JP2019215392A - Diagnosis system, image forming apparatus, diagnostic method, and program - Google Patents

Abstract

To provide a system, a method and the like that can efficiently perform diagnosis of abnormality in an image forming apparatus.SOLUTION: The system comprises: one or more detection means that detect the state of one or more parts in an image forming apparatus; setting means that sets up a condition for generating an image for diagnosis on the basis of results of detection performed by the one or more detection means; generation means that generates the image for diagnosis according to the set-up condition; reading means that reads the generated image for diagnosis; and diagnosis means that diagnoses abnormality in the image forming apparatus on the basis of the read image for diagnosis.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a system for diagnosing abnormality of an image forming apparatus, an image forming apparatus, a diagnosis method, and a program for causing a computer to execute the diagnosis.

  In an image forming apparatus such as a printer, an unintended image (abnormal image) such as background contamination or low image density may be formed due to deterioration over time or environmental fluctuation. When such an abnormal image occurs, a service technician selects and prints a test chart (test pattern), visually confirms the location of the abnormal image, investigates the cause, and replaces, adjusts, and cleans the part. Take action such as performing.

  In such a measure, the time during which the image forming apparatus cannot be used (downtime) is long, and there are many work items.

  Therefore, a technique has been proposed in which test patterns are switched according to the type of abnormal image in order to accurately acquire information necessary for failure diagnosis and efficiently perform maintenance work (for example, see Patent Document 1).

  In the above-described technology, the user needs to determine the type of the abnormal image. However, the abnormal image may have an easily-viewable image density that changes depending on the density fluctuation of the device or the type of the abnormal image. Sometimes the type cannot be determined.

  In this case, it is necessary to switch the test pattern, print again, read the test pattern, and perform the analysis, which takes a long time for diagnosis, and there is a problem that the diagnosis cannot be performed efficiently.

  The present invention has been made in view of the above problems, and has as its object to provide a system, a method, and the like that can efficiently diagnose an abnormality of an image forming apparatus.

In order to solve the above-described problems, in one embodiment of the present invention, there is provided a system for diagnosing an abnormality of an image forming apparatus,
One or more detection means for detecting a state of one or more parts in the image forming apparatus;
Setting means for setting conditions for generating a diagnostic image based on a detection result of the one or more detection means;
Generating means for generating a diagnostic image according to the conditions set by the setting means;
Reading means for reading the diagnostic image generated by the generating means,
A diagnosis unit that diagnoses an abnormality of the image forming apparatus based on the diagnostic image read by the reading unit.

  According to the present invention, it is possible to efficiently diagnose the abnormality of the image forming apparatus.

FIG. 1 is a diagram illustrating a configuration example of an image forming apparatus according to an embodiment. FIG. 2 is a block diagram illustrating a main configuration of the image forming apparatus. FIG. 2 illustrates an example of a functional configuration of the image forming apparatus. 5 is a flowchart illustrating a flow of an entire process of diagnosing an abnormality of the image forming apparatus. 5 is a flowchart illustrating a flow of processing for detecting an abnormality from image data of a test pattern. FIG. 7 is a diagram for explaining a transition of an operation screen. FIG. 7 is a diagram for explaining a transition of an operation screen. FIG. 7 is a diagram for explaining a transition of an operation screen. FIG. 7 is a diagram for explaining a transition of an operation screen. FIG. 4 is a diagram showing a first example of a test pattern for adjusting a color tone. The figure which showed the 2nd example of the test pattern which adjusts a hue. The figure which showed an example of the test pattern which detects unevenness. The figure which showed an example of the test pattern which detects one-color background stain and density. The figure which showed an example of the test pattern which detects the background dirt and density of all colors. FIG. 4 is a diagram for describing detection of a toner adhesion amount. FIG. 7 is a diagram illustrating a change in an output value of an optical sensor in a non-image portion. FIG. 4 is a diagram for explaining a change in an output value of an optical sensor in an image section. 9 is a flowchart illustrating an example of a process for determining a test pattern from an output value of an optical sensor in a non-image portion. 9 is a flowchart illustrating an example of a process for determining a test pattern from an output value of an optical sensor in an image unit. The figure which showed the 1st example of the table which matched the output value of each sensor, the test pattern to be used, and the coping method. The figure which showed the 2nd example of the table which matched the output value of each sensor, the test pattern to be used, and the coping method. FIG. 6 is a diagram illustrating a first example of a table in which a print number counter, the number of sheets after component replacement to be used, and a test pattern to be used are associated with each other. FIG. 9 is a diagram illustrating a second example of a table in which a print number counter, the number of sheets after component replacement to be used, and a test pattern to be used are associated with each other. FIG. 5 is a diagram for explaining a method for determining a charging condition for an image portion and a non-image portion. 9 is a flowchart illustrating a flow of a process for determining whether to print a cleaning failure detection pattern. FIG. 6 is a diagram for describing a cleaning failure detection pattern. 9 is a flowchart illustrating a flow of a process for calculating a remaining toner adhesion amount after transfer on the photosensitive drum. 9 is a flowchart illustrating a flow of a process for determining whether printing of a cleaning failure detection pattern is necessary.

  FIG. 1 is a diagram illustrating a configuration example of the image forming apparatus according to the present embodiment. The image forming apparatus may be any apparatus that can read an image and form an image. Examples of the image forming apparatus include a multifunction peripheral, a copier, and a facsimile machine having a plurality of functions such as a print function, a copy function, a facsimile function, and a scanner function. Hereinafter, a description will be given assuming that a multifunction peripheral is used as the image forming apparatus.

  The image forming apparatus includes an automatic document feeder (ADF) 10, an image reading unit 11, an image forming unit 12, a control unit, a paper feed tray 13, a paper discharge tray 14, and an operation unit 15. Is done. The automatic document feeder 10 automatically conveys the document to the image reading unit 11 to read the document. The image reading unit 11 has a light source and an image sensor that converts light reflected on the document into an electric signal, reads a document image, and outputs image data.

  The image forming section 12 includes a photosensitive drum 20, a charging device 21, a laser optical system 22, a developing device 23, an intermediate transfer belt 24, a primary transfer roller 25, a secondary transfer roller 26, and a fixing device 27. It is comprised including. In FIG. 1, only one photosensitive drum 20, one charging device 21, and one developing device 23 are shown. However, in the case of a color image forming apparatus capable of color printing, these are the same as the number of colors used in color printing. Parts can be provided.

  The photoreceptor drum 20 rotates in a certain direction, is charged by the charging device 21, and forms an electrostatic latent image on the surface by laser light emitted from the laser optical system 22. The developing device 23 has a developing roller, and attaches toner as a developer to the surface of the photosensitive drum 20 by the developing roller to form a toner image. The toner image is transferred to the intermediate transfer belt 24 by the primary transfer roller 25, and is transferred by the secondary transfer roller 26 to the paper transported from the paper feed tray 13 by the transport roller 28. The paper is stored not only in the paper feed tray 13 but also in the double-sided tray 16 and the paper feed bank 17 and is fed from the set tray. The paper is sent to the fixing device 27 after the toner image is transferred. The fixing device 27 has a fixing roller and a pressure roller, heat is applied by the fixing roller, and pressure is applied by the pressure roller to fix the toner image on the paper. The fixing device 27 discharges the paper on which the toner image has been fixed to the paper discharge tray 14.

  The image forming unit 12 includes various sensors, and includes optical sensors 30a to 30c, a potential sensor 31, a fixing thermopile 32, a temperature and humidity sensor 33, and a torque sensor 34 as sensors. The optical sensors 30a to 30c detect the amount of toner adhered on the photosensitive drum 20 or the intermediate transfer belt 24 based on the amount of reflected light on the toner. The potential sensor 31 detects a potential on the surface of the photosensitive drum 20. The fixing thermopile 32 detects the surface temperature of the fixing roller. The temperature / humidity sensor 33 detects the temperature / humidity inside the image forming apparatus. The torque sensor 34 measures the rotational torque of each roller such as the developing roller, the primary transfer roller 25, the secondary transfer roller 26, the fixing roller, and the transport roller 28.

  The control unit includes a controller 40, a ROM (Read Only Memory) 41, a RAM (Random Access Memory) 42, an interface I / O 43, a drive control unit 44, a sensor control unit 45, an HDD (Hard Disk Drive) And the like, a storage device control unit 47, and a communication control unit 48.

