JPH04366972A - Image forming device - Google Patents

Abstract

PURPOSE: To provide a device which is intelligent and monitors its own performance to be adapted to the changing condition. CONSTITUTION: In an onboard diagnosis and control system provided in an image forming device, plural sensors provide an expert system with information so that the whole of a selected area of the performance of a subsystem and the performance of a machine can be monitored. The expert system provides a real time control system with set parameters by a knowledge base and an interference mechanism, and this control system controls component members and the subsystem of the image forming device. As the result, the operation of the machine is adjusted to reduce or eliminate paper jam.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to machines and artificial intelligence (A
Regarding machine control using I), more specifically, diagnosing,
and an on-board expert system for controlling operations based on this diagnosis, such as copying machines and printers, for copying images or producing images based on electronic data streams. Regarding equipment.

0002

BACKGROUND OF THE INVENTION Artificial intelligence (AI) is a scientific offshoot resulting from the combination of cognition and computer science. Computers were originally used to manipulate numbers (data), but are now being used to manipulate ideas (knowledge). Trends and answers are inferred by the assimilation of observed and sensed facts, just as numbers are added and subtracted to arrive at a total. Computer systems are being developed to present thought processes previously available only to humans.

Research in AI has led to insights into human thought processes as well as practical systems for solving problems in the workplace, school, and home. An "expert system" is one use of AI technology to obtain practical results. Expert systems solve problems through the manipulation of knowledge. An expert system is a reasoning mechanism that has an underlying knowledge base on which it operates. This knowledge base is compiled from the experience of experts in the field and coded into a computer language suitable for describing ideas and principles. The inference mechanism controls the flow of the program and creates an answer.

Reasoning mechanisms have recently become widely commercially available from many companies. These companies include Gold Hill Computers, Cambridge, Massachusetts, USA;
computers, Inc. ), Intellicorp, Mountain View, California
iCorp, Inc., and Technology Applications, Inc. (Technolog, Jacksonville, Florida).
y Applications, Inc. ), Technology Company (Tekn), Palo Alto, California
oledge, Inc. ), Neuron Data, Palo Alto, California
Data, Inc. ), and Texas Instruments (Texas I), Austin, Texas.
There is a company called ``instruments''. Two inference mechanisms are described in U.S. Pat. Nos. 4,658,370 and 4,648,04.
It is disclosed in No. 4.

[0005] In recent years, expert systems have been used in various fields such as agriculture, science, computer design, construction, finance, management, insurance, manufacturing, and so on. For example, U.S. Pat. No. 4,591,983 discloses an expert system for use in inventory management, and U.S. Pat.
No. 2,782 and No. 4,644,479 each disclose a diagnostic system for monitoring industrial systems such as steam turbine power plants.

[0006]Currently, in the market, "intelligent machine"
) (intelligent machines). This machine is "intelligent" in the way it works, that is, in the way it monitors its own performance and adapts to changing conditions.
) (intelligent). The machine is also perceived as "intelligent" by its operator due to its ability to "understand" and satisfy the operator's objectives. Further intelligence has been recognized for maximum reliability, which translates to minimizing unscheduled maintenance and machine downtime.

[0007] There are many machines on the market today that have some degree of "intelligence". The "intelligence" provided in these machines is generally made possible by providing conventional closed loop feedback control (CCLC) without the use of AI techniques or technology. Current CCLCs operate with real-time control and do not utilize heuristic learning to infer the problem or necessary corrective actions as parallel activities that supplement the CCLC system.

[0008] For example, in an image production device, such as a copying machine or a printer, which makes a copy of an original or creates an image based on supplied electronic data, a large number of subsystems are provided. , each of which performs one or more functions that work together incrementally to accomplish the overall goal of the machine or device (output a sheet containing the desired image). Currently commercially available imaging devices use control architectures that include conventional feedback control, such that the controlled subsystems operate according to preset parameters. C.C.
One problem with LC is that the behavior of these subsystems is determined before their use. Therefore, the parameters set for these subsystems only reflect experience during product development. That is, CCLC systems do not allow for adaptation to changing conditions and experience gained from machine operators in the field. For example, in closed loop xerographic process control, the charging voltage on the photoreceptor is a CCLC parameter. Therefore, the changing voltage on the photoreceptor is measured by a sensing device such as an electrometer. Unexpected electrometer malfunctions can result in incorrect xerographic process control, resulting in poor copy quality and other related problems. Generally, CCLC systems alone do not have the ability to actually detect malfunctions of the type described above and reject normal feedback controlled behavior. Although all efforts are typically made during product design and development to anticipate and overcome such potential problems, actual use of the product in the field may result in problems that were not considered during product development. Abnormal behavior such as calluses often occurs.

