by the arrow in the figure. After being guided to the sorter 4 via the sheet reversing feeder 3, the sheets are sorted (divided and accumulated) as shown by solid lines or broken lines.

Further, the paper P fed from the large-capacity feeder 2 is transported in the direction of the arrow shown in the figure, as shown in FIG. 17, for example. Then, after being guided to the sorter 4 via the sheet reversing feeder 3, the sheets are sorted as shown by solid lines or broken lines.

Furthermore, the paper P fed from the paper reversing feeder 3
1, that is, as shown in FIG.
Paper P manually fed from 3 or paper P fed from large capacity feeder 2) is conveyed in the direction of arrow ■ along the paper conveyance path of paper reversing feeder 3, and then again in the direction of arrow ■ shown in the figure. After images are formed on both sides or only the back side of the paper P being conveyed, the paper P is led to the sorter 4 and sorted as shown by solid lines or broken lines.

Next, the configuration of the interface circuit (optional interface) will be described when the laser printer 1 is used as the main device and the large-capacity feeder 2, paper reversing feeder 3, and sorter 4 are each used as external devices.

FIG. 19 schematically shows the interface connection between the main device 1 and the external device 2.3.4.

That is, in the main device 1 and the external device 2.3.4, each communication circuit section described later is connected to an interface signal cable (corresponding to the signal cable 9.10.11 described above).
100.

FIG. 1 shows the configuration of the above communication circuit section.

In this figure, 110 is a communication circuit section of the main device 1, including a CPU 11 that controls the entire system, and a communication control circuit 1.
12, an internal data bus 113, and the connector 1b.

On the other hand, 120 is, for example, a communication circuit section of the external device 2, which includes a CPU 121, a communication control circuit 122, an internal data bus 123, and a first . It is composed of second connectors 124, 125, etc.

Although not shown, the communication circuit section of the external device 3.4 also has the same configuration as the communication circuit section 120 of the external device 2 described above.

The communication circuit section 110 of the main device 1 and the communication circuit section 120 of the external device 2 are connected to the interface signal cable 100.
Connector 1b of communication circuit section 110 and first connector 124 of communication circuit section 120 are connected via. The communication circuit section 120 of this external device 2 also includes a second
The communication circuit section of the external device 3 is connected to the communication circuit section of the external device 3 via the interface signal cable 100 extending from the connector 125, and the communication circuit section of the external device 4 is connected to the communication circuit section of the external device 3 via the interface signal cable 100. has been done.

The above interface signal cable 100 is TXD, R
XD, INT (state change signal).

It is composed of four GND signal lines.

TXD is a signal for transmitting a command from the main device 1 to the external devices 2, 3.4. For example, as shown in FIG. 2, a start bit of "0" and the following bit data DO~ D7 and a stop bit of "1" are transmitted serially.

Bit data DO to D7 are defined as data indicating the contents of various commands, as shown in FIG. 3, for example. That is, among the bi-soto data DO to D7, D
7. D6 is an optional ID bit for specifying an external device (option), and D5 to DO are command bits indicating the contents of the command.

An example of the command sent in this embodiment is shown in the fourth example.
Shown in the figure.

RXD is a signal for transmitting status from the external devices 2, 3.4 to the main device 1, and has the same configuration as the TXD shown in FIG.

The bit data D7 to DO of RXD are status bits for indicating the content of the status, as shown in FIG. 5, for example. That is, in the case of the large-capacity feeder basic status, each bit D7 to Do is given a meaning, as shown in FIG. 6, for example. Further, in the case of the paper reversing feeder basic status, each bit D7 to DO is given a meaning, as shown in FIG. 7, for example. In addition, in the case of the large-capacity stacker basic status, each bit D7 to
The meaning of Do is given. Furthermore, in the case of the sorter basic status, each bit D7 to DO is given a meaning, as shown in FIG. 9, for example.

INT is an interrupt signal from the external device 2, 3.4 to the main device 1, and is sent when a change occurs in the state of the external device 2, 3.4 or when the power of the external device 2.3.4 is turned on. "1" when the above status is confirmed from
The value changes from 0 to 0, and returns to 1 when a command from main device 1 is received.

GND is a signal provided to connect the ground of the main device 1 and each external device 2, 3.4.

Among these signals, the TXD signal line is connected to the SO terminal of the communication control circuit 112 of the communication circuit section 110 on the main device 1 side, and to the SL terminal of the communication control circuit 122 of the communication circuit section 120 on the external device 2 side. It is connected.

Further, the RXD signal line is connected to the Sl terminal of the communication control circuit 112 on the main device 1 side, and connected to the transistor 126 of the communication control circuit 122 on the external device 2 side, so that it is output from the oven collector. .

