JP3056752B2 - Image forming system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to various types of printer systems such as laser printers, LED printers, liquid crystal shutter printers, and ink jet printers, or images such as high-function copiers and high-function faxes. Related to the forming system.

[Conventional technology]

2. Description of the Related Art In recent years, image forming apparatuses such as laser printers have tended to be systematized so as to meet various demands, and receive character information or image information from a host system such as a word processor, an office computer, or a personal computer to obtain an image. An image processing apparatus for generating information, an image forming apparatus for receiving image information from the image processing apparatus and forming an image on a recording medium, and each of which is detachably attachable to the image forming apparatus and feeds and discharges the recording medium. Image forming systems are being constructed by connecting various types of additional devices to be sent or conveyed via respective interfaces.

In some cases, the host system has a function corresponding to the image processing apparatus. In such a case, the image forming apparatus directly receives image information from the host system and forms an image on a recording medium.

[Problems to be solved by the invention]

However, in such an image forming system, conventionally, when a host system or an image processing apparatus inquires of an image forming apparatus (including an additional apparatus) about information such as its state, a plurality of pieces of information are effectively present. Also,
Only the information with the highest priority (top position) was returned.

Alternatively, as means for simultaneously returning a code corresponding to a plurality of information, each bit of a response of a plurality of bits (for example, 8 bits) is assigned to various types of information (errors, etc.), and a flag is generated for the generated bit. It is conceivable that a reply is made with a response, but only limited information can be notified by the number of bits of the response.

The present invention has been made in view of such a problem, and a host system or an image processing apparatus puts a plurality of pieces of information (such as status information and numerical information) generated on an image forming apparatus side at the top level. Not only the information that was positioned,
The purpose is to be able to know all the information at one time if necessary.

[Means for solving the problem]

In order to achieve the above object, the present invention provides an image processing apparatus which receives character information or image information from a host system to generate image image information, and receives an image image information from the image processing apparatus and forms an image on a recording medium. In an image forming system in which an image forming apparatus to be formed is connected via an interface, the image processing apparatus transmits a code corresponding to information positioned at the highest position among information effective for the image forming apparatus. Means for sending a command having a flag indicating whether to inquire or to inquire about a code corresponding to the information positioned next to the previously responded information, and the image forming apparatus sets the flag when the command is received. The code corresponding to the information positioned at the top of the valid information according to the And a means for returning a code corresponding to the information positioned to the image processing apparatus to the image processing apparatus.

Further, in an image forming system in which a host system and an image forming apparatus that receives image image information from the host system and forms an image on a recording medium are connected via an interface, the host system includes: A flag indicating whether to inquire the image forming apparatus of the code corresponding to the information positioned at the top of the valid information or to query the code corresponding to the information positioned next to the previously responded information; Means for transmitting a command, the image forming apparatus, when the command is received, next to the code corresponding to the information positioned at the top of the valid information according to the flag or the information responded last time There is provided means for returning a code corresponding to the positioned information to the host system.

(Operation)

In the image forming system according to the present invention having the above-described configuration, when the image processing apparatus or the host system transmits a command for inquiring valid information to the image forming apparatus, it is determined whether or not one of the flags is set. Thus, a code corresponding to the information positioned at the highest position on the image forming apparatus side or a code corresponding to the information positioned next to the previously responded information can be sequentially returned.

Therefore, the host system or the image processing apparatus only issues the same inquiry command a required number of times,
Since it is possible to know all of a plurality of states or numerical information generated on the image forming apparatus side, it is possible to provide a flexible response and to transmit accurate information to a host system or a display.

〔Example〕

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a block diagram showing a system configuration of a basic embodiment of the present invention.

The image forming system includes an image forming apparatus main body 4 that receives character code information or image image information from a host system 1 and forms an image on a recording medium, and includes five detachable image forming apparatus main bodies 4 respectively. Additional device 5A
To 5E.

That is, as the additional devices, a multi-stage paper feeding device 5A and a large-volume paper feeding device 5B, which are additional paper feeding devices, an inverted paper discharging device 5C and a large-volume paper discharging device 5D, which are additional paper discharging devices, and an additional recording medium transport device. The two-sided conveyance device 5E is connected to the image forming apparatus main body 4
Are mechanically connected to each other, and they are all connected by a common signal line (serial bus) SB.

The image forming apparatus main body 4 and each of the additional devices 5A to 5E are provided with serial communication sections 4a and 5a to 5e as communication means for performing serial communication via signal lines SB.

Further, a command issuing unit is provided in the image forming apparatus main body 4.
4b, the command issuing means 4b converts a command including an identification code for individually specifying each of the additional devices 5A to 5E and a command including a common identification code for specifying all of the additional devices as necessary. It is issued and transmitted to each of the additional devices 5A to 5E via the signal line SB by the serial communication unit 4a.

Therefore, the image forming apparatus main body 4 can usually specify and control each of the additional devices 5A to 5E individually, and if necessary, for example, a serious error occurs in the system, For example, if you want to stop all mechanical operations in the system, issue and send a command containing a common identification code that specifies all the additional devices, and simultaneously perform an emergency stop to each of the additional devices 5A to 5E. Information such as instructions can be transmitted and executed.

Here, a communication protocol between the image forming apparatus main body 4 and each of the additional devices 5A to 5E will be briefly described.

Communication from the image forming apparatus main body to the additional apparatus is performed by transmitting a command, and communication from the additional apparatus to the image forming apparatus main body is performed by transmitting a response.

As shown in FIG. 2, one command is composed of an 8-bit operator and an argument, and transmits the argument first and then the operator.
Top three bits b ₇ ~b ₅ of Agiyumento is always "111".

Then, the normal command, as shown in FIG. 2 (a), placed in an identification code adding device for specifying the upper three bits b ₇ ~b ₅ of the operator as the communication partner (ID), b ₄ ~b ₀ Is a code indicating the type of instruction.

Here, the identification code (ID) of each of the additional devices 5A to 5E in the embodiment of FIG. 1 is determined as follows, for example.

Multi-stage paper feeder 5A: 000 (IN # 1) Large-volume paper feeder 5B: 001 (IN # 2) Screen transport device 5E: 010 (DPX # 1) Reversed paper output device 5C: 100 (OUT # 1) Mass discharge Paper device 5D: 101 (OUT # 2) The upper two bits of the three-bit identification code indicate the type of additional device (type: paper feed, transport, discharge), and the lower one bit is the device number (#). 1 or # 2), which is clearly indicated in parentheses.

FIG. 2 (b) shows a configuration of a command (hereinafter, referred to as "global ID command") including a common identification code (hereinafter, referred to as "global ID address") for specifying all the additional devices.

The global ID command, and the upper three bits b ₇ ~b ₅ of the operator, a global ID address "110",
In b _{4 to} b ₀ , a code indicating the type of instruction, for example, in the case of an emergency stop instruction, “01111” is entered for b _{4 to} b ₀ .

When each of the additional devices 5A to 5E receives this global ID command in its respective serial communication unit, it recognizes that it has been specified and immediately executes the command without returning a response.

An example of using the global ID command is as follows.

(A) When performing system initialization (initialization operation and self-diagnosis).

(B) When the paper size is set in each additional device when an image forming operation is performed by selecting a paper feeding device that cannot detect the paper size by itself.

(C) When it is necessary to urgently transmit information to all the additional devices (for example, when transmitting an emergency stop command when a paper jam occurs).

Logical ID and Device ID FIG. 3 is a block diagram showing the basic configuration of an embodiment in which the expandability of the image forming system according to the present invention is further enhanced, and portions corresponding to those in FIG. Therefore, their description is omitted.

The image forming system includes an image forming apparatus main body 4 that receives character code information or image image information from a host system 1 and forms an image on a recording medium, and includes seven detachable image forming apparatus main bodies 4 respectively. Additional device 5A
The system is configured by ~ 5G.

That is, a multi-stage paper feeder 5F and a multi-stage paper discharge device 5G are added to the image forming system of FIG. 1 as additional devices, and the image forming apparatus main body 4 and each of the additional devices 5A to 5G share a common signal. Connected by line SB. It is possible to add more additional devices as indicated by the broken lines.

