JP2011209764A - Image forming apparatus and remote central control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a photoreceptor from breaking down.SOLUTION: The image forming apparatus having a contact type bias applying means for applying bias to the photoreceptor, in contact with the photoreceptor includes: a detection means to detect a voltage value or a current value supplied to the contact type bias applying means; and a failure detection means to compare an output value from the detection means with a threshold so as to detect abnormal rotation of the photoreceptor based on a contrast rate. The threshold is variable.

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a multifunction machine using electrophotographic technology, and a remote centralized management system.

  2. Description of the Related Art Generally, an electrophotographic apparatus that can repeatedly form an image by sequentially performing a plurality of processes such as charging, exposure, development, transfer, and cleaning while the rotating photoconductor makes a round is generally used. In this electrophotographic apparatus, the charging, developing, and transferring processes among the above-described processes are processes for applying a bias to the photoconductor from a power pack as a power supply device. If a voltage or current exceeding the range is applied to the photoconductor, a part or a plurality of parts of the apparatus may be destroyed. Therefore, in order to prevent such destruction, a detection mechanism for detecting the output (voltage or current) of the power pack is provided, and when the output value of this detection mechanism reaches a certain threshold, the output of the power pack is stopped. The control method is taken.

  In Patent Document 1, the controller monitors each feedback voltage output from each feedback circuit of the high voltage unit, and controls each high voltage output from the charging output circuit, transfer output circuit, and development output circuit of the high voltage unit. At the same time, it is determined whether or not each of the feedback voltages is within a predetermined range. If there is a feedback voltage that is not within the predetermined range, it is determined that there is an abnormality and the corresponding high voltage is stopped. An electrophotographic image forming apparatus for notifying an operator of the abnormality is described.

  In Patent Document 2, a charger is brought into contact with the photoconductive layer of the photosensitive drum, a predetermined bias voltage is applied to the charger from a charging power source, and the photoconductive layer is charged to a predetermined voltage to charge the charging drum. A fast-acting fuse is provided on the input side of the power supply via a current detection resistor. This fast-acting fuse is blown when the current flowing into the charging power supply exceeds a predetermined value, and when the control circuit detects it, the supply roller and the developing roller In addition, an image forming apparatus is described in which supply of a bias voltage to a transfer roller or the like is stopped to stop a printing process, and only a motor is rotated for a predetermined time to perform paper discharge processing.

  In Patent Document 3, the transfer bias current supplied to the transfer roller by the transfer bias generation circuit is set to a constant value by the constant current transformer, and the magnitude of the transfer bias current supplied from the constant current transformer to the transfer roller is set by the current detection circuit. When the transfer bias current is constantly monitored and the transfer bias current is supplied to the transfer roller, the resistance value of the ionic conductive elastic body of the transfer roller increases and the magnitude of the transfer bias current decreases to a current value that may cause transfer failure. An image forming apparatus is described in which an image forming operation of the apparatus is stopped by notifying a CPU of a current value from a current detection circuit.

Patent Document 4 discloses a latent image carrier, a latent image writing unit, a color developing device, an intermediate transfer member, a primary transfer roller, a voltage applying unit that forms a transfer electric field in the primary transfer unit, and a voltage applied to the primary transfer roller. Voltage detecting means for detecting the image, a secondary transfer roller that presses against the intermediate transfer member and secondarily transfers the toner image carried on the intermediate transfer member onto the recording medium, and an image forming condition for adjusting the image forming condition And a control method of the image forming apparatus that controls the image forming condition adjusting means by a detection signal of the voltage applying means.
A system for reporting an abnormality to an apparatus support center via a wired or wireless interface, a communication adapter, or a public line network when the apparatus has an abnormality is widened and put into practical use by Patent Document 5 and the like. ing.