Another problem with the CCLC approach concerns its application. Due to the complexity of modern machines, such as copying machines, the control systems themselves become complex. For ease of handling, CCLCs are generally implemented at the subsystem or module level. This "subsystem" approach requires making assumptions about the nature and extent of interactions between different subsystems. Therefore, a typical CLC is
It is not possible to fully take into account the effects of all subsystem interactions. For example, if one subsystem fails to send its expected output to a conversing subsystem, it can disrupt the conversing subsystem's control system, unless this condition is considered in the design of the CCLC. There is a possibility of falling. As previously mentioned, all interactions of the subsystems are generally unknown until the machine is actually used in the field. Renovating any condition is expensive and time consuming. That is, because such problems were not anticipated, the CCLC system software is not flexible enough to facilitate rapid changes. Although conventional CLC systems are applicable to entire complex machines, the task becomes significantly more complex and difficult.

The aforementioned and other CCLC system-related problems require solutions that are more flexible than conventional CLC systems. Thus, the present invention includes a unique knowledge-based control architecture solution. The present invention combines certain AI techniques and techniques (particularly those involved in knowledge-based system development) and conventional CLC system techniques.

As previously mentioned, the use of expert systems is generally known, and this refers to the use of CCLC systems that do not use AI techniques or technology, but provide a degree of "intelligence" through customary closed-loop feedback. It is similar to U.S. Pat. A copying apparatus is disclosed. In U.S. Pat. No. 4,721,978, an alternative to measuring the amount of toner material used over time and simply resupplying the toner material only when a low level of toner material is detected. Then, the toner agent is replaced based on the measurement (column 8, lines 37-42 of the specification). U.S. Pat. No. 4,421,404 is directed to a document handling device job recovery technique, and the specification, at column 1, line 68, and column 3, lines 1-7, states that a microprocessor routine is included within the reproduction device. It is disclosed that the microprocessor "supports the establishment of a degree of 'artificial intelligence' to anticipate machine user requirements in document feeder operation, editing, and other areas." has been done. U.S. Pat. No. 4,511,242 discloses an electronic form alignment device, and the specification, from column 2, line 65 to column 3, line 17, states that it establishes "a degree of artificial intelligence." It is stated that a microprocessor is used. Although these patents use some degree of AI, these patents only rely on conventional CLC systems and therefore have all of the aforementioned problems associated therewith.

[0012] US Pat. No. 4,642,782, No. 4,
No. 644,479, No. 4,649,515, and No. 4
, 697,243 discloses an apparatus that performs diagnostic functions using an expert system. US Pat. No. 4,642,782 discloses a computer diagnostic device for industrial or other types of operating systems. Rulebases related to the operating system being diagnosed are stored in memory. This rule base is established by experts in the field related to diagnosis. Sensors monitor operating parameters of the system and provide output signals that are sent to diagnostic equipment. General information about the operating system and detailed information about its components.
An overall "health status" is provided to the operator via the display. U.S. Patent No. 4,649,515 states:
A system for developing generic facilities for building knowledge-based systems is disclosed. The system can be used in an interactive mode to assist repair personnel in diagnosing system malfunctions. U.S. Pat. No. 4,644,479 discloses a diagnostic apparatus that utilizes a diagnostic expert system to monitor a steam turbine power plant. U.S. Patent No. 4,697,243
No. 6,933,902 discloses a method of using an expert system, in which the expert system having a knowledge base of elevator fault repair information is used interactively by remotely located elevator repair personnel to diagnose malfunctions. The expert systems disclosed in the aforementioned patents perform diagnostic functions but do not provide self-correction functions.