The image forming apparatus main body 4 according to this embodiment includes:
A maximum of two additional paper feeders, a maximum of two additional paper discharge devices, and a maximum of one additional double-sided conveyance device can be simultaneously controlled.

Here, being able to control at the same time means a state satisfying all of the following.

○ Direct communication enables processing of execution commands, inquiry commands, selection commands, etc.

○ Feeding, conveying, and discharging of recording media can be executed by commands.

○ It can be selected as the transport path of the recording medium

Therefore, the image forming apparatus main body 4 has six types of codes as control identification codes (hereinafter, referred to as “logical (logical) IDs”). This corresponds to the identification code (ID) of each additional device in the above-described embodiment.

That is, all additional devices (option units) are classified into three types of unit types, namely, a paper feeding device, a paper discharging device, and a transporting device.
ID is prepared.

Additional paper feeder (IN # 1): 000 Same (IN # 2): 001 Additional transporter (DPX / INP): 010 Same (DPX / OUT): 011 Additional paper ejector (OUT # 1): 100 Same ( OUT # 2): 101 This logical ID is a 3-bit code, of which the upper 2 bits are unit type codes for identifying IN, OUT, and DPX, and the lower 1 bit is a number of # 1 or # 2. (Additional conveyance device, that is, double-sided conveyance device: In the case of DPX, this is a code for identifying as an input unit (INP) or an output unit (OUT)).

The image forming apparatus main body 4 has a serial communication function of transmitting a command including the logical ID to the signal line SB, and all of the internal image processing unit, the image creating unit, and the external host system normally operate the logical ID. Using each additional device
Identify 5A-5G.

On the other hand, each of the additional devices 5A to 5G has a unique identification code (hereinafter referred to as “device (physical) ID”) and has a serial communication function of sending a response including the device ID to the signal line SB. .

In addition, each unit has its own unit type, that is, a paper feeding device (IN), a paper discharging device (OUT), and a double-sided conveying device (DP).
X) is stored as a two-bit code like the unit type code of the logical ID.

If the device ID is given by a 4-bit code for each unit type, 16 units can be identified for each unit type, for a total of 48 units.

In this embodiment, device IDs are assigned as follows.

Multi-level paper feeder 5A: (IN) 0000 Multi-level paper feeder 5F: (IN) 0001 Large-volume paper feeder 5B: (IN) 0010 Reverse paper output device 5C: (OUT) 0000 Multiple paper output device 5G: (OUT) 0001 Mass discharge device 5D: (OUT) 0010 Double-sided transport device 5E: (DPX) 0001 In addition, IN, OUT, DPX in parentheses is actually a 2-bit unit type code and is only for each additional device (option unit). The device ID is stored separately, and only the 4-bit code after that is the device ID.

Therefore, in the image forming apparatus main body 4, an additional device in the same unit type is designated (assigned) to each logical ID, and the device ID is stored in a table in the memory, for example, as shown in the following table. .

On the other hand, each of the additional devices 5A to 5G has its own unit type code (IN, DPX, OUT identification code) and a memory for storing the device ID, and a memory when the logical ID is assigned (specified). And a memory for storing a logical ID.

In this way, the six logical IDs and the device IDs of the additional devices respectively assigned thereto (however, DPX
・ The device ID of the same transport device for both sides is used for INP and DPX / OUT
The image forming apparatus main body 4 can specify and control the assigned additional device only by the logical ID.

In FIG. 3 and the above-described example, as a supplementary paper feeder, a logical ID (indicated by “Log” in FIG. 3), IN # 1 is a multiple paper feeder 5A, and IN # 2 is a large-volume paper feeder 5B. Inverted paper output device 5C, OUT # 2 to OUT # 1 of logical ID as additional paper output device
To the DPX (I)
NP and OUT) are assigned to the double-sided transfer device 5E.

In FIG. 3, the assigned additional device is indicated by a double-lined frame. Therefore, the image forming apparatus main body 4 can simultaneously control the five additional devices 5A to 5E.

However, since this assignment state can be changed as needed, it can be used even when other additional devices, that is, the multi-stage paper feeding device 5F and the multi-stage paper ejection device 5G or more additional devices are added. , You can make them available.

In addition, between the image processing apparatus and the image forming apparatus in the image forming apparatus main body 4, and between the image forming apparatus main body 4 and each additional device
The communication protocol for serial communication between ~ 5G provides two levels of commands.

One of them is a basic command. When the image forming system includes two or less additional paper feeding devices, two or less additional paper discharging devices, and one or less double-sided conveyance device, a logical command is issued. The basic command, which is a command for handling only the additional device registered in the ID, can include all system functions.

Thus, an image forming system in which all system functions can be controlled by a basic command is referred to as a basic system. In this system, the code number of the device ID may be the same as the code number of the logical ID. The embodiment shown in FIG. 1 corresponds to this basic system.

The other is an enhancement command (extended command). If the image forming system has three or more additional paper feeders, three or more additional paper discharge devices, or two or more double-sided conveyance devices, the three commands are used. The additional paper feeding device or additional paper discharging device and the second and subsequent double-sided conveying devices assign the device ID to the same unit-type logical ID using the enhance command, and thereby, This makes it possible to control paper feeding, paper discharging, double-sided conveyance, and the like.

By the way, according to the image control system, each additional device (5A to 5E in FIG. 3) assigned from the image processing device in the image forming device main body 4 to the image forming device or via the image forming device. ), A command for inquiring about the state is issued, and the image forming apparatus or a specific additional apparatus can sequentially return the plurality of states according to the priority order.

Such functions according to the present invention will be described in detail in the following description of specific embodiments.

Laser Printer System An embodiment in which the present invention is applied to a laser printer system will be described below.

FIG. 4 is a block diagram showing a schematic configuration of the laser printer system, and portions corresponding to FIGS. 1 and 3 are denoted by the same reference numerals.

This laser printer system has a host system 1
A printer main body 4 which is an image forming apparatus main body including a controller 2 and a print engine (hereinafter, simply referred to as an "engine") 3; and various additional devices (hereinafter, "option units") such as the above-described additional devices 5A to 5G. 5)
And a host interface (hereinafter abbreviated as "host I / F"), a laser printer video interface (hereinafter abbreviated as "LPVI"), and an engine option interface (hereinafter referred to as "EOI"). / F ").

The host system 1 is an information processing device such as a word processor, an office computer, or a personal computer for transmitting character information or image information.

The controller 2 is an image processing apparatus that receives character information and image information from the host system 1 and generates image image information (video data) for each page of a print sheet.

The engine 3 is an image forming apparatus that prints image information generated by the controller 2 on paper.

The host I / F is an interface for connecting between the host system 1 and the controller 2, and RS232C, Centronics I / F and the like are well known.

The LPV 1 is a standard interface that connects the controller 2 and the engine 3 that constitute the printer body 4, and unifies the hardware of the video interface that has been individually determined for each engine (for each model) in the past. It is not affected by the function.

The EOI / F connects the engine 3 and the various option units 5 by the above-described common signal line (serial bus), and transmits a command including the above-described logical ID from the engine 3 so that the engine 3 can use the ID. This is a standard interface for serial communication by returning a response from the specified option unit.

 FIG. 5 shows a hardware configuration of the controller 2.

The controller 2 includes a CPU 20 and a program RO as shown in the figure.
M21, RAM22, font ROM23, nonvolatile RAM24, operation panel 2
5, a scaling unit 26, an option interface 27, a video control unit 28, an engine interface 29, and the above-mentioned host interface 4 and the controller side of the LPVI, all of which are connected by a CPU bus.

The CPU 20 is a central processing unit for controlling the whole of the controller 2, and uses a general-purpose 16-bit or 32-bit microcomputer.

The program ROM 21 stores microcode (program) for controlling the CPU 20.

The RAM 22 is a large-capacity random access memory, and is mainly used for the following purposes.

(A) System memory (b) Input buffer (c) Page buffer (d) Font file (e) Macro file (f) Image file (g) Print control file (h) Video buffer FIG. 6 shows the flow of data processing. And the relationship between each buffer and file in the RAM 22.

Information sent from the host system 1 is stored in the input buffer 22b via the host interface 4.