Further, the INT signal line is connected to the CPU 111 of the communication circuit section 110 on the main device 1 side, and is connected to the transistor 127 of the CPU 121 of the communication circuit section 120 on the external device 2 side.
is connected to the oven collector for output.

FIG. 10 shows the configuration of the communication control circuit 112 described above.

When transmitting data, the CPU 111 first sends the data to the register 1 via the internal data bus 113.
12a. Then, the start bit and stop bit are added as described above by the control signal 112c from the transmission control circuit 112b. After this transmission data is transferred to the shift register 112d, this data is serially output from the SO terminal in synchronization with the transfer lock 112e from the transmission control circuit 112b. Further, when the data transmission is completed, the transmission control circuit 112b sends a pulsed transmission end signal EOT to C.
Output to PUI 11.

In this way, the TX from the communication circuit section 110 described above is
The transmission of D is controlled.

On the other hand, the received data is transferred from the Sl terminal to the communication control circuit 112.
and input into the shift register 112f and the reception control circuit 112g, respectively. When the start bit of data is detected in the reception control circuit 112g, the transfer lock 11 is activated from the reception control circuit 112g.
Data is serially taken into the shift register 112f in synchronization with 2h. Further, when a stop bit is detected, the control signal 11 from the reception control circuit 112g is
21 transfers the data taken into the shift register 112f to the register 112j. In this way, when data reception is completed, a pulsed transmission end signal EOR is sent from the reception control circuit 112g to the CPU 11.
Output for.

Furthermore, the data stored in the register 112j is sent to the CPUI 11 via the internal bus 113.

In this way, the RX from the communication circuit section 110 described above
The reception of D is controlled.

Note that 112 in the figure is an oscillation circuit that generates a clock 112g for synchronizing communication.

In addition, although the communication control circuit 112 on the main device 1 side has been explained here as an example, the communication control circuit 122 on the external device 2 side has a similar configuration, and TXD reception and RXD transmission are controlled. It has become so.

As described above, in this embodiment, the connector 1b of the main device 1 and the first connector 124 of the external device 2 are connected by the signal cable 100, and further connected to the second connector 125 of the external device 2. Signal cable 1
00 is connected to another external device, for example, external device 3. Therefore, the signal cable 100 described above can constitute a common bus between the main body device 1 and each external device 2.3.4.

Next, the transmission of the basic status request command and basic status performed between the main device 1 and each external device 2, 3.4 in the above configuration will be explained.

FIG. 11 shows that, for example, when a state change occurs in the external device 2, or when the status is determined after the power is turned on, the INTO is changed from "1" to "0" by the external device 2.
This example shows the case where is output.

In this case, INT is equal to INTO, and by detecting INT "1" → rOJ in the main device 1, the basic status request command CMDO to the external device 2 is changed to T.
Output on XD. Then, when the command transfer is completed, the main unit 1 sends an EOT indicating the end of data transmission.
At the same time, the external devices 2, 3.4 generate EORO, EORI, and EOR2, respectively, indicating the end of data reception.

CMDO makes only the external device 2 responsive by analyzing the option ID bit, INTO is changed to "1", and basic status STSO is output on RXD.

Furthermore, when the status transfer is completed, the external device 2
Then, EOTO indicating the end of data transmission is generated, and at the same time, the main body device 1 generates EOR indicating the end of data reception. At this time, if the above INT is "1",
The main device 1 determines that a change in the state of the external device 2 has occurred, and communication with all external devices 2, 3.4 is terminated.

Note that D7 of each basic status sent from the external device 2.3.4 is an interrupt cause bit (see Figures 6 to 9) that indicates that a change in its own status has occurred, and in this case, it is set to "1". is now set.

FIG. 12 shows that following the occurrence of a state change in the external device 2,
The example shows the transmission and reception of commands and status when a state change occurs in the external device 4 as well.

In other words, INTO “1” → rOJ is detected,
As described above, the basic status request command CMDO and basic status 5TSO are sent and received to and from the external device 2. In this case, INTO is changed to “1” or INTO is changed to “1” or
Since INT2, which indicates the occurrence of a state change in the external device 4, is "0" while TO is "0", INT is in the "O" state.

In this state, the main device 1 transmits the basic status request command CMD 1 to the external device 3 and receives the basic status STS 1. In this case, since no state change occurs in the external device 3, I
NT is in the "0" state. Also, basic status 5T
The interrupt factor bit D7 of SI is "0". Therefore, the main device 1 does not need to process the status of the external device 3, and can immediately perform the next process.

Further, in the main device 1, a basic status request command CMD2 to the external device 4 is transmitted, and a basic status 5TS2 is received. In this case, since INT2 indicating the occurrence of a state change in the external device 4 becomes "1", INT returns to the state of "]".

In this way, when the INT changes from "0" to "1", the main unit 1 sends a status request command to the TXD, and in response, reads the status on the RXD when the INT changes from "0" to "1". By repeating this until it changes to ``, you can know the changed basic status.