  The controller 40 controls the entire image forming apparatus, and executes image processing and the like on the image data output from the image reading unit 11. The ROM 41 stores a boot program, firmware, and the like, and the RAM 42 provides a working area for the controller 40. The interface I / O 43 connects the controller 40 to each control unit and the operation unit 15, and enables exchange of signals.

  The drive control unit 44 sends a control signal to a drive circuit that drives the laser optical system 22, the developing device 23, the intermediate transfer belt 24, and the like, and controls those drive circuits. The sensor control unit 45 processes a signal detected and output by each sensor. Specifically, the sensor control unit 45 obtains the amount of toner detected by the optical sensors 30a to 30c, that is, the ratio between the amount of toner attached to the toner image of the test pattern and the amount of toner attached to the background, and sets the ratio as a reference. The change in the image density is detected by comparing with the value, and the control value of the toner density sensor of each color is corrected.

  The storage device 46 stores image data, an OS (Operating System), application programs for operating the image reading unit 11 and the image forming unit 12, and the like. The storage controller 47 controls reading and writing of data and the like to and from the storage 46. The communication control unit 48 connects to a network such as the Internet or an intranet (registered trademark), and controls communication via the network.

  The operation unit 15 includes an input unit such as an input button for a user to input, and a display unit such as a display for displaying a processing status or the like to the user. The operation unit 15 can be, for example, an operation panel equipped with a touch panel.

  Although the configuration of the image forming apparatus is as shown in FIG. 1, the main configuration is shown in FIG. 2 as each block, and the processing performed by each block will be described. The image forming apparatus includes a scanner 50, an image memory 51, an IPU (image processing unit) 52, a plotter 53, and a controller 54.

  The scanner 50 reads a test chart (test pattern), which is one of the document images. The IPU 52 performs image processing on the test pattern read by the scanner 50. The plotter 53 prints the image data after the image processing by the IPU 52 to generate a printed matter.

  The controller 54 controls the entire apparatus, exchanges image data between blocks, connects to a server, a PC, or the like via a network, and transmits and receives image data, detection values of each sensor, and the like. The image memory 51 includes the RAM 42 and the storage device 46 shown in FIG. 1 and temporarily stores image data to be processed by each block, and permanently stores the image data for use at a later date.

  The image forming apparatus may cause deterioration of components such as the photosensitive drum 20, the charging device 21, the developing device 23, the intermediate transfer belt 24, and the fixing device 27 over time, environmental fluctuation, the type of paper to be used, and the mismatch of image forming conditions. An abnormal image may be formed on the formed image. The environmental change is a change in temperature, humidity, and the like inside the image forming apparatus. The mismatch of the image forming conditions means that the detection values of the sensors do not match the set values such as the toner density, charging potential, laser light amount, and fixing temperature. When an abnormal image is formed, it is necessary to identify an abnormal part and determine a countermeasure method in order to indicate that any part has an abnormality.

  Therefore, the image forming apparatus performs a process of diagnosing an abnormality of the image forming apparatus. FIG. 3 is a diagram illustrating an example of a functional configuration of the image forming apparatus. The image forming apparatus causes the controller 54 shown in FIG. 2 to execute a program, thereby causing the image forming apparatus to function as each functional unit. The image forming apparatus includes at least one or more detection units 60, a setting unit 61, a generation unit 62, a reading unit 63, and a diagnosis unit 64 as functional units. The image forming apparatus can include, as other functional units, a printing unit 65, an input receiving unit 66, an extracting unit 67, a notifying unit 68, and a storage unit 69. Here, a description will be given assuming that the image forming apparatus includes a diagnostic system including these units, but some units may be present in one or more other devices.

  The input receiving unit 66 automatically selects a test pattern, receives an automatic diagnosis for performing a diagnosis, selects confirmation of a previous diagnosis result, and receives designation of a test pattern from a user.

  When the input receiving unit 66 receives the selection of the automatic diagnosis, one or more detecting units 60 detect the amount of toner attached to the photosensitive drum 20, the surface potential of the photosensitive drum 20, the surface temperature of the fixing roller, and the like. Then, the setting unit 61 sets conditions for generating a test pattern as a diagnostic image based on the detection results of the one or more detection units 60. The generating unit 62 generates a test pattern according to the conditions set by the setting unit 61.

  When generating the test pattern, the generation unit 62 can generate a two-dimensional code from information such as identification information (for example, a machine number) for identifying the output device and output date and time as necessary.

  The printing unit 65 prints the test pattern generated or specified by the generating unit 62. When printing the test pattern, a two-dimensional code or the like can be printed together.

  The input accepting unit 66 can accept designation of one of a plurality of diagnostic conditions for detecting an abnormality in an image from a user. The diagnosis condition includes a diagnosis time, that is, a permissible time for diagnosis, and the permissible time is an upper limit time of a time required for the diagnosis. By selecting one of the detailed diagnosis mode and the simple diagnosis mode, the diagnosis time limit is set. 1 or the diagnosis time limit 2 can be selected. The permissible time corresponding to the detailed diagnosis mode is set to a diagnosis limit time 1, and the permissible time corresponding to the simple diagnosis mode is set to a diagnosis limit time 2, and these relations are set as diagnosis limit time 1> diagnosis limit time 2. You. By selecting the allowable time in this way, the diagnosis can be terminated when the allowable time is reached.

  The reading unit 63 reads the test pattern of the printed matter printed by the printing unit 65. The extracting unit 67 extracts abnormality information indicating the characteristic of the abnormality from the test pattern read by the reading unit 63.

  The diagnosis unit 64 diagnoses an abnormality of the image forming apparatus based on the extracted abnormality information. In this diagnosis, the cause of the failure, such as which part has a failure, is analyzed, and a coping method such as replacement, adjustment, and cleaning of the part is determined. The diagnosis unit 64 stores the diagnosis result including the analyzed cause of failure and the determined coping method in the storage unit 69.

  The notifying unit 68 notifies the user by displaying the diagnosis result on the operation unit 15 or the like. In addition to the notification to the user, the notification unit 68 also performs notification to the service center according to an instruction from the user. Further, when the input receiving unit 66 receives the selection of confirming the previous diagnosis result, the notification unit 68 notifies the user by displaying the previous diagnosis result on the operation unit 15 or the like.

  The storage unit 69 stores definition information defining conditions for generating a test pattern in accordance with the detection results of one or more detection units 60 described later, in addition to the above-described diagnosis results.

  With reference to FIG. 4, an overall process for diagnosing an abnormality of the image forming apparatus will be described. The input receiving means 66 receives the selection of the automatic diagnosis mode, and starts the process from step 400. In step 401, one or more detecting means 60 detects the amount of toner attached to the photosensitive drum 20 and the like. In step 402, the setting unit 61 sets conditions based on the detection result of the detection unit 60. Then, in step 403, the generation unit 62 generates a test pattern according to the conditions set by the setting unit 61.

  In step 404, the printing unit 65 prints the test pattern generated by the generating unit 62. The image forming apparatus can display the image on the operation unit 15 and prompt the user to set the printed matter of the test pattern as a document on the document table of the scanner 50 or the ADF 10. The user confirms the display, sets the document on the platen or the ADF 10, and instructs the reading of the test pattern. In step 405, the reading means 63 reads the test pattern, generates and outputs image data of the test pattern.

  In step 406, the extracting unit 67 extracts the abnormality information from the image data output from the reading unit 63. In step 407, it is determined whether or not the abnormality information has been extracted. If extracted, the process proceeds to step 408; otherwise, the process directly proceeds to step 412.

  In step 408, the diagnosis unit 64 analyzes the cause of the failure based on the extracted abnormality information and acquires the cause of the failure. In step 409, the diagnosing means 64 determines and acquires a coping method based on the acquired failure cause. The diagnosis unit 64 generates a diagnosis result from the acquired failure cause and the coping method in step 409, and stores the diagnosis result in the storage unit 69 in step 410.

  In step 411, the notification unit 68 notifies the diagnosis result from the image forming apparatus to the service center via the network. At this time, the notifying unit 68 can also notify by attaching the image data of the test pattern to the diagnosis result.