The data stored in this input buffer 22b is
The data is extracted by the data processing unit 201 and registered in one of the page buffer 22c or the font file 22d, the macro file 22e, the image file 22f, and the print control file 22g according to the type of data.

That is, the print sequence control data (designation of the paper transport path, the number of prints, etc.) is stored in the print control file 22g, the page layout information (the relation between the print data and the print position) is stored in the page buffer 22c, and the image information is stored in the image file 22f. The download font is registered in the font file 22d, and the overlay information and the like are registered in the macro file 22e.

The image information processing unit 202 includes an image file 22f and a font file 22d in accordance with the contents of the page buffer 22c.
Then, the contents of the font ROM 23 are expanded into the video buffer 22h through the scaling unit 26.

When the development of the print data for one page is completed in the video buffer 22h, the print control unit 203 activates the engine 3 via LPVI according to the contents of the print control file 22g, and when the engine 3 reaches the image recording timing, the video buffer 22h. LPVI with expanded video data
To the engine 3 via

The engine 3 prints the video data sent via the LPVI on a sheet.

Returning to FIG. 5, the font ROM 23 stores font data for converting character information transmitted from the host system 1 via the host interface 4 into image information.

The nonvolatile RAM 24 is a memory for storing information for controlling the operation state of the printer after the power is turned on,
The following items are mainly stored.

(A) printing direction (b) font (font) (c) character size (d) line spacing (e) paper feed port (f) paper discharge port (g) host interface Updated from panel 25.

FIG. 7 shows an example of the appearance of the operation panel 25. An operation of updating the storage content of the nonvolatile RAM 24 by using the operation panel 25 is called a mode set.

The operation panel 25 has an LCD display 250 for displaying the status of the printer and the contents of the mode set in characters, a power LED 251 that lights up when the power is turned on, an online LED 252 that indicates the online status of the printer, and lights up when the printer is abnormal. Or blinking attention LED 253, data LED 254 indicating that there is print data in the printer, online switch 255 for switching the printer online / offline, and printing data in the printer when the data LED 254 is lit. Form Fee
d) A switch 256, a test switch 257 for activating a self-diagnosis test function of the printer and the like, a reset switch 258 for resetting the printer, and switches 25A, 25B, 25C and 25D for operating the mode set.

The contents of the mode set are arranged in a hierarchical manner as shown in FIG.

Then, in the online state, the mode switch of the upward arrow
By pressing 25A, the mode is set, and the "print direction" of the first level is selected. To select another item on the first level, the left or right arrow switch 25B or 25C is operated.

Each time you press the right arrow switch 25C, the set items are “Font font”, “Character size”, “Line spacing”, “Paper slot”, “Paper slot”
It changes to "host interface".

On the other hand, each time the left arrow switch 25B is pressed, the set item changes from “host interface” to “paper discharge port” “paper feed port” in the reverse direction.

If the item to be set is "typeface", "typeface" is selected by the right arrow switch 25C, and then the down arrow arrow switch 25D is pressed to shift the hierarchy to the second hierarchy.

Then, there are three typefaces in the second hierarchy, namely, Courier, Elite, and Gothisk.
c) One of them is selected by the left and right arrow switches 25B or 25C.

For example, when selecting "elite" and setting it, pressing the down arrow enter switch 25D registers "elite" in the nonvolatile RAM 24. That is, by pressing the ENTER switch 25D at the bottom layer, the nonvolatile RAM
24 registrations are updated.

In the other set items of the first layer, "Printing direction" is vertical and horizontal, "Character size" is 8 points, 10 points, and 12 points, and "Line spacing" is 3LPI (Line / Inch), 6LPI, 8LPI To
The “paper feed slot” refers to the upper paper feed cassette, the lower paper feed cassette, and the large-volume paper feed unit. The “paper discharge port” refers to the upper paper discharge tray, side discharge tray, and large-volume paper discharge unit. The “host interface” Centronics and RS-232C can each be selected in the second layer.

Further, when RS-232C is selected as the "host interface", the type of parity check and the baud rate (communication speed) can be selected and set in the third hierarchy.

Returning to FIG. 5, the scaling unit 26 is a scaling unit for scaling the image information to an optimum size in accordance with the resolution of the engine 3.

The host interface 4 is an interface for connecting the host system 1 and the controller 2, and selects one of two, a Centronics-compliant parallel and an RS-232C, by operating the operation panel 25 described above.

The option interface 27 is an interface for supplying a font or a program from the outside in order to extend the function. In this example, two IC cards 6 can be handled.

The IC card 6 is a commercially available one, and there are a card storing a font card, a program card, or both depending on the type of data stored, but they are physically the same.

As shown in FIG. 9, the file format of the IC card 6 includes a file size, CRC check data, a file type, a resolution, and font data or a program.

The type of data is determined based on the file type. That is, if the file type is “1”, the file is font, and if the file type is “0”, the file is program.

Returning to FIG. 5, the video control unit 28 converts the video data stored in the video buffer 22h of FIG. 6 with the bus width (16 bits or 32 bits) of the CPU 20 into serial data or 8-bit parallel data. And sends it to Engine 3 via LPVI.

The engine interface 29 has a serial communication (transmission / reception) function of detecting the state of the engine by a bidirectional serial signal via the LPVI and transmitting a command to control the engine.

Here, the LPVI signal is shown in FIG. The signal includes an image signal system, a control signal system, and a power supply.

The image signal system is / WCLK, / WDATA, / LSYNC, / LGATE, / FG
There are five types of ATE signals.

The control signal system consists of four signals: / PETXD, / PERXD, / PECTS, / PEDTR
The power supply is of two types: + 5V and GND.

Here, “/” added to the front of each signal name indicates negative logic (low active), and is shown with an overline in FIG.

(A) / WCLK: Clock for synchronizing image data from print engine. The image is printed by transmitting the image data (/ WDATA) in synchronization with the fall of this signal. Low level is black.

(B) / WDATA: image data sent from the video control unit 28 in FIG.

(C) / LSYNC: Line synchronization signal indicating the start of each scan line.

 Synchronizes with the falling edge of the / WCLK signal.

(D) / LGATE: a signal indicating the effective image area of each scan line.

 Synchronizes with the falling edge of the / WCLK signal.

(E) / FGATE: A signal indicating the effective image area in the paper feed direction. Synchronizes with the fall of the / LSYNC signal.

(F) / PETXD: status signal for notifying the controller of the engine status from the engine.

(G) / PERXD: Command line from the controller to the engine.

(H) Indicates the ready of the / PECTS: / PETXD signal. When this signal is at a low level, it is possible to send a status from the engine to the controller.

(I) Indicates the ready of the / PEDTR: / PERXD signal. When this signal is at a low level, a command can be sent from the controller to the engine.

(J) + 5V: + 5V power supplied from the engine.

(K) GND: Ground (Earth) FIG. 11 shows the relationship between the print area and the image signal.

Reference numeral 7 denotes an effective printing area, 8 denotes an image area printed by the / WDATA signals 8a and 8b, and 9 denotes an image area printed by the / WDATA signals 9a and 9b.

Next, the structure of the engine will be described with reference to FIG. 12 and FIG.

FIG. 12 is a schematic view of an engine main body constituting a mechanism of the engine 3 of the above-described laser printer system, and mechanisms of various option units connected thereto.

Reference numeral 10 denotes an engine body, which includes a photosensitive drum 101, a charging charger 102, a light (laser) writing unit 103, a developing unit 104, a transfer separation charger 105, a cleaning unit 106, a fixing unit 107, and a plurality of registration rollers 108. And a drive motor and a drive mechanism for the rollers.

Reference numerals 11 and 12 denote paper cassettes (trays) which are directly mounted on the engine body 10 and can normally store 100 to 200 sheets of paper. It is also possible to insert a multi-stage paper feeding unit corresponding to the above-described multi-stage paper feeding device 5A, 5F having a multi-stage paper feeding cassette (tray) into the two paper feeding cassette insertion openings of the engine body 10. it can.

