Monitoring system in auto-restoring image reproducing system

For an image reproducing system provided with an auto-restoration capability, a monitoring system is disclosed involving display by an image reproducing machine of the system in connection with fault diagnosis and auto-restoration processes by the image reproducing machine. The disclosed monitoring system in particular concerns a network of likewise auto-restoring image reproducing machines in communication with a host computer. The image reproducing machine has machine-condition constant-monitoring sensors through which a main controller of the image reproducing machine detects faults causing operational malfunction. A communication device transmits data indicating operational malfunction in an image reproducing machine from its main controller to the host computer. The main controller prepares and executes an auto-restoration process implementing restorative operations to compensate functionally for the detected faults, and interprets as restorative state data success of implemented restorative operations. A restoration process data storage of the image reproducing system stores data identifying an executed auto-restoration process. The restoration process data and the restorative state data are displayed by an image reproducing system display, which display can be by the host computer, as monitored at a remote service station by a service engineer.

BACKGROUND OF THE INVENTION 
1. Technical Field 
The present invention relates to image reproducing apparatuses provided 
with auto-restoration capabilities, and in particular relates to 
monitoring and display of auto-restoring functions in such image 
reproducing apparatuses. 
2. Description of Related Art 
Auto-restoration capabilities in image reproducing apparatuses such as 
photocopying machines, facsimile devices and page printers are known. 
Auto-restoration capabilities enable the image reproducing apparatuses to 
resume operations despite minor machine malfunctions. Auto-restoring image 
reproducing apparatuses, wherein normal machine performance has been 
impeded due to mechanical or like trouble, can automatically regain 
minimum requisite functions by executing various restorative operations. 
Machine operating conditions are constantly monitored in auto-restoring 
image reproducing apparatuses. When it is thus determined that there has 
been machine a malfunction, the type of fault is diagnosed. According to 
the fault diagnosis, the controller formulates a restoration plan which 
will fulfill functional operability of the device. The controller then 
directs the machine to execute restorative, usually compensatory, 
operations according to the restoration plan. After restorative operations 
have been finished, a machine operating panel displays the fact that 
recovery from a malfunction has been accomplished by auto-restoration. 
Functional operability does not mean complete restoration of the image 
reproducing apparatus to its normal operating condition prior to 
malfunction. Rather, functional operability is recovery, properly only 
temporary, of requisite machine functions following malfunction. Machine 
functions are recovered by restorative operations which, for example, 
compensate for a malfunctioning component. 
More specifically, in image reproducing apparatuses having this sort of 
auto-restoration capability, depending on the nature of the fault, there 
are instances in which machine operations are restored from a malfunction 
condition by controlling select components associated with the 
malfunctioning part to operate abnormally. 
If the developing roller in a photocopying machine, for example, does not 
conduct development bias satisfactorily, the result may be overly dark, 
faulty copy images. In this case, increasing above normal control 
threshold the amount by which the exposure unit exposes the photoconductor 
drum, and reducing below normal control threshold the voltage at which the 
main charger charges the photoconductor drum can serve to maintain machine 
functionality. Since operability is only restored temporarily in such 
cases, maintenance work, (replacing the developer unit, for example), must 
be carried out by a service engineer in order to enable the machine 
control functions to return to normal. 
Accordingly, with image reproducing apparatuses having an auto-restoring 
function as described above, the operating panel displays the fact that 
auto-restoration has enabled the machine to recover from a malfunction. 
Nevertheless, since functionality has been restored and the image 
reproducing apparatus appears on the surface to be operating normally, a 
photocopying machine user may neglect to contact a service engineer. 
Subsequently, in the event the same malfunction occurs again, the machine 
may not be able likewise to regain operability through its 
auto-restoration capability. 
A service engineer, when summoned, will carry out maintenance work on the 
machine making reference to a service manual. In the foregoing example, 
for instance, the service approach would be based on the observation that 
the copy images are too dark. However, the cause (i.e., the fact that 
there is a fault in the developer unit, rather than in the main charger or 
the exposure unit) would be neither clearly nor immediately 
understandable, encumbering the maintenance work and making restoration of 
the machine from its faulty condition more time-consuming than it might be 
otherwise. 