US Pat. No. 4,739,366 discloses a reproduction machine in which information regarding previous operations of the reproduction machine is stored in memory for subsequent retrieval and analysis in the event of a malfunction. There is. U.S. Patent No. 4,839,8
No. 22 discloses an expert system for indicating treatment for trauma. U.S. Patent No. 4,835,6
No. 90, a comprehensive expert system for medical image scanning, setup and scheduling is disclosed. A first expert system obtains index constraint values and priority values, and a second expert system optimizes these values.

US Pat. No. 4,740,885 discloses a computer control system for controlling a facility that utilizes knowledge engineering to select a mathematical model for facility control. U.S. Pat. No. 4,868,755 discloses an automatic control system for an aircraft, the first controller of which is connected to the operator's controller. The first controller is adapted to operate the flight control to reach a destination expressed in terms of selected aircraft parameters. The second controller provides a series of destinations to the first controller so that the aircraft performs the desired movements. The third controller acts as a mission planner and provides desired actions to the second controller according to the overall mission plan. The third controller is an expert system with expertise in flight planning and control.

Democrat and Chronicle, Rochester, New York, USA
d Chronicle) (April 18, 1988)
’s paper “Artificial intelligence has reached the PC” (Artificia
lIntelligence Reaching P
Cs) discloses the use of AI technology in personal computers. On page 61 of TIME magazine dated April 28, 1988, Xerox's RIC (Remo)
te Interactive Communicat
ions) (remote conversational communications). According to the paper, by using the theory of a special Xerox team of diagnostic technicians, the RIC reads data from the copier's internal instruments, senses when something is about to fail, and alerts repair personnel. The repair person can alert the customer that an impending outage can be avoided by taking appropriate measures. However, this RIC system is located external to the reproduction machine and is only diagnostic and not self-correcting.

[0016] Sanyo uses remote programming using the copying machine's IC card and editing function.
Fuji Xerox is equipping its Model 5030 copier with an IC card option that is limited to editing. Engineer Society of Detroit, USA
P. Liu of ing Society
), C. N. Lee and Ming-Lee Chiu's paper "
A Layered Intelligent Architecture for Programmable Controller Configurations”
e Architect for Program
mable Controller Configura
tions) (June 1987), pages 77-83, discloses a knowledge-based system architecture for configuring control systems for specific applications.

[0017] The expert system and control is 198
“1987 U.S. Control Council Bulletin” published in June 2007 (Pr.
oceedings of the 1987Amer
ican Control Conference). All patents and publications cited herein are hereby incorporated by reference.

[0018]

SUMMARY OF THE INVENTION It is an object of the invention to provide a machine that is intelligent and thus able to monitor its performance and adapt to changing conditions. Another object of the present invention is to be intelligent, so that it can communicate with the operator to better understand his or her objectives or requirements, and adapt to the operator to best meet those objectives or requirements. Our goal is to provide machinery. Yet another object of the invention is to provide a machine that can be predicted and thus avoid or minimize unscheduled maintenance and outages and provide the highest possible reliability. . Yet another object of the invention is to provide a machine that improves performance by allowing knowledge base updates.

[0019]

SUMMARY OF THE INVENTION To achieve the foregoing and other objects, and to overcome the drawbacks mentioned above, a machine having subsystems and components that perform a variety of functions is equipped with a diagnostic and control system. A real-time controller monitors and controls the machine and controls at least some of the subsystems according to set parameters. a first comprising information and rules containing the operation of said subsystems individually and collectively and representing the overall and selected operating areas of the machine;
The memory of the computer is used as a knowledge base, and this memory is supplied with information and rules about the machine by experts in the field. By using information acquired by sensors located within the machine and monitoring the operation of the machine, subsystems and components, and by using the information and rules in the first memory, the reasoning mechanism , determining and providing parameters to the real-time controller.

The diagnostic and control device is used to control an image production device, such as a copying machine or a printer, or some independent peripheral device to these devices, such as a document handling device or finishing device. A plurality of sensors are provided in the imaging device to enable an expert system to monitor the performance of a selected set or all of the subsystems and the overall performance of the machine or selected parts thereof. . The expert system then provides operating parameters to the real-time control system to adjust the operation of the machine, if necessary, for example to achieve the highest possible output image quality, jam-free operation, or Allows the operator to maintain other objectives. Additional actuators may also be provided within the imaging device, allowing the real-time control system to execute instructions from the expert system and perform adjustment operations previously requested by the technician. It is.