Reference numeral 13 denotes a reversing device for switching a paper discharge path, which corresponds to the above-described reverse paper discharge device 5C, and has a paper discharge path of its own upper paper discharge tray 14,
It can be switched to any of a mail box (multi-stage paper discharging device) 15, a double-sided paper unit 16, and a large-volume paper discharging unit 18.

Further, other than the upper discharge tray 14, a sheet which is turned upside down can be supplied to each unit. Of course, unreacted paper can also be supplied. Therefore, face-up discharge and face-down discharge can be arbitrarily selected by using this function.

15 is a mail box having a large number of output trays 15a,
It corresponds to the above-described multi-stage paper ejection device 5G, and can select an arbitrary paper ejection tray according to an instruction from the controller 2.

Reference numeral 16 denotes a double-sided unit serving as a re-feeding unit for double-sided printing, which corresponds to the above-described double-sided conveying device 5E, and the paper printed on one side by the engine body 10 is supplied by the reversing unit 13 with the front and back reversed. Then, the sheet is fed again to the engine body 10 and printed on the other side, whereby double-sided printing is performed.

The double-sided unit 16 used in this embodiment is
Paper path 161 without stopping supplied paper
And a second transport path for transporting the supplied sheets to a stacker 162 sequentially and holding the required number of sheets, stacking the required number of sheets, and sequentially transporting the sheets to the sheet supply side. It has a transport path.

Reference numeral 17 denotes a high-volume paper feeding unit corresponding to the above-described high-volume paper feeding device 5B, which can store about 2,000 sheets.

Reference numeral 18 denotes a large-volume paper discharging unit corresponding to the above-described large-volume paper discharging device 5D, which can store about 2,000 or more sheets.

By setting the number of sheets stored in the large-volume paper discharging unit 18 to be larger than the number of papers stored in the large-volume paper feeding unit 17, all the sheets supplied from the large-volume paper feeding unit 17 can be discharged.
18 can be collected.

Reference numeral 19 denotes a printer table on which the engine body 10 and its option unit are mounted. The inside of the printer table is used as a storage space 19a for the controller 2 described above.

Engine unit 10 and option unit (reversing unit 13, mail box 15, double-sided unit 16, high-volume feeding unit 17,
The mass discharge unit 18) is connected by the aforementioned engine option interface (EOI / F).

Further, it is possible to configure a system by omitting a part of these units, or replacing or adding various option units other than these units with the above-mentioned units.

Here, a printing operation by each unit in the engine body 10 will be briefly described.

As the paper supply source, one of the upper paper feed cassette 11, the lower paper feed cassette 12, the high-volume paper feed unit 17, and the duplex paper unit 16 (only during refeeding) of the engine body 10 is selected and the paper is supplied. Then, it stands by at the position where it is held between the registration roller pair 108.

On the other hand, the photosensitive drum 101 rotates in the direction indicated by the arrow, and the laser beam modulated according to the video signal by the optical writing unit 103 is mainly applied in the drum axial direction on the surface charged by the charging charger 102. Exposure is performed by irradiating while scanning to form a latent image.

The latent image is developed with toner from the developing device 104,
The toner image is transferred to a sheet fed to the image transfer unit at a predetermined timing by a pair of registration rollers 108 by a transfer separation charger 105, and the transferred sheet is separated from the surface of the photosensitive drum 101. Let it.

The sheet on which the image has been transferred is conveyed to the fixing unit 107, where the sheet is heated and fixed by a fixing roller and a pressure roller heated to a certain temperature, and then sent to the reversing unit 13.

The sheet discharged from the engine body 10 and sent to the reversing unit 13 is sent out from one of the three outlets A, B, and C at the upper side, the side, and the lower side. It is discharged to the mail box 15 and the duplex unit 16.

If the paper is ejected to the duplex unit 16,
The sheet is re-supplied to the engine body 10 through one of the second conveyance paths, or is discharged to the mass discharge unit 18.

Next, FIG. 13 shows a block configuration of the engine main body 10 and an engine control section (engine driver) 30 for controlling the above-mentioned option units connected thereto.

The CPU 31 is a central processing unit that controls the engine control unit 30 as a whole, and uses a general-purpose 8-bit microcomputer.

Reference numeral 32 denotes a program ROM, which stores a microcode for controlling the sequence of the engine body 10 and the connection with the controller 2 and each of the above-mentioned units (engine option units).

33 is for storing control data and engine status, etc.
RAM.

Reference numeral 34 denotes an interval timer for creating a basic time for controlling the sequence of the engine.

35 is engine option interface (EOI /
F), which is a serial interface for connecting the inverter unit 13, the mail box 15, the double-sided unit 16, the large-volume paper feeding unit 17, the large-volume paper ejection unit 18 and the like, which are option units, with a common line. Therefore, it has a serial communication function.

Each option unit has the device described above.
An ID is set, and at the time of communication between the engine control unit 30 and each of the option units 13, 15 to 18, the other unit is specified by transmitting a command to which a logical ID to which the device ID is assigned is added. And receives a response from the unit.

Reference numeral 36 denotes a computer interface, which receives a command from the controller 2 via LPVI and informs the controller 2 of the state of the engine 3.

An optical control unit 37 receives the image signal (video data) sent from the controller 2 via the LPVI and controls the optical writing unit 103.

Reference numeral 38 denotes an A / D converter, which receives an analog signal from a thermistor (temperature sensor) of the image forming / paper transport unit 100 of the engine body 10 after being amplified by an operational amplifier 41, and which can be processed by the CPU 31. To a digital signal as follows.

The above-mentioned thermistor is for grasping the temperature condition in each unit and the like in the machine, and is provided at several places in the machine.

Reference numeral 39 denotes an I / O port, which drives a motor, a plunger, a clutch, and the like in the image forming / paper transport unit 100 of the engine body 10 via a driver 42 and a driver 43, and applies a high voltage to various chargers. And a signal from a sensor or a switch for detecting the state of the engine body 10 is amplified to a logical level via an amplifier 44.

Reference numeral 45 denotes a counter using a backup memory or a non-volatile RAM. The counter 45 is controlled by the CPU 31 to count the total number of prints, the number of maintenances and its time, the number of jams, the number of serviceman calls and the like, and stores the count value.

These units are connected to the CPU 31 by a CPU bus 40 including a data bus, a control bus, and an address bus.

Next, communication between the controller and the print engine will be described.

First, the communication conditions between the controller and the print engine are as follows.

1. Interface: Asynchronous serial I / F 2. Communication speed: 9600 baud 3. Parity bit: None 4. Stop bit: 1 Communication between controller and print engine via LPVI 4 types of signal / PETXD, / PERXD, / PEC
This is done by TS and / PEDTR.

These interface signals have been briefly described above, but will now be described in more detail.

(1) / PERXD This signal is a serial communication reception data signal line for sending a command from the controller to the print engine.

(2) / PETXD This signal is a serial communication transmission data signal line that sends a response and an event report from the print engine to the controller.

(3) / PEDTR This signal is a ready signal line for serial communication for command transmission. When this signal is "L", it indicates that the controller may send a command to the print engine.

The print engine is powered on or initialized (including when system configuration is established)
Except for this signal, this signal must be held low.

(4) / PECTS This signal is a serial communication ready signal line for transmitting a response or an event report. When this signal is "L", it indicates that the print engine may send a response or an event report to the controller.

The controller must hold this signal "L" except when the power is turned on or when the communication with the print engine cannot be performed.

If the print engine receives too many event reports while this signal is "H", it may discard old event reports.

Next, a communication protocol between the controller and the print engine will be briefly described.

Communication between the controller and the print engine is performed by transmitting a command from the controller to the print engine, receiving the command, and returning a response to the controller.

Each command is composed of a 1-byte argument and an operator. As shown in FIGS. 14A and 14B, the most significant bit of the argument is always "1".
The most significant bit of the operator is always "0".

The command sends the argument first and the operator later.

Arguments can also be omitted, in which case the print engine must correctly recognize the command without the argument.

If a command consisting of an Argument and an Operator (eg, a "Status Request" command) is issued by the controller without an Argument, the previous Argument of the same command is effectively in effect.

When the print engine receives the command, if there is no valid argument, the print engine defaults to a virtual argument.

The response is to send the information requested by the received command from the print engine to the controller.