SUMMARY OF THE INVENTION 
The object of the present invention is to facilitate maintenance work in an 
image reproducing system provided with an auto-restoring capability. 
An image reproducing system provided with an auto-restoration capability 
according to the present invention includes an image reproducing machine; 
a main controller for executing image reproducing and auto-restoration 
functions of the image reproducing machine; a fault detecting means for 
detecting faults causing operational malfunction in the image reproducing 
machine; auto-restoration means for preparing and executing an 
auto-restoration process implementing restorative operations to compensate 
functionally for machine faults detected by the fault detecting means; a 
restoration process data storage means for storing restoration process 
data identifying an executed auto-restoration process; a restorative 
operation success-interpreting means for interpreting as restorative state 
data success of the restorative operations of an auto-restoration process; 
and a display output means for displaying restoration process data from 
the restoration process data storage means, and for displaying restorative 
state data from the restorative operation success-interpreting means. 
Furthermore, the image reproducing machine of an image reproducing system 
in accordance with the present invention is communicable with a host 
computer in a network with image reproducing machines likewise provided 
with an auto-restoration capability. Therein, the image reproducing system 
further includes a communication means for transmitting output from the 
display output means to a host computer via a transmission line. 
The image reproducing system in accordance with the invention further 
includes a machine-condition monitoring means for continually monitoring 
the condition of the image-reproducing machine. The fault detecting means 
detects faults causing operational malfunction in the image reproducing 
machine based on data from the machine-condition monitoring means. 
Furthermore, the machine-condition monitoring means can include the 
restorative operation success-interpreting means, such that following 
implementation of restorative operations by the auto-restoration means, 
the machine-condition monitoring means generates restorative state data 
indicating whether the restorative operations are successful. 
Moreover, in the image reproducing system in accordance with the present 
invention, the communication means is linked to the machine-condition 
monitoring means so as to transmit data from the machine-condition 
monitoring means to the host computer when the fault detecting means 
detects faults. 
In an image reproducing system according to the present invention, when the 
restorative operations of an auto-restoration process are implemented by 
the auto-restoration means, restoration process data identifying the 
executed auto-restoration process is stored in the restoration process 
data storage means. 
Then the restoration process data as well as the restorative state data 
interpreted by the restorative operation success-interpreting means, is 
displayed by the display output means. 
Herein, by examining the displayed data on restoration processes and 
interpreted restorative state data, a service engineer can pinpoint the 
cause of the fault(s) accurately and can repair the device easily even if 
a fault occurs after auto-restorative operations have restored the machine 
to functional operability. Thus maintenance work can be facilitated. 
In a network of auto-restoring capable image reproducing apparatuses which 
communicate with a host computer via communications lines, malfunction 
situations in the image reproducing apparatuses can be determined by the 
host computer. Accordingly, the fault(s) giving rise to the malfunction in 
an image reproducing apparatus in question can be recognized remotely. 
Maintenance work can then be carried out having prepared replacement 
components in advance, for example. This can further facilitate the 
maintenance work. 
Furthermore, in an image reproducing system in accordance with the present 
invention, since the image-reproducing machine is continually monitored, 
faults in the event of machine malfunction can be detected accurately. 
Moreover, in an image reproducing system in accordance with the present 
invention, when the fault-detecting means detects a fault based on data 
from the machine-condition monitoring means, a communications means 
communicates data from the machine-condition monitoring means to the host 
computer. Not only can the host computer indicate that a fault has been 
detected, but accordingly from the host computer the cause of the fault 
can be accurately grasped. This can yet further facilitate maintenance 
work. 
These and other objects, features, aspects and advantages of the present 
invention will become more fully apparent from the following detailed 
description of the present invention when taken in conjunction with the 
accompanying drawings, where like reference numerals denote corresponding 
parts throughout, in which:

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
As shown in FIG. 1, a photocopying machine management network includes 
several photocopying machines 2. The photocopying machines 2, according to 
one embodiment of the present invention, are connected to a host computer 
1 via telephone lines 3. It should be understood that instead of the 
telephone lines 3, transmission lines in a local area network (LAN), for 
example, could also serve as network lines. 