  In step 412, the notifying unit 68 notifies the user or the serviceman of the diagnosis result such as the presence / absence of the abnormal part, the cause of the failure, the coping method, etc. on the screen of the operation unit 15 or the like. At this time, the display for the user and the display for the service person can be switched as necessary. The display for the serviceman can include more detailed information than the display for the user. When there is no abnormal part, the notifying means 68 displays that no abnormality has been detected. Hereinafter, description will be given assuming that the user receives the notification and operates.

  The user receives the notification of the diagnosis result and selects a response. The measures include terminating the diagnosis, implementing a coping method, and selecting a test pattern for individual diagnosis when the cause of the abnormality is not specified.

  After displaying the diagnosis result or the like in step 412, it is determined in step 413 whether the cause is specified based on the diagnosis result. If the cause is specified, the process proceeds to step 414; otherwise, the process proceeds to step 415.

  In step 414, it is determined whether confirmation of the processing result has been selected. If it is selected, the procedure returns to step 401 to perform the diagnosis again. If not, the diagnosis is terminated in step 417. The diagnosis may be ended in response to the pressing of the end button.

  In step 415, the user is notified that the cause is not specified. The notification to the user can be made by displaying the fact on the operation unit 15 or the like. In step 416, it is determined whether a test pattern for individual diagnosis has been selected. If selected, the process returns to step 403 to generate the selected test pattern and perform the diagnosis again. On the other hand, if not selected, the process proceeds to step 417, and the diagnosis ends. Also in this case, the process may be terminated in response to the press of the end button.

  FIG. 5 is a flowchart showing a detailed flow of the abnormality information extraction processing executed by the extraction means 67 in step 406 of FIG. This processing starts from step 500, and in step 501, the direction in which the document is read from the image data is detected. This direction is detected as the direction in which the document is printed and the direction in which the document is placed on the document table or the ADF 10 based on the register mark pattern, characters, two-dimensional code, and the like printed in the test pattern. The register mark pattern is a pattern provided at four corners serving as a guide of the printing range.

  In step 502, the inclination (skew amount) of the document is detected from the image data. The skew amount can be detected from a register mark pattern or the like printed in the test pattern.

  In step 503, the extension amount of the document is detected from the image data. The amount of extension of the document can also be detected from the register mark pattern or the like printed in the test pattern.

  In step 504, the presence or absence of an abnormal part is detected from the image data. When an abnormal point is detected, the position where the abnormality has occurred is detected. The location of the abnormality may be determined by using only the image data. However, the orientation of the original is not always the same, the original may be tilted due to the ADF 10 being pulled in, and the temperature of the original may be higher. Taking into account expansion and contraction due to humidity and humidity, it can be detected using the orientation of the document detected in steps 501 to 503, the detected skew amount and the detected expansion amount. As a result, it is possible to improve the detection accuracy of the position where the abnormality has occurred.

  In step 505, the presence or absence of an abnormality is determined based on the presence or absence of an abnormal part. If it is determined that there is an abnormality, the process proceeds to step 506, and the shape and size of the abnormality existing in the position detected in step 504 are determined. To detect. The magnitude of the abnormality can be determined, for example, as a streak or a dot. In the case of a streak, it is determined whether the length or the end of the streak is sharp or blurred. If the end of the streak is sharp, it is an abnormality caused by an optical system such as writing or reading, and if the end of the streak is blurred, it can be estimated that the streak is caused by a cause other than the optical system. .

  In step 507, an abnormality that occurs in only one of the color plates of yellow (Y), magenta (M), cyan (C), and black (K), or an error that occurs in all the color plates of YMCK It is determined whether there is any abnormality or abnormality occurring in two or three color plates of YMCK. As a result, whether the color is a single color or a mixed color is determined, and the location of the abnormality is an abnormality occurring before the primary transfer (transfer of the toner from the photosensitive drum 20 to the intermediate transfer belt 24) or an abnormality occurring after the primary transfer. Can be determined. In other words, it can be determined before primary transfer for a single color, and after primary transfer for a mixed color.

  In step 508, it is detected whether an abnormality has occurred periodically. The abnormalities that occur periodically are abnormalities that occur due to rotating components (rotating members) such as the photosensitive drum 20, the developing roller, the primary transfer roller 25, and the secondary transfer roller 26. Since the period differs depending on the rotating members, Based on the cycle of the abnormalities that occur, it is possible to estimate which of the rotating bodies is abnormal.

  For example, the cycle can be detected with high accuracy even if a complex shape abnormality is calculated by calculating an autocorrelation function and using the calculated autocorrelation function. The autocorrelation function is a function used to calculate the period when an image has a repetitive component. The autocorrelation function is a well-known function and will not be described in detail here.

  The use of the autocorrelation function increases the amount of calculation and takes time. For this reason, it is desirable that the input receiving unit 66 be used when the calculation time is allowed, such as when the detailed diagnosis mode is selected as the specification of the diagnosis condition.

  On the other hand, when the calculation time is not permitted, for example, when the simple diagnosis mode is selected, a rectangle is obtained according to the size of the abnormal part instead of the autocorrelation function to reduce the amount of calculation, and the average value is obtained. Then, the period can be calculated. In addition, the period may be calculated for a complex shape abnormality using an autocorrelation function with a lower resolution than in the detailed diagnosis mode. The resolution reduction converts, for example, image data of 600 dpi into 300 dpi lower than 600 dpi.

  In the detailed diagnosis mode, the abnormality information is extracted with a wider range of parameters, smaller value steps, or a wider range of parameter and value steps smaller than the simple diagnosis mode. The parameter is a range of characteristic values representing the characteristics of the document, such as a range of the amount of elongation of the document. The step is a value representing a unit for performing the extraction, and may be, for example, a value of a period detection interval.

  Specifically, when the range of the amount of elongation in the simple diagnosis mode is ± 1% in the cycle detection, the range of the amount of elongation in the detailed diagnosis mode is wider than this range, for example, a range of ± 5%. Can be. In this example, the range is ± 5%, but is not limited to this.

  Further, when the cycle detection in the simple diagnosis mode is calculated at an interval of ± 2 mm with respect to 60 mm, the calculation can be performed at an interval smaller than this interval, for example, at an interval of ± 1 mm in the detailed diagnosis mode. Further, in the cycle detection, the skew angle to be detected can be made larger. This is to increase the detection accuracy of the position where the abnormality has occurred.

  In the simple diagnostic mode, the permissible time is short, so that the cycle of the rotating body is detected only for a deviation within the tolerance of the rotating body. Can be detected. The tolerance is a difference between a maximum value and a minimum value of an allowable error, and indicates an allowable range.

  In step 509, the density and the center of gravity of the abnormal group are detected. This makes it possible to detect whether the error occurs uniformly on the entire surface, in a group, or in isolation.

  When it is determined in step 505 that there is no abnormality, or after detecting the density and the center of gravity in step 509, the process proceeds to step 510, where the detection result is used as the test pattern abnormality information, and the process of extracting the abnormality information in step 511 ends. I do.

  When the simple diagnosis mode is selected and the diagnosis in the simple diagnosis mode is completed, and the allowable time has not been reached, the automatic transition to the detailed diagnosis mode is performed within the allowable time, and the diagnosis is performed in the detailed diagnosis mode. May go. The automatic transition can be performed by the diagnosis unit 64 designating the detailed diagnosis mode. This automatic transition makes it possible to detect an abnormality for which a diagnosis result cannot be obtained in the simple diagnosis mode. Note that the automatic transition can also be performed in the simple diagnosis mode even when a diagnosis result cannot be obtained.

  The processing executed by the image forming apparatus is as described above. The screen of the operation unit 15 for displaying to the user and accepting the user's input will be described with reference to FIGS. 6 to 9. .

  FIG. 6A is a diagram showing a screen selected by a user when a trouble occurs. This screen includes items for troubleshooting and maintenance. The troubleshooting includes “when printing cannot be performed as desired” as an item selectable by the user, and the maintenance includes “periodic inspection and cleaning method” as an item selectable by the user. The user or the like can select an item to be checked or an item to be checked, and the item can be selected by pressing a button on which the item is displayed.

  When the user selects “when printing cannot be performed as desired” in the troubleshooting, the screen transitions to a screen illustrated in FIG. This screen includes two selectable items: “when printing cannot be performed neatly” and “when paper and originals are jammed”. The user can select any item according to the trouble that has occurred.