As described above, data communication between the main unit and the external device, notification of a change in the state of the external device to the main unit, and release thereof can be performed using one common bus.

In other words, when a state change occurs in a signal cable that transmits and receives data between the image forming apparatus main body and multiple external devices, and in each external device connected to the image forming apparatus main body by means of a logical sum, The image forming apparatus main body transmits and receives data to and from the external device based on the interrupt signal when a state change occurs in the external device, and the above-mentioned interrupt signal is sent when the contents of the state change are read. I am trying to cancel the signal. This makes it possible to know the occurrence and contents of a change in the state of the external device in a timely manner.

Therefore, multiple external devices can be connected to the image forming apparatus main body with a minimum amount of hardware, reducing costs and reducing software overhead due to communication with external devices. This makes it possible to simplify control.

Another advantage is that only one connector is required for connecting an external device to the main body of the image forming apparatus.

It should be noted that the present invention is not limited to the embodiments described above, and it goes without saying that various modifications can be made without departing from the gist of the invention.

[Effects of the Invention] As detailed above, according to the present invention, the image forming apparatus main body and a plurality of external devices can be connected with a minimum amount of hardware, and the image forming apparatus main body and the external devices can be connected. It is possible to provide an efficient image forming apparatus that can reduce the overhead of software processing in communication.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention. FIG. 1 is a block diagram showing the configuration of a communication circuit section, FIG. 2 is a diagram showing an example of the configuration of a TXD (or RXD), and FIG. Figure 4 shows an example of the configuration of bit data, Figure 4 shows a list of command contents, Figure 5 shows an example of the configuration of bit data (status bits) in RXD, Figure 6 shows a large capacity Figure 7 shows an example of the feeder basic status.
8 is a diagram showing an example of the basic status of a large-capacity stacker, FIG. 9 is a diagram showing an example of the basic status of a sorter, FIG. 10 is a block diagram showing an example of the configuration of a communication control circuit, and FIG. 12 and 12 are timing charts shown to explain basic status request commands and transmission of basic status performed between the main unit and each external device, respectively, and FIG. 13 is an image formation example using a laser printer system. A configuration diagram of the apparatus, FIG. 14 is a side sectional view showing the configuration of the laser printer, FIG. 15 is a diagram showing the configuration of the back side of the laser printer, and FIGS. 16 to 18 are paper sheets in each image forming mode. FIG. 19 is a diagram showing an outline of the interface connection between the main body device and a plurality of external devices. DESCRIPTION OF SYMBOLS 1...Laser printer (main device), 1b...Connector, 2...Large capacity feeder, 3...Paper reversing feeder, 4...Sorter, 9, 10.11...Signal cable, 15... Photoreceptor, 16... Charging device, 17.
... Laser optical system, 18... Developing device, 19... Transfer device, 31... Fixing device, 100... Interface signal cable, 110... Communication circuit section (main device side), 111 ...CPU, 112--Communication control circuit, 1.12 a. 112j...Register, 1]2b...Transmission control circuit, 112d, 112f...Shift register, 112g
...Reception control circuit, 112k...Oscillation circuit, 113
... Internal data bus, 120 ... Communication circuit section (external device side), 121 ... CPU, 122 ... Communication control circuit, 123 ... Internal data bus, 124.125.
... 1st ° 2nd connector, P... paper (image formation medium). /11゜1st! ! I +3"44 Large Capacity Feeta Basic Status No. 6 Diagram Piece 1 Distribution◆Yu Feeter Basic Status No. 7 No. 181!

Claims (2)

[Claims] (1) In an image forming apparatus configured to form an image on an image forming medium fed from an external feeding device, and to sort and stack the image forming medium on which the image is formed in an external stacking device, the above-mentioned data signal means for transmitting and receiving data between the external feeding device and the external accumulating device and the image forming apparatus main body; a state change signal means for notifying a change in state; a common bus means in which the data signal means and the state change signal means constitute a common bus; and the external feeding device or external integrated device sent via the common bus means. 1. An image forming apparatus comprising: a control means for reading a change in state of the image forming apparatus and for canceling the change in state. (2) an image forming apparatus main body that performs an image forming operation on an image forming medium according to image information; and an image forming apparatus that is connected to the image forming apparatus main body and feeds the image forming medium from the outside to the image forming apparatus main body. between each of the external devices and the image forming apparatus main body; a data signal means for transmitting and receiving data; a state change signal means timely sent from each of the external devices to inform the main body of the image forming apparatus of a change in state; and the data signal means and the state change signal means. configuring a common bus, one of the common buses connects the main body of the image forming apparatus and one of the external devices, and the other common bus connects the external devices with each other; An image forming apparatus comprising: a control means for reading a change in state of each of the external devices sent through the means, and for canceling the change in state.