As shown in FIG. 2, the host computer 1 includes a CPU 4, to which are 
connected a RAM 5 and a ROM 6, and an input/output device 7. A display CRT 
8a, a printer 8b, an input keyboard 9 and an external storage device 10 
are connected to the CPU 4. The input/output device 7 is provided with a 
serial interface such as an RS232C. A network control unit (NCU 
hereinbelow) 7a is connected to the serial interface of the I/O device 7, 
and further is connected to the telephone line 3. 
As shown in FIG. 3, the photocopying machine 2 contains a centrally 
disposed photosensitive drum 20. A document glass 19 is provided above the 
photosensitive drum 20. A document D to be copied is placed on the 
document glass 19. An exposure unit 21 for document scanning is provided 
between the document glass 19 and the photosensitive drum 20. The exposure 
unit 21 includes a halogen lamp (HL) 22 as a light source, and a lens 
unit. A main charger (MC) 23, a developer unit (DU) 24 and a transfer unit 
25, among other components, are disposed around the periphery of the 
photosensitive drum 20. Further, a photosensor 30, which detects the 
quantity of light from the halogen lamp 22; a surface potential sensor 31, 
which detects the surface potential of the photosensitive drum 20; and a 
toner density sensor 32, which detects the density of toner adhered to the 
photosensitive drum 20, are disposed around the periphery of the 
photosensitive drum 20. 
A paper supply unit 35 is provided below the photo-sensitive drum 20. The 
paper supply unit 35 is provided with a paper supply cassette 36, a paper 
delivery assembly 37 which delivers paper from the paper supply cassette 
36, and a paper discharge device 38 which discharges paper onto which an 
image has been transferred. A fixing device 39 which fuse-fixes the toner 
image onto the paper is disposed downstream from the paper discharge 
device 38. 
The photocopying machine 2 is provided with a main control unit 50 as shown 
in FIG. 4. The main control unit 50 has a photocopying machine control 
unit 51 which controls the principal photocopying machine operations, a 
restoration executing unit 52 which executes auto-restoring operations, 
and a restoration planning unit 53 which formulates an auto-restoration 
plan. 
In the restoration executing unit 52, values from the various sensors are 
received via the photocopying machine control unit 51 and attributized, 
and are supplied thus to the restoration planning unit 53. In the 
restoration planning unit 53, based on the attributized sensor values, 
malfunction judgement, fault analysis and restoration plan are prepared. 
ROM 6 stores fault models based on predetermined acceptable values or 
ranges for parameters such as development bias, control threshold for 
exposure by the exposure unit, main charger charging voltage, toner 
quantity, and fixing unit fusing temperature, for example. The restoration 
planning unit 53 accomplishes fault analysis by comparing the attributized 
sensor values with the fault model parameters. Furthermore, the ROM 6 also 
stores function models, which specify requirements for the different 
photocopying machine functions. 
By correlation with the fault models, selections of necessary functions 
from among the function models are stored in the ROM 6 as well. These 
selections represent manifest requirements to maintain machine 
functionality in modeled fault situations. In preparing a restoration 
plan, the restoration planning unit analyzes what machine functions are 
necessary to restore the machine to operability by determining, based on 
the fault analysis, which manifest requirements are not satisfied. 
The restoration plan thus prepared is output to the restoration executing 
unit 52. The restoration executing unit 52 carries out restorative 
operations based on the supplied plan. 
An input key unit 55, located in an operating panel (not shown) and a 
display unit 56, as well as the surface potential sensor 31, the toner 
density sensor 32 and the photosensor 30, are connected to the main 
control unit 50. Further, an HL (halogen lamp) control unit 57, an MC 
(main charger) control unit 58, a DU (developer unit) control unit 59, a 
memory unit 60 and other input/output units are connected to the main 
control unit 50. The HL control unit 57 is connected to the halogen lamp 
22, the MC control unit 58 is connected to the main charger 23, and the DU 
control unit 59 is connected to the developer unit 24. Further, an NCU 61 
is connected to the main control unit 50. The NCU 61 contains a modem and 
is connected to the telephone line 3. It should be understood, however, 
that if an alternate communication line is used, the NCU 61 may include a 
communicating device other than a modem. 