The length of each response is 1 byte, and the most significant bit is "0" as shown in FIG. 14 (c). However, in the case of a response to the "illegal command" shown in FIG. 9D, all bits are "1".

Event reports show events (options such as occurrence of jams and supply shortage) in the option unit and print engine.
When an error occurs, the print engine sends information not requested to the controller as a response.

Each event report includes one as shown in FIG.
It has a length of one byte and its most significant bit is "1".

Whether this event report can be generated or not is made by the controller using the 'ETB' command.

In this embodiment, the types of commands transmitted by the controller are as follows, and there are 13 basic commands and 3 enhance commands.

<Basic command> 1. Status request 'ENQ' 2. Ink eye input tray condition 'SI' 3. Ink eye output tray condition 'SO' 4. Ink eye paper size of input tray 'EM' 5 . * Feed start 'FF' 6. * Print start 'VT' 7. * Input tray select 'DC1' 8. * Output tray select 'DC2' 9. Event report enable 'ETB' 10. * Print engine mode Set 'DC4' 11. * Paper size Set 'DC3' 12.Ink eye extruded paper ID (Inquire e
xited paper ID) 'ACK' 13. Reset 'CAN'<Enhancecommand> 14. Assigned device ID 'FS' 15. Inquiry assigned Device ID 'GS' 16. Inquiry Communication Active
Device ID 'RS' Of the above commands, those marked with * are stored in the command buffer and executed sequentially.

However, as for the commands of "Input tray select", "Output tray select", "Print engine mode set" and "Paper size set", if the command with the argument is accompanied by another command with an argument. If neither the "feed start" command nor the "print start" command follows before, the previous command is erased from the command buffer and becomes ineffective.

This means that if no 'FF' or 'VT' command follows, the tray, paper size or mode specified by the command will be the selected tray, selected paper size or selected mode. It does not mean

These commands are not valid for the previous “feed start” command or “print start” command.

The print engine sets the mode or status specified by the "input tray select", "output tray select", "print engine mode select", or "paper size set" command, and then uses these commands. Hold until status or mode is reselected.

The print engine never clears the contents of the command queue itself, but clears it with a command received from the control. Also, the 'FF' and 'VT' commands in the command buffer are erased at the start of their execution.

If the mode set and tray select are done properly and a sufficient number of 'FF' and 'VT' commands are stored in the command buffer, or 'FF' and 'VT' commands are appropriated by the controller. When issued at time intervals, the print engine executes these commands at maximum throughput (print speed).

A general command transmission sequence for the controller to request the print engine to execute printing is shown below.

1) Input tray selection An input tray including a double-sided input unit is selected. If the argument is omitted, the previous tray is valid.

The previous tray is also effective when the "input tray select" command is not issued.

3) Output tray selection An output tray including a duplex output unit is selected. If the argument is omitted, the previous tray is valid.

The previous tray is also effective when the "output tray select" command is not issued.

3) Feed request Send a "feed start" command. If this command has not been issued, the next "print start" command is valid for feed and print.

4) Print request Send a "print start" command.

If the “/ PRINT signal ignore flag” of “system current mode” is “0”, the controller also
It is also possible to request the print engine to execute printing with the "print request sequence hand-shake by NT and PREADY". Note that "/" preceding each signal means negative logic (low active).

This request is executed prior to the 'FF' and 'VT' commands. However, it is not stacked in the command queue. The print request sequence is valid only in real-time execution.

If the controller does not request printing with the / PRINT signal, the print engine mode is set to “ignore / PRINT signal” by issuing the 'DC4' command.
Mode should be set.

If the print engine receives the / PRINT signal and 'FF' and 'V
If a print request is received by both the T 'command and the command timing and sequence, a serious error may occur in the execution of the command.

The controller queries the print engine's current status (eg, the currently active input tray) just prior to requesting the print engine to perform printing via the / PRINT signal line.

A response to a command (command marked with *) stored in the command buffer is transmitted from the print engine immediately after receiving the command, not when the command is executed.

As such, the content of the response may sometimes differ from the actual status of the execution of the command. For example, after responding to the “Input Tray Select” command, if a cassette of a different size is mounted on the selected input tray, the actual paper size will be “Input Select”.
This is different from the size sent by the print engine in response to the command.

In such a case, the status of the print engine becomes an error state (input size mismatch).

For the "Status Request" command, which queries the currently active input tray, the currently active output tray, and the current mode status of the system, the print engine issues the "FF" command immediately after the start of execution or the second command. Answer the currently active tray specified for the mode 'VT' command, or answer the currently active mode at that time.

The print engine will not respond to the tray code or mode specified by a command that has not been executed in the command queue.

The capacity of the command buffer should be as large as possible, depending on the maximum print speed of the print engine, but if the print speed of the print engine is less than 20 pages / minute, it will be equivalent to 32 papers Having enough capacity is enough.

If the control wants to change the currently active input or output tray because the paper is empty or full while the print engine is executing a 'FF' or 'VT' command. The controller first issues a "command buffer clear" command and then reselects a new input or output tray.

In some cases, the print engine must predict the status of each unit and predict a response in response to the predicted status.

For example, a double-sided unit overflow or empty paper status indicates that the previous command was still in the command buffer and has not yet been executed.
Predicted to depend on previous commands.

Communication between Print Engine and Option Next, communication between the print engine and an option unit as various additional devices will be described.

The communication conditions between the print engine and the option unit are the same as the communication conditions between the controller and the print engine described above.

1. Interface: Asynchronous serial I / F 2. Communication speed: 9600 baud 3. Parity bit: None 4. Stop bit: 1 The communication protocol was briefly described earlier in the description of the basic system configuration. I will explain this in more detail.

Also in this case, communication from the print engine to the option unit is performed by transmitting a command, and communication from the option unit to the print engine is performed by transmitting a response.

An example of the format of this command and response is shown in FIG.

One command is by connexion configured operator and Agiyumento, b ₇ ~b ₅ of Agiyumento is always "111", also shows logical ID code option Chillon Units - To communicate the operator b ₇ ~b ₅ print engine .

The operator also serves as the end of one instruction.

The types of commands used in this embodiment are as follows.

<Basic command> 1. Inquiry unit status (Inquire unit status) “*** 10001” 2. Inquire paper size “*** 10010” 3. Inquiry unit condition (Inquire unit condition) "*** 10011" 4.Ink iron unit availability (Inquire unit availability) "*** 10100" 5.Ink eye unit specification specification # 1 (Inquire unit specification # 1) "*** 10101" 6.Ink Iron Unit Specification # 2 (Inquire unit specification # 2) "*** 10110" 7. Ink Unit Unit specification # 3 (Inquire unit specification # 3) "*** 10111" 8. Ink Eye Excited Paper ID (Inquire exited paper ID) “*** 11000” 9. Inquiry unit firmware version (Inquire u nit firmware version) “*** 11111” 10.Tray selection “*** 00001” 11.Mode setting “*** 00010” 12.Paper size setting “* ** 00011 "13.Paper feed start" *** 00100 "14.Paper feed stop" *** 00101 "15.Paper feed restart" ** * 00110 "16.Paper eject start" *** 01000 "17.Paper eject end" *** 01001 "18.Initializing (*** 01110) 19.Abort (Abort) “*** 01111” 20. Length of print engine path (*** 01010) 21. Registration distance (Registrationt distance) “*** 01011” 22. Transport velocity “*** 01100” < Enhance command> 23. Assign Device ID “*** 11001” 24. Inquire assigned Device ID “*** 11010” 25. Inquire device ID (Inquire Device ID) "*** 11011" These commands are always executed in real time by the option unit.

Each option unit has a specific tray selection, mode set, paper size set, print engine
Path length, resist distance, transfer speed, and specified device ID
Mode, status, or designation is retained until re-selected by these commands.

Commands must be sent to the operator first with arguments, but the arguments of the command consisting of arguments and operators can be omitted, and the option unit must correctly recognize commands without arguments.

For example, if the print engine sends a command without arguments, such as a command such as the “Inquire Unit Status” command, the argument before the same command to the same logical ID unit is valid as the effective argument. is there.