[0021] The on-board expert system can also interact with and work with external computer systems via the RIC board. This external computer system can access external expert systems to enhance overall diagnostic and correction capabilities. Although typical conventional image creation devices have real-time closed-loop control capabilities for many malfunctions, the present invention provides even more functionality by combining an expert system and a real-time control system. Provides the ability to close loops.

The present invention will be explained in detail below with reference to the drawings. In the figures, the same reference numerals indicate the same members.

[0023]

[Embodiment] The present invention will be described below with reference to an embodiment in which the present invention is applied to one type of copying apparatus. ), and also other types of devices, especially devices that include multiple components and systems that interact with each other to incrementally accomplish the device's main purpose. The present invention can also be used in printers that print images by receiving an electronic data stream from, for example, a computer. Printers are slightly different from copiers. That is, while a copying device typically produces an image that is an exact copy of the original (although it may differ in size and/or color), a printer can produce images that are, for example, an exact copy of the original, by changing the font in which the text is printed. Alternatively, an image can be created for the first time by splicing data together to "generate" an image. Therefore, "
The term "imaging device" refers to both copying devices and printers, and all other types of devices that form images on a recording medium, such as paper. The invention is also applicable to individual modules used with or as part of image production devices, such as document handling and finishing devices.

[0024] As used herein, the term "module" generally refers to a device that can stand alone. For example, a finishing device, an image input terminal, and an image scanner are considered modules because they can be used independently. The module is also referred to as a "subsystem" when used within an imaging device, such as a reproduction machine, since it is a subsystem of the device. Separately manufactured and sold devices, such as document handling devices, are also referred to as modules (although the document handling devices are not necessarily used independently) or subsystems of a larger device. Imaging devices have other subsystems that are not generally considered modules, such as sheet feeders, developer stations, and fusing stations. The device also has components that are typically discrete elements, such as solenoids, motors, and sensors. These components are not complex enough to be considered subsystems. That is, a typical device has, for example, at least one module (or subsystem) and may have additional components. The present invention is based on a single module (
(whether used independently or as a subsystem of a larger device) and may include one or more subsystems (which may be provided as modules) and may include additional It is applicable to large devices that may include components.

Next, the drawings will be explained. The drawings show one embodiment of the present invention, and the present invention is not limited thereto. FIG. 1 is a perspective view of a copying apparatus according to the present invention. The copying machine 10 includes a document handling device 12 for transporting documents to be copied to appropriate locations within a processing module 14, where the copying process takes place. Copy paper stock is passed from copy sheet holding trays 16 and 18 through copy sheet module 20 to processing module 14 for manipulation. The manipulated copy is then sent to finishing module 22;
In this module, processing steps such as collation, editing, stapling or bookbinding take place. Control panel 24 with display screen 26 includes
It allows the machine operator to start and stop the copying operation by selecting various options available within the device and otherwise program the machine operation, for example by inputting data and objectives. Display screen 26, along with control panel 24, allows the operator to view selected machine conditions and certain control conditions of the equipment.

FIG. 2 shows the general operational arrangement of a reproduction apparatus according to an embodiment of the invention. Module 14 is provided with a belt 30 having a photoconductive surface deposited on a conductive substrate. Belt 30 rotates about drive roller 32, tension roller 34, and strip roller 36. Successive sections of photoconductive belt 30 are advanced by the belt through processing stations that are arranged in sequence around the path of belt 30.

At the beginning of the copying process, a portion of belt 30 passes through charging station A. At this charging station, a corona generator (or coronode)
40 charges the surface of belt 30 to a relatively high uniform potential. After the surface of belt 30 is charged, this charged portion is passed through exposure station B. At exposure station B, the document to be copied is delivered onto a transparent platen 42 by a document handler 12 (which may include a recirculating document handler, for example). A lamp 44 illuminates the document. The light rays reflected from the illuminated document are transmitted through lens 46 to form the light image. Lens 46 focuses this light image onto the photoconductive surface of belt 30 and selectively dissipates the charge on that surface. An electrostatic latent image is recorded on the photoconductive surface corresponding to informational areas contained within the original document.