  When the user selects "when printing cannot be performed neatly" on the screen of FIG. 6B, the screen changes to the screen shown in FIG. 6C. This screen includes the order of tasks of checking the type of trouble, coping method, and checking the effect, and the contents of the current task. The content of the current work is to select the type of trouble, and the items “automatic selection”, the type of individual trouble, and “end” to end the check can be selected. The types of individual troubles include "streak-like dirt", "white stripes / white spots", "dirt", "light image", and "shift / color shift". A small image is displayed in association with the type of the trouble in detail. When selecting the type of individual trouble, the user can select the type of the trouble according to which of the small images is closer.

  When the button on which the "periodical inspection and cleaning method" of the maintenance shown in FIG. 6A is displayed is pressed and the item is selected, the screen transits to the screen shown in FIG. 6D. This screen includes the sequence of operations such as periodic inspection, cleaning method, and effect confirmation, and the contents of the current operation. The contents of the current work include confirmation of an image and confirmation of a toner, and the flow of each confirmation work is shown. The user can proceed with the confirmation work by selecting the first item of the confirmation work, in this example, the item “select test pattern”.

  When the user selects “automatic selection” on the screen of FIG. 6C or “select test pattern” on the screen of FIG. 6D, the screen changes to a screen illustrated in FIG. 7A.

  The screen in FIG. 7A has a button of “start automatic selection”, and the user can press the button to start automatic selection. When the automatic selection is started, a transition is made to the screen shown in FIG. The screen shown in FIG. 7A has a plurality of check items such as background stain, image density, density unevenness (color shading), hue, and color misregistration. You can choose. In the case of individual selection, when the user selects a specific item and presses a “print start” button, a corresponding test pattern is selected, and the confirmation of the image displayed on the screen of FIG. From "Select test pattern" to "Print test pattern" and start printing the test pattern.

  A screen indicating that the test pattern is being automatically selected is superimposed on the screen of FIG. 7B. When the automatic selection is completed, the screen changes to a screen shown in FIG. In the screen of FIG. 7C, “automatic selection” and a confirmation item other than one confirmation item are in a state where selection is impossible (grayed out). When the user presses a “print start” button in that state, printing of the automatically selected test pattern starts.

  When printing is started, the screen changes to a screen shown in FIG. The screen shown in FIG. 8A is a screen that prompts the user to set the test pattern on a platen or the like in order to read the printed test pattern. The user can set the printed matter on a platen or the like in accordance with the instructions on the screen, and press the “start reading” button on the screen.

  The reading is started, and when the reading is completed, the screen transits to the screen in FIG. The screen in FIG. 8B is a screen showing the reading result. The read result is information such as a result indicating that there is no abnormality, and the type and position of the abnormality when there is an abnormality. In the example shown in FIG. 8B, "dirt" is detected as an abnormality, and the position is indicated by a small image. In addition, the screen of FIG. 8B is provided with a button “Display coping method”. The user can press that button to deal with the dirt.

  When an instruction to display a coping method is received, the screen transits to a screen illustrated in FIG. The screen in FIG. 8C is a screen for explaining a method for dealing with dirt. In the coping method, parts and the like are specified, and the contents of necessary work such as replacement and cleaning are indicated. It also shows the procedures for replacement and cleaning. The screen of FIG. 8C is provided with a button of “confirmation of effect”. By pressing the button, the user can re-diagnose and confirm the effect after the countermeasure, that is, whether or not the dirt is removed.

  When the “confirm effect” button is pressed, the screen changes to a screen illustrated in FIG. The screen of FIG. 9A is provided with a “print start” button and a “read start” button for printing the test pattern again and reading it for confirming the effect. The user presses a “print start” button to start printing the test pattern, sets a printed material on a document table or the like, and then presses a “read start” button to start reading the test pattern.

  When the reading of the test pattern is completed, the screen changes to a screen shown in FIG. On the screen of FIG. 9B, if the above measures have eliminated the abnormality, a message indicating that no abnormality is detected is displayed, and if not, information such as the type and position of the abnormality is displayed. The screen in the case where it has not been resolved is the same as the screen in FIG.

  The screen of FIG. 9B is provided with a button of “display next confirmation item” and a button of “end”. When there is an item to be confirmed, the user can press the “display next confirmation item” button to display the screen of FIG. 7A. As a result, it is possible to select another item, print and read the corresponding test pattern, and detect an abnormality.

  Each test pattern corresponding to the confirmation item selected on the screen of FIG. 7A will be described with reference to FIGS. FIG. 10 is a diagram showing an example of a test pattern for adjusting a color tone. This test pattern is composed of gradation patterns of all colors (yellow, magenta, cyan, black). The gradation pattern 70 is a pattern in which the gradation is changed every fixed value, such as 16 values, 32 values,... The area where the toner is not intentionally attached, that is, the non-image portion (background portion) 71 having no image has a value of 0.

  By using such a gradation pattern 70, it is easy to detect a deviation from a target gradation, and it is possible to read by the scanner 50 and adjust image processing parameters. As shown in FIG. 10, the tone pattern 70 may be provided with two sets of a photograph pattern and a character pattern, or may be provided with only one set such as a character pattern alone.

  In addition to the pattern, characters indicating a machine number, output date and time, a two-dimensional code, a message, and the like can be provided in the test pattern. The message may be of any content, but may include precautions when reading printed matter. As a cautionary note, as shown in FIG. 10, "set the sheet face down and set the arrow so as to match the left side of the copying machine" can be cited as an example.

  FIG. 11 is a diagram showing another example of the test pattern for adjusting the color tone. In the example shown in FIG. 10, only the primary colors (primary colors) of yellow, magenta, cyan, and black are used, but in this example, a color (secondary color) created by mixing the primary colors in addition to the primary colors And a gradation pattern 73 of a color (tertiary color) formed by mixing a primary color and a secondary color. The secondary colors are blue, green, and red, and the tertiary color is, for example, gray.

  By using such a pattern, it is easy to detect a deviation from the target tint, and it is possible to read the image with the scanner 50 and adjust the image processing parameters. When printing a test pattern, an image subjected to gradation processing by dither processing for copying or dither processing for a printer is printed in accordance with the image processing parameters used by the user. The dither processing is processing for realizing more colors with a limited number of colors by combining colors.

  FIG. 12 is a diagram showing an example of a test pattern for detecting unevenness of one specific color. Since the color is one specific color, the color may be yellow, magenta, cyan, or black. The test pattern is a pattern 74 formed with uniform write values on the entire surface. In other words, the test pattern has a constant density of 64 values, 128 values, or the like with respect to 8-bit 256 values. The pattern of each color of yellow, magenta, cyan, and black may be printed for each sheet of paper, or the area of each color may be divided, and the pattern of each color may be printed on each sheet of paper. In addition, printing may be performed by overlapping colors without being divided into regions.

  By using the pattern 74 formed with such uniform write values, it becomes easier to detect unevenness representing uneven write values. In this example, in addition to the pattern, a machine number, an output date and time, and a message are provided.

  In FIG. 12, a region (hatched portion) indicated by oblique lines on which the pattern 74 is formed indicates an image portion, and a non-hatched region indicates a non-image portion 71.

  FIG. 13 is a diagram showing an example of a test pattern for detecting a specific one-color background stain and image density. This test pattern is a pattern for detecting a specific one-color background stain and light / dark density. For an 8-bit 256 value, the image portion 75 has 256 values, the non-image portion 71 has 0 value, etc. This is a uniform density test pattern. The image part 75 and the non-image part 71 are not limited to 256 values and 0 values, but may be 200 values, 8 to 16 values, or the like in order to evaluate the margin. Since this is an example, other values such as 220 values and 20 values may be used.

  In the example shown in FIG. 13, it is easy to detect whether the background density and the image density are reduced by reducing the area of the image area 75, and two background stains 76 are formed in a wide area of the non-image area 71. Existing. The area where the image portion 75 is formed is not limited to the upper side as viewed in the drawing, as shown in FIG. 13, but may be the lower side, the left side, the right side, or the like.

  FIG. 14 is a diagram showing an example of a test pattern for detecting background smear and image density of all colors. The test pattern is a pattern for detecting background dirt of all colors of yellow, magenta, cyan, and black, and light / dark density. As in the example shown in FIG. The portion 77 is a uniform density test pattern having 256 values and the non-image portion 71 having 0 value or the like. The difference from the example shown in FIG. 13 is that the pattern of the image portion 77 is not one color but all colors.