However, the “paper eject start” command,
The “assign device ID” command shown in FIG. 15 (b) and the “inquire device I” shown in FIG.
Except for the D "command. In these commands, the previous argument is never valid.

Also, arguments for other commands and other logical
Arguments to the ID unit are invalid in any case.

If there is no valid argument on the option unit side when the command is received, the option unit must take the default value as the effective argument.

The response is a message sent from the option unit to the print engine, and indicates that the command has been received. All of the response is the length of one byte, b ₇ is summer to "0".

If the option unit does not support the function of the received command, the option unit must return <7Fhex>, that is, "01111111" as a response.

FIG. 15B shows an “assign device ID” command transmitted when the print engine assigns a device ID to a logical ID, and a format of a response transmitted from the option unit that has received the command.

This b ₃ ~b ₀ arguments command enters the device ID code is assigned, the operator of b ₇ ~b
₅ (indicated by ***) contains the logical ID code to be assigned.

For example, if this command is “111 × 0010,00011001”, “device ID“ 0010 ”(INP # 3: mass paper feeding unit 17, corresponding to mass paper feeding device 5B in FIG. 3) is assigned a logical ID.
Assign it as "000" (IN # 1). "

In response to this, the CPU of the option unit with the device ID “0010” (the large-volume sheet feeding unit 17 in the above example) recognizes this and returns a response of “00000010”.

This means that “device ID“ 0010 ”is changed to logical ID“ 000 ”(IN
# 1). "

Here, no Units - type code to the device ID code, two bits of b _6, b ₅ logical ID code is Units - type code, discrimination since in this example, "00" represents the Imp bracts Units - it can.

FIG. 15 (c) shows a command for inquiring the device ID of an option unit assigned to a specific logical ID.
Shows the "D" command and its response. This command is an operator-only command without an argument. For example, "00011010" queries each option unit as to what is assigned to the logical ID "000". Will do.

If the option unit having the assigned device ID is a large-volume feeder, a response of “00000010” (input option unit “0010” is assigned to the logical ID IN # 1) is then sent. Will return.

FIG. 15 (d) shows an "inquire device ID" command for inquiring whether or not a specific option unit can communicate, and a response thereto.

The device ID code to query the b ₃ ~b ₀ argument to this command, put Units - Type code to b _7, b ₆ operators. For example, “111 × 0010,00 × 11011”
Is a command for inquiring whether the input option unit "0010" (mass feed unit 17) is communicable.

If the large-volume sheet feeding unit 17 is assigned, a response of “000 × 0010” is returned.

As described above, the command operators b _{7 to} b ₅
Is the global ID address "110", it indicates that the command is a global ID command.

When a global ID command is transmitted from the print engine, all of the option units in a communicable state must execute the command according to this command as much as possible. However, the option unit does not issue a response to this command, and the print engine can issue the next command without waiting for a response.

Initial Setup Next, the initial setup of this laser printer system will be described with reference to FIGS. 16 and 17. FIG.

FIG. 16 shows the relationship between the transmission and reception of signals between the operation panel, the host system, the controller, the print engine, and each of the option units at the time of initialization, and FIG. 17 is a flowchart showing the operation of the print engine.

Referring mainly to FIG. 17, when the power is turned on (power is turned on) and when an initialization command is received from the controller, the print engine sends the initialization command to all the additional devices (option units).

This initialization command may be a global ID command.

Then, the print engine itself performs initialization and self-diagnosis to perform initialization, and all communicable additional devices that have received the initialization command also perform initialization and self-diagnosis to initialize.

Thereafter, it is determined whether or not this printer system is an enhanced system. If YES, the device is an enhanced system. Therefore, the communication enable / disable state of all device IDs (48 IDs) is checked twice or more, and each device ID is checked. When the state becomes the same as the previous cycle, the state of each device ID is determined.

The reason why the results of the two confirmations are coincident is to prevent the state of the additional device in an unstable state such as a transient state when the power is turned on or off from being erroneously determined.

Next, one device ID is assigned to one logical ID in priority order, and a system configuration is established.

 Here, the priorities include the following 1 and 2.

Priority 1: Communication active device Priority 2: Younger device ID code On the other hand, if it is not an enhanced system, it is a basic system, so all logical ID units (5 IDs)
Is confirmed twice or more, and when the state of each logical ID unit becomes the same as the previous cycle, the state of each additional device is determined, and the system configuration is established.

The print engine must not issue any command to any option unit during initialization of the print engine itself.

Also, while any option unit is initializing itself, it must not send any response to the print engine.

After establishing the system configuration,
The print engine can communicate with the controller, but until then, the / PEDTR signal, which is a communication ready signal with the controller, must be turned off.

<< Points Related to the Present Invention >> Next, points relating to the present invention in the above-described laser printer system will be described in detail.

FIGS. 18 to 20 show a detailed flow of communication for the controller 2 to confirm the status information of the print engine 3 and a specific option unit.

FIG. 21 shows the print engine status code responded by the print engine and its contents in FIG.
Shows the option input / output unit status codes to which the option unit responds and their contents.

The outline of communication between the controller, the print engine, and the option unit will be described with reference to these drawings.

First, as shown in FIG. 18, a "printer general status" code (a code for asking the general condition of the printer) is sent from the controller to the engine. Bit b _{0 of} this command
Bb ₆ = 0 indicates a request for a general status.

Engine contrast, returns the response, shows the overview of the b ₀ ~b of each bit of the ₆ "1" or "0" each of printer status.

Next, the controller sends a "print engine status" command to the engine for asking the status of the engine unit.

If bit b ₆ is "0" for this command, the engine to the controller, priority is shown in top priority (FIG. 21 among the states of the engine unit that currently exist "print engine status code" 1 → Responding information positioned with high 64) uppermost, if there is no information to be returned if the bit b ₆ of the response to "1", bit b ₅ ~b ₀ sends a response remains undefined.

Controller If the bit b ₆ is "1" of the response, to stop the question of the status of the engine at that time, goes to the state inquiry to the next Yunitsuto. If the bit b ₆ is "0" in response, because still known state information to be is present in the status punishment Hua of the engine and sends the code to ask the status of the engine again.

At this time, since the bit b ₆ of the command is not the highest priority information again to "1" is sent, the bit b ₆ to ask the state information of the next priority was last response to "1"" The command of "print engine status" is transmitted, and the next priority status information is obtained by the response from the engine.

The controller must keep asking until bit _{6 of} the response becomes "1". Thus, the controller can know all the current engine states.

The status code returned by the response is
As shown in FIG. 21, it follows a table agreed between the engine and the controller.

After the status inquiry to the engine is completed, the controller proceeds to the engine to inquire the status of each additional device (option unit).

As for the inquiry command “input unit # 1 status”, bits b _{5 to} b ₀ are “001001”.

When the print engine receives this, it sends an "inquiry unit status" command to the input unit # 1 and receives a response from the input unit # 1.

During the exchange of the status information during this time, like the exchange between the controller and the engine, the command on the inquiring side has a bit (b ₆ ) indicating whether or not the next priority information is to be asked. bit indicating whether the status punishment Hua for state storage is empty in (b ₆₎ has, until it can be seen that the status punishment Hua has decreased to the sky, the controller Imp engine bracts Units - # 1
Query the status of.

The status code returned by the response is
As shown in FIG. 22, a table is established between the engine, the controller and the options.

The engine is thus input unit # 1
The status information obtained from is sent to the controller as a response.

In the same manner, the controller passes through the engine,
The status of the input unit # 2, output unit # 1, output unit # 2, and double-sided unit is sequentially inquired.

Here, the response example of the engine unit status
Shown in the figure.

In this example, in the print engine, the paper feed tray in use has no paper (B) and the cover open # 1
(C) and paper jam # 1 (D) occur simultaneously,
Then, after the toner shortage (addition required) (A) occurs, the absence of paper in the paper tray in use (B) is resolved, and then (C) and (D) are resolved simultaneously. It is assumed that it has been resolved. The priority of each status (state) is (D) (C) (B) (A).

In the figure, 'ENQ' is the “print engine status” command, and INPS is the bit b of the command argument.
₆ (a flag for asking the next priority when the "1"), SBE is a bit b ₆ of the response ( "1" flag indicating the status cross Hua is empty when).