In the restoration steps in the auto-restoration operations executed by the 
restoration executing unit 52, restoration triggering data which has 
become a restoration trigger, restoration process data, and restoration 
result data as to whether the restorative operation(s) have been a 
success, are stored in the memory unit 60. 
Following is a description of the operation of the embodiment as 
structurally detailed above. 
If the start of a copying operation has been commanded by manipulation of 
the input key unit 55, then the halogen lamp 22 of the exposure unit 21 is 
lighted, and image information is scanned from the document D placed on 
the document glass 19. Further, paper is supplied from the paper supply 
cassette 36 to the photosensitive drum 20. A toner image is formed on the 
photosensitive drum 20 in accordance with the scanned image information, 
and the toner image thus formed is transferred by the transfer unit 25 
onto the supplied paper. The paper discharge device 38 discharges the 
paper bearing the transferred toner image, meanwhile delivering it to the 
fixing device 39. In the fixing device 39, the toner image is fuse-fixed 
onto the paper, which is then discharged. 
Machine operations are controlled during the copying process in accordance 
with the control flow diagrammed in FIG. 5. Therein, step S1 of the 
control process determines whether the luminous energy irradiated by the 
exposure unit 21 is to be unusually large, depending on whether a luminous 
energy increase key, which is located in the input key unit 55, has been 
manipulated a number of times within a predetermined period. In step S2 a 
decision is made to determine whether a service engineer has been called 
due to whatever malfunction. In step S3 a decision is made to determine 
whether a sheet number trigger (a trigger which goes on with every 
prescribed number of copies) is on. If the result of any of these 
determinations is "yes" the control process shifts to step S4. In step S4 
the copying action is halted. Step S5 executes, by means of input from the 
surface potential sensor 31, the toner density sensor 32 and the 
photosensor 30, a self-diagnosis of the current condition of the 
photocopying machine. Step S6 determines whether the results of the 
diagnosis indicate that there is a malfunction in photocopying machine 
operability. If the determination in step S6 is that there is a 
malfunction, then the control process shifts from step S6 to step S7. In 
step S7 an auto-restoration process plan is prepared and accordingly 
restorative operation(s) are executed. 
In an instance in which the main controller is to direct an 
auto-restoration process, initially it derives candidate causes for the 
malfunction. Fault models are then selected by performing malfunction 
simulations based on the candidate malfunction causes. 
The controller then continues by preparing an auto-restoration plan. 
Therein, restoration objectives are determined. The restoration objectives 
are determined from requirements not satisfied among the manifest 
requirements for all necessary machine functions. The necessary machine 
functions in a given instance of malfunction are stored in the ROM 6, 
selected in advance from among the function models, by correlation with 
the fault models. One of the restoration objectives which have been 
determined is then selected. 
Candidate restorative operation(s) to meet the selected restoration 
objective are derived from parameters among the fault models and know-how 
on restorative operations. As a restoration model, the photocopying 
machine condition following execution of the selected candidate 
restorative operation(s) is then derived by a simulation technique. 
Restoration models for each restoration objective in turn are thus 
evaluated, and the candidate restorative operation(s) which fulfill the 
most restoration objectives and which also have the least amount of side 
effects are selected. 
The auto-restoration process is executed for the candidate restorative 
operation(s) which thus have been selected. 
In step S8, restoration process data identifying the auto-restoration 
process thus executed is stored. 
In step S9 it is determined whether the auto-restoration process has been 
completed. If there are a plurality of candidate restorative operations 
under the auto-restoration plan, the control process returns to step S7 
and the next restorative operation is executed. 
If it is determined that the auto-restoration process has been completed, 
the control process shifts to step S10. In step S10 it is determined 
whether the auto-restoration process was successful. 
The controller then directs the photocopying machine to carry out an 
auto-check or an auto-test run as needed to monitor the outcome of the 
auto-restoration process. The restored state resulting from the executed 
auto-restoration process as monitored by the various sensors is stored as 
restorative state data. 
Herein, the photocopying machine optionally may include machine restorative 
state sensors in communication with the main controller such that when the 
auto-restoration process has been completed, in step S10 the main 
controller interprets data from the machine restorative state sensors as 
restorative state data indicating whether the restorative operations are 
successful. In other words, the restorative operation success-interpreting 
means can be exclusive of the machine-condition monitoring means. 