After the electrostatic latent image is recorded on the photoconductive surface of belt 30, the portion of the belt carrying this image is advanced to development station C. At developer station C, a magnetic brush developer 48 brings developer material into contact with the latent image on belt 30. For example, the magnetic brush type developing device 4
8 has magnetic brush type developing rollers 50 and 52. Each roller brings developer into contact with the latent image. rollers 50, 5
2 form a brush of carrier granules and toner particles extending outwardly from it. The latent image attracts this toner and forms a toner powder image on the latent image.

After development, the image bearing portion of belt 30 advances to transfer station D. Copy sheets, such as paper, transparencies, etc., are fed from copy sheet module 20. Transfer station D has a corona generator (or coronode) 54 that bombards the backside of the copy sheet with ions that attract toner particles from the photoconductive surface of belt 30. After toner transfer, the copy sheet is sent to fusing station E.

Fusing station E includes a fusing device assembly 60
to permanently fix the transferred toner powder onto the copy sheet. Fuser assembly 60 includes a heated fuser roller 62 and a backup roller 64. The copy sheet is passed between fuser roller 62 and backup roller 64 with the toner powder image on the copy sheet in contact with the fuser roller. In this manner, the toner powder image is permanently affixed to the copy sheet. After fusing, the copy sheet is routed to either output tray 66, finishing module 22 or screen copy tray 68 where additional operations are performed. Copying operations in the manner described above are well known and are not part of the present invention.

Although the method described above reflects light from a document directly onto photoconductive belt 30, the present invention can be used to image a document in a reproduction machine that uses other configurations (ie, to image the original document). A latent image can also be formed on the belt. For example, a raster input scanning device may be used to scan an image-containing side of a document to generate electronic data signals representing images contained on the document. This data signal can then be used to control (or modulate) the laser beam and direct the beam of light onto the photoconductive belt to form a latent image thereon. Some examples of reproduction devices using scanners and/or laser printers of the type mentioned above are described in U.S. Pat. No. 4,724,330;
No. 4,864,415, No. 4,903,079
No. 4,647,981. The contents thereof will be referred to and explained in this specification.

Alternatively, the data signal can be used to control the flow of ions toward an electron-receptive surface (eg, a belt or drum) to form a latent image thereon. Examples of reproduction devices that use a stream of ions to form a latent image on an electron-receptive surface include U.S. Pat.
No. 646,163, No. 4,524,371, No. 4
, No. 524,371, No. 4,463,363, No. 4,538,163, No. 4,644,373,
and No. 4,737,805. The disclosures of these patents are incorporated herein by reference. That is, the term "page" as used in these patent disclosures refers to an image actually printed on a page, or an electronic signal representing an actual printed image (scanning said electronic signal from a document, It can then be used immediately to form a latent image on the belt, or it can be stored in a memory, such as a floppy disk, and used later to form a latent image on the belt). Furthermore, images can be sent, for example from a computer, along with full page images or in combination with instructions for configuring a page.

In the present invention, a photoelectric or pressure sensitive sensor is placed at a predetermined location within a reproduction machine, such as along a document handling device paper path or copy sheet transport, or along a path of a photoconductive belt. do. For example, photoelectric sensors S1, S2, S3, S4, and S5 are placed along the paper path of the copy sheet transport device.
A selector gate located proximate the copy sheet tray conveyor 80 that transports the copy sheets outwardly from the copy sheet trays 16 and 18, a position on the conveyor that transports the copy sheets to the fuser 60, and a selector gate that transports the paper to the inverter 86 or output tray 66. 82, or at the output tray nip 88, or at the duplex tray output 90. More sensors of various types may also be used at various locations within the copying or imaging module or processing module 14, or within any other module.

The number and type of sensors used will depend on the cost and complexity desired in the reproduction device. For example, the following generic parameters are sensed. i.e., contamination (e.g., dirt on sensors and/or other components of the reproduction device), image density on the paper or photoreceptor (e.g., monitoring the operation of the reproduction device, machine subsystems, and/or components); air pressure, paper leading edge, paper thickness, paper curl, paper skew, toner flow rate, paper or mechanical element motion detection, resistivity, temperature, noise detection equipment (to detect impending subsystem or component failure), proximity detection, gas detection (such as detecting ozone), current detection, voltage detection, and toner belt detection. Some or all of these sensor types can be used to significantly improve reproduction machine performance and reliability. The location of these and additional sensors is determined by the reproduction device, subsystems, and components being monitored and controlled. This will be clear to those skilled in the art from the foregoing description.