Next, the details of the “printer general status” command and the response thereto will be described.

This command is used when the argument is 80 in hex code.
_H, since (in hex code 05 _H) operator 'ENQ' is represented as 80 _H 'ENQ', status request
One of the commands inquires about the general status of the engine system including the option unit.

Each bit of the response indicating the status from the print engine to this command is as follows.

Response (status): b ₇ : “0” b ₆ : Paper is present in the paper path of the system b ₅ : Paper ejection ID is in the paper ejection ID buffer b ₄ : Paper jam fixed b ₃ : Print start ready (registration point ready) b ₂ : Feeding started (during feeding) b ₁ : Status group code 1 b ₀ : Status group code 0 (Explanation) 1. “There is paper in the system paper path” Any of the input trays (excluding double-sided units) )
When there is any paper in the engine system paper path including the double-sided path, the paper supply of which has been started and the output of which has not been completed in any of the output trays (excluding the double-sided unit). The flag is set to "1".

If there is no paper in the paper path of the engine system, this flag is set to "0".

2. The flag of "paper discharge ID exists in paper discharge ID buffer" is set to "1" when one sheet of paper has been discharged to an output tray other than the duplex unit. This flag is set to "0" when the discharge ID buffer becomes empty due to the issuance of the event report # 3 or the issuance of a response to the 'ACK' command.

If the paper ejection ID still remains in the paper ejection ID buffer, this flag remains "1", indicating that the paper ejection ID buffer is not empty.

The controller is “Ink Eye Exit Paper”
By issuing the "ID", that is, the 'ACK' command, the paper ejection ID can be queried.

3. "Paper jam fixation" In some cases, even if a jam (paper jam) occurs in the engine stem during printing, paper other than the jammed paper may be transported and discharged to the output tray.

Then, the jammed paper is fixed (fixed) when the discharge of the other paper is completed. The engine sets this flag to '1' when such jammed paper is fixed.

When this flag is "1", the controller can ask the ID number of the jam paper by issuing a status request command.

The engine sets this flag to "0" when it is confirmed that no paper remains in the paper path after the jam recovery operation is performed.

4. "Print start ready" This flag is set to "1" when the fed paper is ready to be printed at the registration position.
This flag is set to "0" when no paper is waiting for printing at the registration position.

When this flag is "1", the engine starts printing to execute the 'VT' command.

The controller may send a print start command without this flag depending on the correct print sequence.

5. "Feed start (during feeding)" This flag is set to "1" when the engine starts feeding one sheet of paper.

This flag is set to "0" when the engine can start feeding the next paper from the currently used input tray. The timing of setting this flag to "0" depends on what tray is to be used next.

6. "Status group code" This 2-bit flag indicates the general status of all engine systems.

 The meanings of these flags are as shown in FIG.

The status indicated with this status group code depends on the event report enabled state. This means that the status group code changes according to the bits b ₁ and b ₀ of the argument of the 'ETB' command which is a command of “event report enable”.

The relationship between the bits b ₁ and b ₀ and the contents of the general status indicated with the status
See Figure 25.

Here, “ETB” of “Event Report Enable”
The command and its response will be described with reference to FIGS. 26 (A) and (B).

The 'ETB' command transmitted from the controller to the engine is a command for enabling or disabling the engine to transmit various event reports, respectively.

The format: "Agiyumento" + 'ETB'<17hex>_{Agiyumento; b 7: "1" b} 6 ~b 2: Event Report Number b _1, b _0: Events enable condition Response: "enable flag" b _7: "0" b _{6 to} b ₂ : Event report number b ₁ , b ₀ : Event report enabling condition Default: In the default enable state immediately after power-up or initial setting, bits b ₁ and b ₀ are set to “00” for all event report numbers. And the engine is prohibited from sending any event reports.

Preferably, the controller checks the diagnostic results of the engine after the initialization is completed. Therefore, the 'ETB' command is set to the default to prohibit the event report from being issued by the engine. Then, after initialization is complete, the controller queries the status of the engine or enables the issuance of an event report.

Transmission of Numerical Information By the way, the above-described printer system according to the present invention uses numerical values such as the total number of prints, the number of maintenances and the time, the number of jams, and the number of serviceman calls obtained by the counter 45 shown in FIG. Information is transmitted from the engine 3 to the controller 2, and the controller 2 can perform various controls based on the transmitted numerical information.

That is, when the above-mentioned numerical information becomes necessary, the controller 2 sends a command for numerical inquiry to the engine 3 by the / PERXD signal of LPVI shown in FIG.

The engine 3 which has received this command returns the obtained numerical information to the controller 2 as a response by the PETDD signal. The controller 2 performs display and various controls based on the numerical information returned from the engine 3.

 FIG. 27 shows the configuration of the above command and response.

The command for numerical value inquiry sent from the controller 2 to the engine 3 is composed of an 8-bit unit and an operator as shown in FIG. 27 (A).

The operator of the bit b ₇ ~b ₀ is "00000101", is represented by hex code is "05 _H", it referred to as 'ENQ'.

 The bits of the argyument are as follows.

b ₇ : Always “1” b ₆ : Next position (non-top: INHOV) flag b _{5 to} b ₀ : Numerical information inquiry status number (To inquire about the total number of prints,
“110000”) b For the next position inquiry flag of ₆ , if this flag is “0”, the number of digits and the numerical value of the most significant value are requested, and if “1”, the number of digits of the next lower digit after the previous digit And a numerical value.

Here, the most significant value is “0” for the first time when viewed from the largest digit side of numerical information represented by a predetermined number of digits.
Is the value of the digit where the value other than That is, if the numerical information is “0045786”, the highest value is “4”.

The status number for inquiring numerical information is bit b ₅
The contents of ~b _0, is intended to identify the type of numerical information to be requested, for example, the contents of bit b ₅ ~b ₀ is "110000"
If so, the request is for the total number of prints (the number of pages).

On the other hand, the response returned from the engine 3 to the controller 2 has an 8-bit configuration as shown in FIG. 27 (B), and each bit is as follows.

b ₇ : Always “0” b _{6 to} b ₄ : Number of decimal digits (decimal order) b _{3 to} b ₀ : Numerical value of each digit (variable) Number of decimal digits (10 to the power of x: x = 0) 7) are bits b _{6 to} b ₄
("000" to "111").

Numerical value of each digit, bit b ₃ content of _{~b 0 ( "0000" ~ "} 100
1 ") is expressed Te Niyotsu. The relationship between the contents of the bit b ₃ ~b ₀ and numeric value represented Te cowpea it is decreased to the binary coded decimal as shown in the following table.

Next, the transmission and reception of commands and responses between the controller 2 and the engine 3 will be described based on specific examples.

When the controller 2 requests the total number of prints from the engine 3 as numerical information, the controller 2 first transmits "10110000"'ENQ' to the engine 3 as a command.

This command requests the numerical information representing the Yotsute total number of prints that bit b ₅ ~b ₀ of Agiyumento is "110000", the most significant value each cowpea that bit b ₆ is "0" Is demanding.

Upon receiving this command, the engine 3 determines that the highest value of the total number of prints has been requested, and if the count value of the total number of prints of the counter 45 is “00453786”, for example, 01
010100 "to the controller 2.

This response, bit b ₆ ~b ₄ is Yotsute to be "101", the number of digits to be transmitted 10 ⁵ digits, i.e. 6
It indicates that a digit represents the most significant value is "4" by a bit b ₃ ~b ₀ is "0100".

Next, the controller 2 inquires of the command “11110000” in which the bit b ₆ of the command argument is set to “1” in order to inquire of the next highest value (numerical value of the next lower digit) of the highest value sent from the engine 3. 'ENQ' is sent to engine 3.

In response to this command, the engine 3 determines that the next value of the previously transmitted numerical value has been requested, and indicates that the numerical value of the fifth digit following the last transmitted most significant digit is “5”. A response “01000101” is transmitted to the controller 2.

Controller 2 in this way, successively, numerical information of the command "11110000"'ENQ' querying the value of the next digit is sent to the engine 3, to "6" from the engine 3 10 ⁰ digits, namely the first digit And the numerical information is RA
Store in M22.