  Also in this example, the image portion 77 and the non-image portion 71 are not limited to 256 values and 0 values, but may be 200 values, 8 to 16 values, or the like in order to evaluate the margin. Since this is also an example, other values such as 220 values and 20 values may be used.

  Further, it is possible to reduce the area of the image portion and to easily detect whether the background stain and the image density are reduced. In this example, the image portions 77 are formed at four places at the four corners and at the center. However, as in the example shown in FIG. The image portion 77 may be formed on the lower side, the left side, the right side, and the like. A register mark pattern can be provided in the test patterns shown in FIGS. 10 to 14 in order to detect the orientation, inclination, and the like of the document.

  Next, individual processes performed when “automatic selection” of a test pattern is selected will be described. First, a process for detecting the amount of toner adhesion will be described with reference to FIG.

  On the photoconductor drum 20, toner is discharged from the developing device 23 to form an image. Optical sensors 80a to 80c are provided to detect the amount of toner adhesion. The optical sensors 80a to 80c are opposed to the surface of the photosensitive drum 20 and are spaced apart so as to detect the amount of toner near both ends and near the center in the longitudinal direction perpendicular to the rotation direction of the photosensitive drum 20. Can be

  Each of the optical sensors 80a to 80c irradiates light and receives reflected light, and the amount of toner in an area (image portion) 81 to which toner is intentionally attached at each position and an area (non-toner) where toner is not attached. (The image portion) 82 is detected.

  The non-image portion 82 is a region where toner does not adhere. However, if toner adheres for some reason and the amount increases, a problem such as background stain occurs. The image portion 81 adheres a predetermined amount of toner. However, if the amount is smaller than the estimated amount for some reason, a problem such as a low image density occurs. Each of the optical sensors 80a to 80c detects a toner adhesion amount in the image portion 81 and the non-image portion 82 in order to detect the occurrence of such a problem.

  FIG. 16 is a diagram showing a change in output values of the optical sensors 80a to 80c in the non-image portion 82. The vertical axis of FIG. 16 indicates the output value of the optical sensor of the non-image portion 82, and the horizontal axis indicates the position of the photosensitive drum 20 in the rotation direction or the number of printed sheets. Note that when the horizontal axis is the position in the rotation direction, the graph shows the variation in the unevenness of one image, and when the horizontal axis is the number of prints, it is a graph showing the degree of deterioration due to temporal variation. The life can be predicted based on the tendency of the degree of deterioration.

  In order to determine the presence or absence of background stain, a background stain safety level and a background stain alert level are set as thresholds. Since the output value of the optical sensors 80a to 80c becomes higher as the amount of toner adhered is smaller, if the output value is higher than the background soil relieving level, it indicates that the amount of toner adhering to the photosensitive drum 20 is smaller. It can be determined that dirt hardly occurs.

  On the other hand, the output value of the optical sensors 80a to 80c decreases as the amount of toner adhered increases. Therefore, if the output value is lower than the background contamination alert level, it is determined that the background contamination has already occurred or is likely to occur. can do.

  The background dirt relief level and the background dirt alert level can be set to appropriate values by performing tests or the like. It should be noted that the background dirt relief level and the background alert level are not separately provided, but set as one level. Or a state that is likely to occur.

  As in the example shown in FIG. 16, when the background contamination safety level and the background contamination warning level are separately provided, there is a problem in that there is an output value between the background contamination security level and the background contamination warning level. In this case, it can be determined that the background stain is likely to occur.

  Output values are obtained from the optical sensors 80a to 80c at fixed time intervals or continuously, and the output values are substantially constant unless toner adheres and there is no background stain. However, when a partial background stain (unevenness) occurs, the output value varies depending on the position in the rotation direction and the number of prints. For this reason, when the fluctuation width is larger than the predetermined range, it can be determined that unevenness or the like is likely to occur.

  In FIG. 16, an example in which the presence / absence of the background stain is determined from the change in the output value has been described. With reference to FIG. 17, an example in which it is determined from the change in the output value whether the image density has become lighter will be described.

  FIG. 17 is a diagram illustrating a change in output values of the optical sensors 80a to 80c in the image unit 81. The vertical axis in FIG. 17 indicates the output value of the optical sensor of the image unit 81, and the horizontal axis indicates the position in the rotation direction of the photosensitive drum 20 or the number of printed sheets. When the horizontal axis is the position in the rotation direction, the graph shows the variation of the unevenness of one image, and when the horizontal axis is the number of printed sheets, it is a graph showing the degree of deterioration due to the temporal variation. The life can be predicted from the tendency of the degree of deterioration.

  In order to determine whether or not the image density is low, a low density security level and a low density alert level are set as thresholds. If the toner adheres sufficiently, the output values of the optical sensors 80a to 80c become low. Therefore, if the output value is lower than the safe level at which the density is low, the amount of the toner adhered on the photosensitive drum 20 is sufficient. It can be determined that a problem in which the density is low is unlikely to occur.

  On the other hand, when the amount of adhered toner decreases, the output values of the optical sensors 80a to 80c increase. Therefore, when the output value is higher than the low-level warning level, a problem that the density is already low or the density is low occurs. It can be determined that the state is easy.

  The light concentration security level and the light concentration alert level can also be set to appropriate values by conducting tests and the like. It should be noted that the low-density security level and the low-density alert level are not separately provided, but are set as one level. If the level is higher than this level, it is unlikely to occur. Or it may be determined that the state is likely to occur.

  As in the example shown in FIG. 17, when the low-density security level and the low-density alert level are separately provided, there is a problem in that there is an output value between the low-density security level and the low-density alert level. In this case, it can be determined that the density is easily reduced.

  Further, when the variation range of the output values of the optical sensors 80a to 80c is larger than a predetermined range, it can be determined that unevenness such that the image density is partially reduced easily occurs. .

  Based on the above, referring to FIG. 18, the process of determining a test pattern from the output values of the optical sensors 80a to 80c in the non-image portion 82 will be described with reference to FIG. Processing for determining a test pattern from output values will be described.

  If it is determined that background dirt is to be investigated, the process starts from step 1800 in FIG. 18, and in step 1801, the output values of the optical sensors 80a to 80c in the non-image portion 82 are all colors (yellow, magenta, cyan, and black). It is determined whether the level exceeds the background dirt security level (whether the level is higher than the security level). If it is higher than the background soil security level, the process proceeds to step 1802. If even one color has a background soil safety level or less, the process proceeds to step 1803.

  In step 1802, the output of the test pattern for detecting the background stain is omitted because the background stain is higher than the relief level, and the process proceeds to step 1808 and ends.

  In step 1803, it is determined whether the output values of the optical sensors 80a to 80c in the non-image portion 82 include any one of the colors that is less than the background dirt alert level (lower than the alert level). If any of the background dirt alert levels are lower than the background dirt alert level, the process proceeds to step 1804;

  In step 1804, the tint and the background stain are detected, and the density of the pattern at the time of outputting a test pattern for adjustment is determined. It is necessary to detect and adjust the hue, because when the level is lower than the background dirt level, the tint may be different. After the determination, in Step 1805, the color tone and the background stain are detected and a test pattern for adjustment is output, and in Step 1808, this processing ends.

  In step 1806, since at least one color is between the background dirt security level and the background dirt warning level and the other colors are higher than the background dirt security level, there is almost no difference in tint. A stain is detected, and the density of the pattern at the time of outputting a test pattern for adjustment is determined. After the determination, in step 1807, a background dirt is detected and a test pattern for adjustment is output, and in step 1808, this processing ends.

  If it is determined that the image density is to be checked, the process starts from step 1900 in FIG. 19, and in step 1901, the output values of the optical sensors 80a to 80c in the image section 81 are lower than the relief level where the density is low for all colors (reliable) Lower than the level). If the security level is lower than the light security level, the process proceeds to step 1902. If even one color has a security level higher than the light security level, the process proceeds to step 1903.

  In step 1902, since the density is lower than the low security level and the toner adhesion amount is sufficient, the output of the test pattern for detecting the image density is omitted, the process proceeds to step 1910, and the process ends.

  In step 1903, it is determined whether any of the output values of the optical sensors 80a to 80c in the image unit 81 exceeds the alert level with a low density (higher than the alert level) even for one color. The process proceeds to step 1904 if any of the alert levels are lower than the low alert level, and proceeds to step 1905 if the alert level is lower than the low alert level.