Wherein the photocopying machine is provided with machine restorative state 
sensors, on the other hand these may be employed together with the 
constant-monitoring sensors in monitoring the restored state of the 
photocopying machine as restorative state data. 
In case the auto-restoration process was not successful, the control 
process then transfers to step S11. In step S11, the control values 
executed by the restoration plan are restored to their state when the 
malfunction occurred (the state during normal control of the photocopying 
machine). In step S12 the display unit 56 displays a message to the effect 
that restorative operation(s) by the auto-restoration process have failed. 
In step S13, the restorative results of the auto-restoration process, the 
information that the restorative operations have failed, and restoration 
trigger data (state monitoring data) indicating which of steps S1 through 
S3 determined that the restoration routine should be executed, are 
transmitted to the host computer 1 as fault data, and the control process 
ends. 
If, however, it is determined that the auto-restoration process was 
successful, then the control process shifts from step S10 to step S15. In 
step S15 the display unit 56 displays the fact that the auto-restoration 
process is finished. The auto-restoration process herein is the 
maintaining of machine functionality by executing restorative operations. 
That is, the procedure does not accomplish complete restoration. 
Photocopying machine functions are thereby only restored so as to maintain 
machine operability. In contrast, faulty parts are not repaired or 
replaced. 
In step S16, fault data is transmitted to the host computer 1, likewise as 
in step S13. In step S17, the copying operation is restarted. 
Meanwhile, the host computer 1 determines, in step P1 in the FIG. 6 
flow-chart, whether fault data has been received. In step P2 it is 
determined whether an output command has been made. If it is determined 
that fault data has been received, then the control process transfers from 
step P1 to step P3. In step P3 the received fault data is stored in the 
RAM 5. If it is determined that an output command has been made, then the 
control process shifts from step P2 to step P4. In step P4 the fault data 
recorded in the RAM 5 for each photocopying machine is listed out in 
display or printed. From the fault data output accordingly, a service 
engineer is able to comprehend the photocopying machine condition and 
carry out maintenance work on the photocopying machines. 
Herein, since it is judged from a remote location whether a faulty 
photocopying machine has been restored to operability by the 
auto-restoration capability, it is possible to grasp easily whether a 
photocopying machine in question is one in which functionality has been 
regained by auto-restoration. Further, by examining the fault data 
obtained via the host computer 1, it is possible to determine accurately 
the cause originating malfunction, meanwhile distinguishing photocopying 
machines whose functions have been regained by auto-restoration from 
otherwise faulty photocopying machines. This capability accordingly 
improves maintenance workability. 
The present invention may also be applied to image reproducing apparatuses 
other than photocopying machines, for example page printers or facsimile 
devices. 
In an image reproducing apparatus in accordance with the present invention, 
results interpreting the auto-restoration processes as well as the 
restoration condition are made available as display. Accordingly, a 
service engineer can recognize the cause of a malfunction accurately by 
examining the output results, and can repair the image reproducing 
apparatus readily even if a malfunction has occurred following restoration 
to functional operability by the machine's auto-restoration capability. 
This can facilitate the maintenance work. 
Further in accordance with the present invention, in a network of 
auto-restoring capable image reproducing apparatuses which communicate 
with a host computer, the state of image reproducing apparatuses which 
have malfunctioned can be determined by the host computer. Accordingly, 
the fault(s) giving rise to the malfunction in an image reproducing 
apparatus in question can be recognized remotely. Maintenance work can be 
then be carried out having prepared replacement components in advance. 
This can further facilitate the maintenance work. 
Moreover, in accordance with the present invention, image reproducing 
apparatuses having an auto-restoration capability are monitored 
constantly, such that fault detection can be performed accurately in the 
event of machine malfunction. In the network of the image reproducing 
apparatuses communicating with a host computer, the host computer 
accordingly can recognize that a fault has been detected. Thus the fault 
causing the malfunction can be recognized accurately, which can further 
facilitate subsequent maintenance work. 
Various details of the invention may be changed without departing from its 
spirit nor its scope. Furthermore, the foregoing description of the 
embodiments according to the present invention is provided for the purpose 
of illustration only, and not for the purpose of limiting the invention as 
defined by the appended claims and their equivalents.