FIGS. 3, 4 and 5 are block diagrams illustrating the components of the diagnostic and control system according to the present invention and their general interrelationship. The embodiment shown in FIG. 4 is similar to the embodiment of FIG. However, the embodiment of FIG. 4 is coupled to a remote computer system that can access the expert system via a RIC board (described below). The embodiment of FIG. 5 uses multiple expert systems (distributed expert systems), each of which is inherently attached to a different subsystem or module of the reproduction machine.

In general, the present invention combines several artificial intelligence techniques and techniques, particularly those involved in knowledge-based system development, as well as conventional control techniques. A knowledge-based control architecture consists of real-time control system elements as well as coupled knowledge bases and super-control/reasoning systems. The knowledge base includes an understanding of how the overall machine or selected segments thereof and the various control system elements operate, the mutual independence of the machine's elements and their influence on performance and behavior, and control. It consists of an operating window of parameters and associated corrective actions necessary to maintain said window, and alternative actions to maintain machine operation. Additionally, the knowledge base includes failure modes and their likely causes, ranges of values for parameters, and rules applied to these values to signal impending failure. The knowledge base can also be used by e.g. design engineers,
Consisting of rules based on heuristics derived from field engineers and others, this enables the machine to deal with problems of the type described above. A knowledge-based controller system that has knowledge of the overall machine as part of its knowledge base constantly monitors the behavior of the machine, detects any undesired behavior, and takes appropriate corrective action.

The architecture of the knowledge-based control system also facilitates easy changes to its knowledge base,
This improves the performance of the machine. This flexibility also provides the advantage that the knowledge base can be easily updated in the field from experience drawn from similar machines in use. This knowledge-based approach also allows each machine to be customized according to specific customer requirements. For example, if the knowledge machine is a copying machine, this knowledge-based method allows the machine to reconfigure its operation and performance based on specific customer requirements, such as forming images on a particular type of substrate. can be made as high as possible. For example, sensors S1 through S5 can be placed in the copy sheet feed path to determine the type of copy sheet being fed therethrough and automatically send signals to components of the reproduction machine. , adjust the operation of subsystems and other system elements (by changing the parameters that make them operate through a real-time control system) to achieve the highest possible output within a given speed range without jamming. Image quality can be provided. For example, the temperature and/or speed of the fixing device E, the voltage applied to the coronode 54, and deviations in paper handling (
The maximum speed at which the copy sheet feeding system can operate without excessive skew or damage is determined based on measurements taken by sensors S1 through S5 located within the copy sheet feed path, based on the copy sheet type and other Optimum control can be automatically performed depending on the characteristics (for example, thickness) of the material. Although it is conceivable that some of these functions may be controlled by traditional CLC methods, the diagnostic and correction capabilities can be expanded by using more knowledge and rules that traditional CLC methods cannot handle. .

The diagnostic and control system shown in FIG. 3 is generally applied to lower cost or less complex products than those to which the diagnostic and control system of FIG. 4 is applied. The diagnostic and control system of FIG.
) board, and the RIC board is coupled to a remote computer system. This remote computer system includes or is coupled to (and thus has access to) an expert system (remote expert system). This remote expert system performs functions beyond the capabilities of the onboard expert system, such as inferring that a machine will soon need repair and what the task of this repair is. It is equipped with the ability to notify the technician. The remote expert system can signal that repairs are needed that are beyond the adaptive control capabilities of the on-board expert system or beyond the on-board system's conversational capabilities with the customer to determine the problem. . The on-board expert system has some ability to infer many repair jobs and send this information via the RIC to an external computer system, but this is supplemented by a remote expert system. Furthermore, R.I.
The on-board expert system's interaction with an external computer via C allows information from the machine's field personnel to be fed into the on-board expert system to update its knowledge base.