After sending a response indicating that the first digit is “6” to the controller 2, the engine 3 sends a command “1111” for further inquiring the next value from the controller 2.
If 0000 "'ENQ' is sent, the first digit is" 6 "
Is transmitted to the controller 2 repeatedly.

FIG. 28 is a flowchart showing the numerical information request processing of the controller 2.

In this example, it is assumed that information up to the 10th power digit of the desired numerical information of a plurality of digits is required.

First, the controller 2 sends the commands to the content to identify the bit b ₅ ~b ₀ a type of numerical information bit b ₆ is "0" Agiyumento the engine 3, the uppermost value of the numerical information of interest Request.

Then, the controller 2 receives the response from the engine 3 and inputs the number of digits of the highest value of the requested numerical information and the numerical value, and stores the input data in the RAM 2 shown in FIG.
Store in 2.

Next, the controller 2 compares this x with the above z, assuming that the number of digits of the currently input numerical value is 10 to the power of x in order to confirm whether all necessary numerical information has been input. Then, it is determined whether or not z ≧ x.

Since not completed the input of the numerical information up to the digit that require long NO, the controller 2 sends a command to "1" to bit b ₆ of Agiyumento the engine 3, next order value (previous Next lower digit of the number).
The number of digits next to the most significant digit and the numerical value are input by a response from the engine 3, and the input data is stored in the RAM 22.

The controller 2 repeats such an operation, and sequentially inputs the number of lower digits and the numerical value thereof one digit at a time. Then, when the information of the required digit is input, the judgment of z ≧ x is made.
It becomes YES and ends the processing.

As described above, according to the above-described embodiment, the controller 2 can receive the numerical information from the engine 3 for each digit, and furthermore, the unnecessary numerical information in the higher digit than the highest digit (see the above description). In the example, the top two in “00453786”
The digit “00”) is not transmitted to the controller 2.

Therefore, the controller 2 can input only the necessary numerical information in a short time, and the RAM 22 of the input numerical information can be used.
Processing of numerical information such as storage in the storage can be completed in a short time.

Furthermore, when the controller 2 inputs the numerical information is enough if sending two commands bit b ₆ of Agiyumento is "0" or "1" to the engine 3, for input of each digit of numerical information Since there is no need to transmit a different command corresponding to the number of digits, the command transmission / reception function can be simplified.

In the above embodiment, the controller 2 and the engine 3
Although the description has been given of the transmission of numerical information between the controllers, the present invention can be similarly applied to the transmission of numerical information between the controller 2 and the host system 1.

Further, as shown in FIG. 29, in a laser printer system in which a controller 2 'is built in a host system 1' and is connected to the engine 3 by LPVI, a connection between the controller 2 'and the engine 3 is also provided. The present invention can also be applied to the transmission of numerical information between the host system 1 'and the main body of the laser printer.

Further, the present invention is not limited to a laser printer system,
The present invention is also applicable to an image forming system using another page printer, a digital copying machine, a facsimile machine, or the like.

〔The invention's effect〕

As described above, the image forming system according to the present invention uses the type of status inquiry command (status request command) from the image processing device (controller) or the host system to provide information on the image forming device (print engine) side. Can be successively returned according to the priority order, so that the number of states that the image processing apparatus can know is not limited, and all the states at that time can be known.

Therefore, the image processing apparatus can accurately judge the situation of the entire system, and can accurately inform the operator of the entire situation of the system through the host system. It is also possible to efficiently cancel at once.

Further, since it becomes possible to transmit only the necessary digit information of the numerical information represented by a plurality of digits between the image processing apparatus or the host system and the image forming apparatus, the transmission time and the transmission time of the numerical information can be increased. The processing time of the given numerical information can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a system configuration of a basic embodiment of the present invention, FIG. 2 is an explanatory diagram showing a configuration example of a command issued from the image forming apparatus main body to each additional apparatus, and FIG. FIG. 4 is a block diagram showing a system configuration of another basic embodiment of the present invention, FIG. 4 is a block diagram showing a configuration of a laser printer system according to an embodiment of the present invention, and FIG. 5 is a controller 2 shown in FIG. FIG. 6 is a block diagram showing the configuration of FIG.
FIG. 7 is a block diagram showing the relationship with each buffer and file in FIG. 7. FIG. 7 is an external view showing a specific example of the operation panel 25 in FIG. 5, and FIG. FIG. 9 is an explanatory diagram showing a file format of the IC card 6 in FIG. 5, FIG. 10 is an explanatory diagram of LPVI signals in this embodiment, and FIG. 11 is a diagram showing a print area in this embodiment. FIG. 12 is an explanatory diagram showing the relationship between image signals, FIG. 12 is a schematic diagram of an engine body constituting the printer system, and a schematic diagram of a mechanism section of various option units connected to the engine body, and FIG. 13 is a block diagram showing a configuration of the engine control section. FIG. 14, FIG. 14 is an explanatory diagram of commands and responses used between the controller and the print engine, and FIG. 15 is used for communication between the print engine and each option unit. FIG. 16 is an explanatory diagram of commands and responses, FIG. 16 is a flowchart showing the operation of the entire system at the time of power-on and initialization execution in this embodiment, FIG. 17 is a flowchart showing the operation of the print engine at that time, FIG. FIGS. 20 to 20 are flow charts showing the exchange of commands and responses when the status of the print engine and the option unit are confirmed by the controller. FIGS. 21 and 22 show the status of the print engine used for the communication. FIG. 23 is an explanatory diagram showing an example of a response of an engine unit status, FIG. 24 is an explanatory diagram showing a relationship between a status group code and a status level represented thereby, Fig. 25 shows the bits b ₁ and b of the argument of the 'ETB' command.
26A and 26B are explanatory diagrams showing the relationship between the contents of the general status indicated by ₀ and the status group code, etc. FIGS. FIG. 27 is an explanatory diagram of a command and a response for transmitting numerical information between the controller and the engine, FIG. 28 is a flowchart of a numerical information request process of the controller according to an embodiment of the present invention, and FIG. 29 is another diagram of the present invention. FIG. 1 is a block diagram illustrating a configuration of a laser printer system according to an embodiment. 1, 1 ': Host system 2, 2': Controller (image processing unit) 3: Print engine (image forming unit) 4: Image forming apparatus (printer) main body 5, 5A to 5G: Various additional devices 10 Engine body 13 Reversing device (reversing paper ejection device) 15 Mail box (multi-stage paper ejection device) 16 Double-sided unit (double-sided conveyance device) 17 Large-volume paper feeding unit (large-volume paper feeding device) 18: Large-volume paper discharge unit (Large-volume paper-ejecting device) 19: Printer table 20: CPU of controller, 25: Operation panel 27: Option interface 29: Engine interface 30: Engine control unit ( (Engine driver) 31 ... CPU of engine control unit 35 ... engine option interface 36 ... controller interface 45 ... counter

Claims (2)

(57) [Claims] 1. An image processing apparatus for receiving character information or image information from a host system to generate image image information, and an image forming apparatus for receiving the image image information from the image processing apparatus and forming an image on a recording medium And an image forming system connected through an interface, wherein the image processing apparatus inquires the image forming apparatus of a code corresponding to information positioned at the top of the valid information, Means for transmitting a command having a flag indicating whether to inquire about a code corresponding to information positioned next to the set information, the image forming apparatus, when receiving the command, valid information according to the flag Code corresponding to the information positioned at the top of the list or information positioned next to the information Image forming system characterized by comprising means for returning to the image processing apparatus to the code corresponding to the. 2. An image forming system comprising: a host system connected to an image forming apparatus which receives image image information from the host system and forms an image on a recording medium via an interface; A flag indicating whether the image forming apparatus is to be queried for a code corresponding to the information positioned at the top of the valid information or to query a code corresponding to the information positioned next to the previously responded information. Means for transmitting a command having the following: when the image forming apparatus receives the command, the code corresponding to the information positioned at the top of the valid information according to the flag or the information of the information previously responded to Next, means for returning a code corresponding to the positioned information to the host system is provided. That image forming system.