  In step 1904, a test pattern of all colors for detecting and adjusting the hue is output. Then, this processing is ended in a step 1910.

  In step 1905, since at least one color is between the low-density security level and the low-density security level, and the other colors are lower than the low-density security level, the image density of the corresponding color between them is detected. And outputs a test pattern for adjustment.

  Then, in step 1906, it is determined whether the fluctuation range of the output values of the optical sensors 80a to 80c in the image unit 81 is larger or smaller depending on whether or not it exceeds a predetermined range. If it is larger, proceed to step 1908; if smaller, proceed to step 1907.

  In step 1908, since a large variation width means that density unevenness has occurred in the image, a test pattern for detecting density unevenness of the corresponding color is output. Then, this processing is ended in a step 1910.

  In step 1907, it is determined whether or not the fluctuation range of the output values of the optical sensors 80 a to 80 c in the non-image portion 82 is large. As with the variation width of the output value in the image section 81, a predetermined range is provided, and the magnitude of the variation width can be determined based on whether or not the variation is within the predetermined range. If it is larger, the process proceeds to step 1908 to output a test pattern for detecting density unevenness of the corresponding color.

  On the other hand, if it is small, it means that the fluctuation width is small in both the image portion 81 and the non-image portion 82, and the process proceeds to step 1909, and the output of the test pattern for detecting the density unevenness of the corresponding color is omitted. .

  As described above, the test pattern can be determined from the output value of the optical sensor. However, at what level what kind of failure is expected to occur, how to deal with it, FIG. 20 is a table summarizing which test pattern should be used at which level in the sensor.

  FIG. 20 shows the detection target, the detection level, the fluctuation of the detection level, the defect of the image predicted to occur, the test pattern to be used, and the detection target for each of the optical sensor, the potential sensor, the temperature and humidity sensor, the fixing thermopile, and the torque sensor. FIG. 9 is a diagram showing an example of a table in which an example of a coping method is associated with an example of a coping method. There are four test patterns to be used: a background stain detection pattern, an image density detection pattern, a density unevenness detection pattern, and a tint detection pattern.

  In the column of the test pattern to be used, “○ (unnecessary)” indicates that the output of the corresponding test pattern can be determined to be unnecessary, and “× (necessary)” indicates that the output of the corresponding test pattern is required. Indicates that the item is deemed necessary.

  The potential sensor 31 is a sensor that measures the surface potential on the photosensitive drum 20. In writing using a laser or an LED, a negative latent image method is employed. Therefore, if the residual potential of the image portion (exposure portion) 81 increases due to deterioration of the photosensitive drum 20, the image density decreases. In this case, the charged potential is reduced, and the background image stain is likely to occur in the non-image portion (non-exposed portion) 82. In both the image section 81 and the non-image section 82, the sensor output on the photosensitive drum 20 fluctuates greatly and becomes uneven on transfer paper as a medium.

  Therefore, according to the output value of the potential sensor 31, a test pattern for image density unevenness, background contamination, density reduction, and the like is output.

  The temperature / humidity sensor 33 is a sensor that detects the temperature / humidity in the image forming apparatus. In the office environment, the room temperature is adjusted to around 25 ° C by air conditioning. However, the image forming apparatus is installed near the window during the time when air conditioning is in operation, such as early morning in winter, or even during the day when air conditioning is in operation. In this case, the temperature becomes close to the outside temperature (for example, a low temperature of 10 ° C. or less). In this case, the charge of the toner increases, and the image density tends to decrease.

  Even when the air conditioner is not operating, such as in the early morning of summer, or even during the day when the air conditioner is operating, if the image forming apparatus is installed near the window, the condition is close to the outside temperature (for example, a high temperature of 30 ° C. or higher). become. When the temperature is high and the humidity is high, the charge of the toner decreases, and the image density tends to increase.

  From these facts, a test pattern for confirming the image density and color is output according to the output value of the temperature / humidity sensor 33.

  The fixing thermopile 32 detects the temperature of the fixing roller. When the temperature of the fixing roller (fixing temperature) is reduced, a decrease in image density due to defective fixing of the toner, background contamination, and the like are likely to occur. The temperature fluctuation at this time may cause fixing unevenness, and may cause gloss unevenness and density unevenness.

  From this, a test pattern for confirming a decrease in image density and background contamination and a test pattern for detecting the occurrence of unevenness and color are output in accordance with the output value of the fixing thermopile 32.

  The torque sensor 34 detects a rotation state of a developing roller, a transfer roller, a fixing roller, a transport roller, and the like. Each roller may be stained, and the density of the image may be uneven due to wear of each roller. Therefore, a test pattern for detecting occurrence of unevenness is output according to the output value of the torque sensor 34.

  FIG. 21 is a diagram showing an example of a table in which a detection unit, a test pattern to be used, a candidate for a cause of failure, and a candidate for a coping method are associated with each other when an optical sensor and a toner density sensor are used as sensors. FIG. 21 is a more specific example of the example shown in FIG.

  The detecting means includes a sensor as the detecting means 60, a detection target detected by the sensor, a detection level, and a change in the detection level. The defects of the image that are predicted to occur include items such as none, background stain, density unevenness, color difference, poor character reproduction, low image density, and high image density.

  The test patterns used include a test pattern for detecting background dirt, a test pattern for detecting image density, a test pattern for detecting unevenness, and a test pattern for detecting hue. In this example, a test pattern for detecting the presence or absence of a character reproduction defect and a test pattern for detecting a character are further included.

  An error diffusion process is applied to a test pattern for detecting a character, and a dither process is applied to a test pattern for detecting a hue.

  Candidates of the causes of the failure include items such as deterioration of the photosensitive drum, deterioration of the developer, poor charging of the toner, environmental factors in the apparatus (temperature and humidity are high and low), and toner supply failure.

  Possible countermeasures include adjustment / cleaning, replacement of the developer, replacement of the photosensitive drum, replacement of the toner supply part, and the like.

  In the test pattern for detecting unevenness, the density at the time of output and the gradation processing to be applied vary depending on the detection target, the detection level of the sensor, the fluctuation range of the detection level, and the defect of the image whose occurrence is predicted. In this table, image density and gradation processing are associated. This makes it possible to select image density and gradation processing candidates in accordance with a detection target, a detection level, a fluctuation in the detection level, and a predicted image defect. For this reason, this table is stored in the storage unit 69 and can be used when the setting unit 61 sets image density and gradation processing as conditions.

  Processing that actually uses the table shown in FIG. 21 will be described. As a first example, a case where an optical sensor is used as the detection means 60, the detection target is the toner adhesion amount of the non-image portion 82 on the photosensitive drum 20, and the detection level is high (H2) and the fluctuation of the detection level is large Will be described.

  Referring to the table of FIG. 21, in the first example, it is predicted that background defects, uneven density, and different colors are generated as defects of an image whose occurrence is predicted. In order to detect this predicted defect, a test pattern for detecting background dirt, a test pattern for detecting unevenness, and a test pattern for detecting color are used. In the case of a test pattern for detecting unevenness, when the amount of toner adhering to the non-image portion 82 is large, the density of an image is usually easily reduced.

  As a second example, a case where an optical sensor is used as the detection unit 60, the detection target is the toner adhesion amount of the image portion 81 on the photosensitive drum 20, and the detection level is low (L2) and the fluctuation of the detection level is small explain.

  Referring to the table of FIG. 21, in the second example, it is predicted that, as a defect of the image whose occurrence is predicted, a difference in color and a low image density are generated. In order to detect the predicted defect, a test pattern for detecting the density and a test pattern for detecting the color are used.

  Here, when the phenomena of the first example and the phenomenon of the second example occur simultaneously, all of the test patterns used in the first example and the second example can be printed. In this case, the number of prints increases, and the handling of the test pattern becomes troublesome for the user. Therefore, the test pattern for detecting the unevenness and the test pattern for detecting the background stain are preferentially printed. This is because a test pattern for detecting unevenness is one of the causes of the occurrence of a difference in color, a low image density, or a high image density, which must be dealt with with priority.

  As a third example, a case where an optical sensor is used as the detection unit 60, the detection target is the toner adhesion amount of the image portion 81 on the photosensitive drum 20, and the detection level is low (L2) and the fluctuation of the detection level is large explain.