The system shown in FIG. 4 is generally for more expensive products than that shown in FIG. Another embodiment using the expert system in a copier or printer is shown in FIG. This embodiment uses a distributed expert system. That is, a copying machine or printer is equipped with several expert systems, each of which has the primary function of diagnosing and deducing corrective actions for machine subsystems or subordinate functions or combinations thereof. vinegar. Each of the several expert systems is inherently connected to a subordinate element of the real-time control system of the overall machine. This dependent element is typically a real-time controller for a subsystem or dependent function. Although such a distributed expert system is inherently coupled to the real-time control functions of subsystems or subordinate functions, it is also connected to the total machine real-time controller, RIC (optional), as shown in FIG. ), and N
Connected to VM. Additionally, a total expert system may be provided to coordinate the operation and interaction of each of the distributed expert systems. By providing a distributed system, diagnostic and control devices can be equipped with modules or peripherals for image production devices, such as document handling devices, image scanners, or finishing devices. These can also be made as separate devices and these can be mixed and matched with the marking engine portion of the imaging device.

Application of the diagnosis and control system according to the present invention to the copying apparatus shown in FIGS. 1 and 2 will now be described. The output devices of a copying machine are devices such as motors, actuators, and solenoids, and these devices include:
For example, it performs functions such as controlling the speed of copy sheet and document transport systems, photoconductive belt 30, and finishing equipment 22. Additional output devices controlled in accordance with the present invention include components such as elements of an imaging system in which the original document and the intensity of light directed to the photoconductive belt 30 and charged by the coronode 40 are controlled in accordance with the present invention. The potential of photoconductive belt 30 that is applied is controlled based on the sensing conditions. Further, the potential at which the coronode 54 is charged and the temperature at which the thermal fixing device 60 is heated are also controlled.

Essentially all functions can be controlled at a certain cost and complexity level. Some of the controlled functions are illustrated below. That is, 1. Paper separation and delivery, paper transport, paper speed, timing and orientation, decurling pressure, and bending radius; 2. fusing pressure, temperature, roller speed, oil distribution speed, and roller torque; 3. Incremental photoreceptor speed, photoreceptor charge or voltage, photoreceptor tracking force, photoreceptor drive torque, photoreceptor toner image density, 4. Charge transfer and erasure corotron or scorotron voltage or current, charging element timing,5.
Cleaner roller or brush speed and penetration, cleaner vacuum pressure and flow rate, cleaner roller or brush bias, 6. Toner dispenser speed, toner supply level, toner consumption level, 7. Speed of the developing roller, bias of the developing roller, gap between the developing roller and the photoreceptor, 8. scanner or imager lamp intensity, digital imager intensity and timing; and 9.
The machine's ambient temperature, air flow and pressure characteristics are controlled.

Sensors such as sensors S1 to S5, and sensors commonly used to control the aforementioned components of a reproduction machine, provide information regarding the operation of these components to a real-time control system, which system The information provided by the sensor is used to, for example, issue commands to advance sheets, send fault signals, and control real-time operation of output devices based on set parameters and other machine control functions. do. Periodically collected information regarding the operation of components as detected by various sensors is also stored by the control system in non-volatile memory (NVM), such as a hard disk. Also, other information not directly used by the real-time control system is provided to the NVM and used by the expert system to send information through the RIC or by repair personnel. For example, sensor S
The arrival time of the leading edge of the paper as it arrives at copy sheet holding tray 16 can be determined from the time that the feed clutch in the paper feeder or copy sheet holding tray 16 is activated. Arrival time statistics (mean and standard deviation) can be stored to determine whether the performance of the feeder and vertical transport device or copy sheet conveyor 80 is deteriorating over time. Similarly, fuser roller torque information can be stored over time to assess roller wear or pressure fluctuations. These data are not used to change feeder or fuser settings, but are used to initiate warnings of impending repair operations or to change parameter settings in adjacent subsystems. This allows system performance to be re-optimized. Similarly, as stored in NVM,
There is other data such as ambient temperature, dirt and noise detection thresholds, paper, fuser oil and toner usage, and failure rates or impending failure detection thresholds.

The knowledge base is supplied with knowledge from experts in the field of imaging devices, such as engineers, designers, and technicians. This knowledge is stored as information, data, relationships, or rules, and represents the thought processes used by technicians in dealing with various problems that arise when performing maintenance on equipment. Expert systems monitor machine performance on the basis of information obtained from sensors and identify any problems that arise in the operation of the machine or in the operation of one or more subsystems or components of the machine.
Diagnosis is based on the information and rules contained in the knowledge base. After diagnosing the imager, the expert system sends control instructions to the real-time control system, which change the parameters by which the control system controls the imager's output device and, if possible, the imager's output device. to maintain the desired quality. The expert system can advise the equipment operator via the display 26 of any problems that are occurring or have already occurred. In this way, the operator of the imaging device can repair the device before it breaks down, thus improving the overall performance of the imaging device and improving the overall performance of the device during use. losses can be avoided or minimized. The expert system also examines and utilizes input from the customer for diagnostic or corrective purposes, or sends its inferences and other relevant information to the RIC. That is, the expert system means can interface with the operator either directly or via real-time control means.

The following examples illustrate some of the problems or situations that can be addressed by the present invention and how the present invention addresses these problems. however,
This is shown as an example, and the invention is not limited thereto. Components of paper jam image creation device (
Worn document and copy sheet feeding subsystems (particularly, including belts, motors, and gates) can reduce the drive force for documents or copy sheets, potentially delaying their arrival. Such late arrivals are detected as not having arrived at a certain point by the preset arrival time and result in a soft jam (i.e., the paper is not damaged but
This is often signaled by a signal indicating that the machine has stopped operating, causing trouble. While a conventional machine would continue to operate at the same preset arrival time, the present invention uses an expert system and knowledge base to infer increased subsystem wear (i.e., increase the arrival time). (by detecting overtime increases or by directly monitoring component wear, or both) and decreasing setpoints to indicate late arrival and increasing the speed of the paper drive member. Adapting the timing and control of the paper path by doing one or both of the following: These adjustments to preset times and to drive speeds
When the minimum and maximum values are reached, respectively, the machine can be operated properly and the repair work of the technician is directed by the expert system. This instruction may be done by instructing the customer to do so or by the RIC.

Another example of wear is manifested as increased paper skew, which can result in hard jams with paper damage. In the present invention, an expert system reduces the causes of uneven roller wear. Such effects would be computationally too long to analyze in a real-time control system, even if possible. By accessing occasional information, expert systems can perform this reasoning in parallel and economically. Expert systems work similarly in many other cases where evolutionary reasoning is required to deduce impending failure. The machine is more reliable to the customer since it continues to operate without paper jams and/or damage.

The diagnostic and control system of FIG. 4 is similar to that of FIG. However, the system of Figure 4 is equipped with a RIC board to enable the on-board expert system to communicate with, and potentially access, remote computer systems. Additionally, the RIC board allows the on-board expert system to indicate to a technician that the reproduction device requires repair, and the information it infers. Also, a RIC system external computer, with or without a remote expert system, can send instructions to the onboard expert system to correct the problem via appropriate instructions to the real-time control system.

The present invention has been described above with reference to embodiments thereof, but these embodiments are shown as examples, and the present invention is not limited thereto. Various modifications can be made without departing from the spirit and scope of the invention as set forth in the claims.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a copying apparatus according to the present invention.

FIG. 2 is a side view showing a paper path in the copying apparatus according to the invention.

FIG. 3 is a block diagram showing the operating members of the embodiment of the present invention.

FIG. 4 is a block diagram illustrating the operating elements of another embodiment of the invention that includes an on-board expert system capable of interacting with a remote computer system.

FIG. 5 is a block diagram illustrating the operating elements of a further embodiment of the invention in which distributed expert systems are provided for different subsystems or modules of a machine;

[Explanation of symbols]

A Charging station B Exposure station C Developing station D Transfer station E Fusing station

Claims (1)

[Claims] 1. In an image forming apparatus for forming an image on a recording medium, during an image forming operation, a transport device passes the recording medium through various subsystems and components on which the sheet operates. at least a first paper path and an on-board diagnostic and control system for testing operation of the imaging device and controlling the subsystems and components of the imaging device based on the testing. , said on-board diagnostic and control system is an expert system having real-time control means for monitoring and controlling said subsystems so that said subsystems can operate according to set parameters, and knowledge base and reasoning mechanism means. and the prior knowledge base has knowledge about the image creation device expressed as information, data and rules;
The reasoning mechanism means is for providing the set parameters to the real-time control means, and the reasoning mechanism means causes the real-time control means to adjust the subsystems and components according to information required by the knowledge base. An image creation device characterized in that the set parameters are determined by using information acquired when monitoring the image forming apparatus.