  Referring to the table of FIG. 21, in the third example, it is predicted that, as defects of an image whose occurrence is predicted, background stain, density unevenness, color difference, and low image density occur. In order to detect the predicted defect, a test pattern for detecting density, a test pattern for detecting unevenness, and a test pattern for detecting color are used. If the amount of toner adhered to the image portion 81 is low, a condition is set so as to use a test pattern for detecting unevenness with a high image density in order to easily detect the problem.

  Here, when the phenomena of the first and third examples occur simultaneously, all of the test patterns used in the first and third examples can be set and printed. In this case, the number of prints increases, and the handling of the test pattern becomes troublesome for the user. Therefore, the test pattern for detecting the background stain and the test pattern for detecting the unevenness are preferentially printed.

  As the test pattern for detecting unevenness, two types of a pattern having a low image density and a pattern having a high image density are set and printed. When two types are printed, the number of prints increases. Therefore, a pattern having a low image density can be replaced with a test pattern for detecting background dirt, and only a pattern having a high image density can be printed.

  As another method, it is possible to predict the cause of the problem in which the phenomena of the first and third examples occur at the same time due to the deterioration of the developer and the charging failure of the toner. Then, a test pattern for detecting background dirt and a test pattern for detecting unevenness in image density are printed.

  In the examples so far, the test pattern to be used is changed and the coping method is changed according to the detection level or the like, but the present invention is not limited to this. This is because the trouble also depends on the number of prints after component replacement and the like, and if the number of prints increases, the trouble is likely to occur.

  FIG. 22 is a diagram showing an example of a table in which the number of printed sheets counter after component replacement, a defect of an image whose occurrence is predicted, a test pattern to be used, and a coping method are associated. “○ (unnecessary)” in the column of test pattern to be used indicates that the output of the corresponding test pattern can be determined to be unnecessary, and “× (necessary)” indicates the output of the corresponding test pattern. Indicates that the item is deemed necessary.

  In the table of FIG. 22, the output of all test patterns is “× (required)” immediately after component replacement, because set failure, initial failure, and initial adjustment are required.

  In this case, a unit for counting the number of printed sheets is required, so that the image forming apparatus can include a counting unit such as a counter for counting the number of printed sheets.

  FIG. 23 is a diagram illustrating an example of a test pattern output when each of the types of trouble displayed on the screen of the operation unit 15 is selected by the user. When "automatic selection" is selected, the print density of the test pattern for detecting the density unevenness is automatically adjusted based on the output value of the optical sensor and the like. Even when “dirt” is selected, the print density of the test pattern for detecting density unevenness is automatically adjusted based on the output value of the optical sensor and the like.

  When "streak-like stain" is selected, the print density of the test pattern for detecting the density unevenness is automatically adjusted to be thin based on the output value of the optical sensor and the like. When “white stripes / white spots” is selected, the print density of the test pattern for detecting the density unevenness is automatically adjusted to a higher density based on the output value of the optical sensor and the like.

  In the automatic adjustment, when it is detected that the toner adhesion amount is larger than the reference of the output value of the optical sensor, the print density is adjusted to be lower than the reference. On the other hand, when it is detected that the toner adhesion amount is smaller than the reference of the output value of the optical sensor, the print density is adjusted to be higher than the reference. The setting unit 61 can set whether to make it lighter or darker as a condition. This is the same for the following adjustments.

  With respect to stains such as black streaks, a print pattern having a low print density and a uniform density is easier to detect than a test pattern having a high print density.

  On the other hand, with respect to stains such as white stripes, a print pattern with a high print density and a uniform density is easier to detect than a test pattern with a low print density, so the print density is adjusted to a higher density.

  When the output value of the optical sensor or the potential sensor 31 is between the safe level and the alert level, the test pattern can be printed and output on paper based on the table in FIG. 21. Conditions may be changed. This change can be made by the setting means 61.

  For example, the condition can be changed to a condition in which a background stain or a problem that the density becomes thin easily occurs. Specifically, as shown in FIG. 24, an arbitrary position of the sheet is set as the switching position, and the set value of the charging condition of the image unit 81 and the non-image unit 82 can be changed at the switching position. As a result, it is possible to detect how much trouble is likely to occur by reading with the scanner 50.

  Even if the condition is likely to cause a failure, if the failure does not occur, there is a margin for the occurrence of the failure, and it can be determined that the necessity of maintenance (component replacement or the like) is low. On the other hand, when the condition is set such that a problem easily occurs, when the problem occurs, it is possible to determine that there is no margin for occurrence of the problem and the necessity of maintenance is high. In this case, it is possible to take prompt action such as obtaining parts.

  Next, as an example of selecting “automatic selection”, determining whether or not to print a test pattern, and performing printing and diagnosing, as an example of determining whether or not to print a test pattern for detecting a cleaning failure, a process of diagnosing and diagnosing is performed. This will be described with reference to FIG. When the image forming apparatus is turned on by a user, the image forming apparatus forms a test pattern on the photosensitive drum 20 and the intermediate transfer belt 24 as one of a state check in the image forming apparatus and one of image forming condition adjusting operations, The amount of transfer residual toner on the photosensitive drum 20 is calculated. Further, the amount of toner adhesion is calculated while the user instructs printing and the image forming apparatus is performing a printing operation, at the end of printing, and the like.

  Therefore, this processing is started from step 2500 when the power of the image forming apparatus is turned on or during a printing operation. In step 2501, it is determined whether to calculate the amount of toner remaining after transfer on the photosensitive drum 20. Whether or not to calculate can be determined based on whether the image forming condition adjustment operation is being performed or whether the calculated condition is satisfied. The determination condition may include whether the printing operation has been completed, whether a predetermined number of sheets (for example, 50 sheets) have been printed during continuous printing, and the like.

  If not calculated in step 2501, the process proceeds to step 2514, and the process ends. When the calculation is performed, the process proceeds to step 2502, and the transfer residual toner adhesion amount on the photosensitive drum 20 is calculated. Then, in step 2503, it is determined whether or not it is necessary to print the cleaning failure detection pattern based on the calculated transfer residual toner adhesion amount. After the determination, in step 2504, the determination result is stored in the storage unit 69. The determination result includes, in addition to the necessity of printing, a result of necessity of printing of the test pattern determined based on FIGS. 20 to 22.

  In step 2505, "automatic selection" is selected, and the execution of the automatic diagnosis mode is accepted. Then, in step 2506, the stored judgment result is read. In step 2507, a test pattern to be printed is determined based on the read determination result. If the number of test patterns to be printed is too large, it takes a long processing time. For this reason, the priorities of the test patterns to be printed are determined, and the test patterns are printed in descending order of priority so that a phenomenon in which an abnormality in an image is likely to become apparent can be preferentially confirmed.

  In step 2508, it is determined whether printing of the determined test pattern is necessary. If it is determined that printing of the test pattern is unnecessary, the process advances to step 2513 to notify the user that printing is unnecessary. Then, the process ends in step 2514. After the notification, the printing of the test pattern may be continued according to the user's instruction.

  On the other hand, if printing is necessary, the flow advances to step 2409 to print a test pattern. FIG. 26 shows an example of a detection pattern for detecting a cleaning failure. The cleaning failure is a phenomenon in which the toner remaining on the photosensitive drum 20 after cleaning is removed. When the cleaning operation is good, the amount of residual toner is small, and therefore, the toner is evenly distributed on a blank sheet such as the non-image portion 83 where toner is not intentionally attached, or in a direction perpendicular to the sheet conveyance direction (main scanning direction). A test pattern with a low density of the image portion 84 attached is used.

  Specifically, when the toner has a value of 0 to 255 depending on the amount of toner attached, the non-image portion 83 to which no toner is attached has a value of 0, and the image portion 84 to which toner is most attached has a value of 255. The test pattern having a low density can be a light gray having a value of, for example, 16 to 32.

  The width W of the image portion 84 in the main scanning direction is the main scanning width excluding the margins at both ends, and the length L of the image portion 84 in the sub-scanning direction, which is the paper conveyance direction, is one round of the photosensitive drum 20. It can be about 1.1 times the length. The margin can be, for example, about 5 mm. The image section 84 can be a pattern of uniform write values without gradation processing, and a pattern in which gradation processing such as error diffusion or dither processing is performed on uniform image data values. There may be.

  Referring to FIG. 25 again, in step 2510, the printed material is placed on a document table or the like by the user, and a reading instruction is received. In step 2511, a test pattern is read. Then, in step 2512, diagnosis of the image forming apparatus is performed, and in step 2414, the process ends.

  FIG. 27 is a flowchart showing the flow of the process for calculating the transfer residual toner adhesion amount on the photosensitive drum 20 executed in step 2502 of FIG. This processing starts from step 2700. In step 2701, a test pattern is generated on the photosensitive drum 20, and development is performed to attach toner. In step 2702, the amount of toner adhering on the photosensitive drum 20 after development is detected.

  In step 2703, the test pattern on the photosensitive drum 20 is transferred to the intermediate transfer belt. In step 2704, the amount of toner attached on the intermediate transfer belt is detected.

  In step 2705, the amount of toner remaining on the photoconductor drum 20 after the transfer from the photoconductor drum 20 to the intermediate transfer belt is calculated from the toner adhesion amounts detected in steps 2702 and 2704 as the transfer residual toner adhesion amount. . In step 2706, the calculated transfer residual toner adhesion amount is stored in the storage unit 69.

  The amount of toner adhesion is detected at regular time intervals or continuously by an optical sensor, and the amount of toner remaining after transfer is calculated. In step 2707, the integrated value of the transfer residual toner adhesion amount on the photosensitive drum 20 is calculated. Then, in step 2708, the latest integrated value of the remaining transfer toner on the photosensitive drum 20 calculated is stored in the nonvolatile memory, and the process ends in step 2709.

  FIG. 28 is a flowchart showing a flow of processing for determining whether or not to print a cleaning failure detection pattern, which is performed in step 2503 of FIG. The process is started from step 2800, and in step 2801, the latest transfer residual toner adhesion amount on the photosensitive drum 20 stored in step 2707 of FIG. ,get.

  In step 2802, it is determined whether or not the transfer residual toner adhesion amount on the photosensitive drum 20 is smaller than the alert threshold. If it is smaller than the alert threshold, the process proceeds to step 2803, and if it is not less than the alert threshold, the process proceeds to step 2805.

  In step 2803, the latest integrated value of the transfer residual toner on the photosensitive drum 20 stored in step 2708 in FIG. In step 2804, it is determined whether or not the integrated value of the transfer residual toner on the photosensitive drum 20 is smaller than the alert threshold. If it is smaller than the alert threshold, the process proceeds to step 2806, and if it is not less than the alert threshold, the process proceeds to step 2805.

  In step 2805, at least one of the transfer residual toner adhesion amount and the integrated value thereof is equal to or higher than the alert threshold value, indicating that cleaning has not been sufficiently performed. On the other hand, in step 2806, it is determined that the printing of the cleaning failure detection pattern is unnecessary. Then, in step 2807, this determination processing ends.

  As described above, the state of one or more parts in the image forming apparatus is detected, the type of test pattern to be output from the state, and the density of the test pattern is printed. By judging whether or not it is necessary, useless printing can be suppressed, and abnormality of the image forming apparatus can be diagnosed efficiently. Since there is no need to print useless test patterns, the use of toner and paper can be suppressed, and the diagnosis time can be reduced. As a result, the burden on general users and service personnel can be reduced.

  Furthermore, since the state of one or more parts is detected, an appropriate test pattern is printed, read, and diagnosed, it is possible to cope with a sudden change in the use environment of the image forming apparatus.

  The present invention has been described with the above-described embodiments as a diagnostic system, an image forming apparatus, a diagnostic method, and a program. However, the present invention is not limited to the above-described embodiment, and can be modified in other embodiments, additions, changes, deletions, and the like within a range that can be conceived by those skilled in the art. . In addition, any aspect is within the scope of the present invention as long as the functions and effects of the present invention are exhibited.

  Therefore, it is also possible to provide a recording medium on which the above-described program is recorded, a program providing device which stores the above-mentioned program, and provides the program in response to a download request.

  Further, the diagnosis process does not need to be completed only in the image forming apparatus, and can be performed in cooperation with, for example, a server device or the like as an external device. In this case, the data collected by the image forming apparatus can be sent to the server apparatus, and the diagnostic result can be returned from the server apparatus to the image forming apparatus. Therefore, the diagnostic system can be configured as a diagnostic system that performs diagnostic processing, and can be implemented in the image forming apparatus, the server apparatus, or both. The external device is not limited to the server device, but may be another image forming device or the like and may be connected to one or more networks.

10 ... ADF
DESCRIPTION OF SYMBOLS 11 ... Image reading part 12 ... Image forming part 13 ... Paper supply tray 14 ... Discharge tray 15 ... Operation part 16 ... Double-sided tray 17 ... Paper supply bank 20 ... Photoconductor drum 21 ... Charging device 22 ... Laser optical system 23 ... Development Device 24 Intermediate transfer belt 25 Primary transfer roller 26 Secondary transfer roller 27 Fixing devices 30a to 30c Optical sensor 31 Potential sensor 32 Fixing thermopile 33 Temperature and humidity sensor 34 Torque sensor 40 Controller 41 ROM
42 ... RAM
43 ... Interface I / O
44 drive control unit 45 sensor control unit 46 storage device 47 storage device control unit 48 communication control unit 50 scanner 51 image memory 52 IPU
53 ... plotter 54 ... controller 60 ... detecting means 61 ... setting means 62 ... generating means 63 ... reading means 64 ... diagnostic means 65 ... printing means 66 ... input receiving means 67 ... extracting means 68 ... notifying means 69 ... storage means 70 ... floor Tone pattern 71 Non-image part 72 Color pattern 73 Tone pattern 74 Pattern 75 Image part 76 Background dirt 77 Image parts 80a to 80c Optical sensor 81 Image part 82 Non-image part 83 Non-image Section 84: Image section

Japanese Patent No. 4710495

Claims (10)

A system for diagnosing an abnormality of an image forming apparatus,
One or more detection means for detecting a state of one or more parts in the image forming apparatus;
Setting means for setting conditions for generating a diagnostic image based on a detection result of the one or more detection means;
Generating means for generating the diagnostic image according to the condition set by the setting means;
Reading means for reading the diagnostic image generated by the generating means,
A diagnostic unit for diagnosing an abnormality of the image forming apparatus based on the diagnostic image read by the reading unit.   2. The diagnostic system according to claim 1, further comprising storage means for storing definition information defining conditions for generating a diagnostic image in accordance with a detection result of each detection means.   The diagnostic system according to claim 1, wherein the setting unit sets the condition based on a detection value as the detection result and a variation range of the detection value.   4. The diagnostic system according to claim 1, wherein the setting unit sets, as the condition, a density of the diagnostic image, a type of gradation processing on the diagnostic image, or both. 5. . The one or more detection units include: a unit that detects a state of developer attached to an image carrier provided in the image forming apparatus; a unit that detects a charged state of the image carrier; and an environmental state in the image forming apparatus. The image forming apparatus includes at least one of a unit for detecting a temperature and a humidity, a unit for detecting a fixing temperature as a fixing state of a fixing device provided in the image forming apparatus, and a unit for detecting a rotation state of a rotating body including the image carrier.
The generation unit includes a pattern for detecting a phenomenon that the developer is attached to an area where the developer is not attached, a pattern for detecting the density of an image, and a pattern for detecting the density of an image color. The diagnostic system according to any one of claims 1 to 4, wherein the diagnostic system generates at least one of patterns for detecting a tint. Including an input receiving means for receiving a selection of the type of the abnormality,
The diagnostic system according to claim 1, wherein the generating unit generates the diagnostic image according to a type of the abnormality received by the input receiving unit. The image forming apparatus includes a counting unit that counts the number of images formed and output on a medium,
The diagnostic system according to claim 1, wherein the generating unit generates the diagnostic image in accordance with the number of outputs counted by the counting unit.   An image forming apparatus including the diagnostic system according to claim 1 and configured to form an image. A method for diagnosing an abnormality of an image forming apparatus, comprising:
Detecting a state of one or more parts in the image forming apparatus;
Setting a condition for generating a diagnostic image based on the detection result;
Generating the image for diagnosis according to the set conditions;
Reading the generated diagnostic image,
Diagnosing an abnormality of the image forming apparatus based on the read diagnostic image.   A program for causing a computer to execute each step included in the diagnostic method according to claim 9.