  In the above control method, for example, destruction of the power pack can be avoided. However, this is insufficient to prevent destruction of the photoreceptor. This is because the bias applied to the photoconductor is variably controlled depending on the printing mode and the surrounding environment, and cannot be determined to be abnormal with a certain threshold. For example, if a threshold value is set higher than all the bias values that can be controlled, a photosensitive region to which a low bias should be applied has already become a destructive region when the threshold value is reached. There is a possibility. On the other hand, when the threshold value is set in such a way that the photoconductor in all states is not destroyed, for the photoconductor to which a high bias is to be applied, only an insufficient bias is obtained below the threshold value. Functions (functions such as charging, developing, and transferring) may not be obtained.

An object of the present invention is to provide an image forming apparatus that can prevent excessive bias application due to abnormal rotation of a photoconductor in any state and can protect the photoconductor. It is to provide.
Another object of the present invention is to provide an image forming apparatus capable of specifying the location where an abnormality has occurred and reducing the time required for repair.
Another object of the present invention is to provide an image forming apparatus capable of controlling a threshold without excess or deficiency.

Another object of the present invention is to provide an image forming apparatus capable of more accurately controlling a threshold value.
Another object of the present invention is to provide an image forming apparatus capable of controlling a threshold value with a simple mechanism.
Another object of the present invention is to provide an image forming apparatus that can prevent the destruction of the photosensitive member and can be used without replacing the photosensitive member even after repairing an abnormal portion.

Another object of the present invention is to automatically notify the remote centralized management device that an abnormality has occurred in the image forming apparatus, enabling a quick response to the abnormality in the image forming apparatus, and reducing the downtime of the apparatus. An object of the present invention is to provide an image forming apparatus and a remote centralized management system that can be reduced.
Another object of the present invention is that a customer engineer can make necessary and sufficient preparations to visit a device that has reported an abnormality, and perform device repair and parts replacement work in the minimum necessary time. It is an object to provide an image forming apparatus and a remote centralized management system.
Another object of the present invention is to provide an image forming apparatus capable of providing services such as replenishment of supplies such as toner and transfer material at the same time as well as dealing with abnormalities, and effectively utilizing the opportunity of visits. And providing a remote centralized management system.

  In order to achieve the above object, the invention according to claim 1 is provided to the contact-type bias applying unit in an image forming apparatus having a contact-type bias applying unit that applies a bias to the photoconductor in contact with the photoconductor. Detection means for detecting a voltage value or current value to be detected, and an abnormality detection means for comparing an output value of the detection means with a threshold value and detecting a rotation abnormality of the photoconductor based on the contrast magnification, and the threshold value Is variable.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, a rotation detecting means for detecting the rotation of the photosensitive member, an output signal of the rotation detecting means, and an output signal of the abnormality detecting means are used to identify a failure site. And a failure part specifying means for specifying.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the threshold value is controlled with reference to information obtained by at least one information detecting means.

  According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, one of the information detection means detects one or more of the temperature, relative humidity, and absolute humidity around the image forming apparatus. The threshold value is controlled with reference to detection information of the environmental sensor.

  According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, an ion conductive material is used for the contact-type bias applying unit.

  According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the third to fifth aspects, the referenced information includes information on a charging potential of the photosensitive member.

  According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the third to sixth aspects, the referenced information includes information on a process linear velocity.

  According to an eighth aspect of the present invention, in the image forming apparatus according to any one of the first to seventh aspects, when the abnormality detecting unit detects the rotation abnormality, the voltage to the contact-type bias applying unit is determined. And the supply of current is stopped.

  According to a ninth aspect of the present invention, in the image forming apparatus according to any one of the first to eighth aspects, when the abnormality detection unit detects an abnormality, the occurrence and contents of the abnormality are remotely concentrated as abnormality information. It has a reporting means for automatically reporting to the management device.

  According to a tenth aspect of the present invention, in the image forming apparatus according to any one of the first to eighth aspects, when the abnormality detection unit detects an abnormality, the part that caused the abnormality is automatically identified. Information on repair tools and parts necessary for identifying and restoring to a normal state is automatically notified to the remote centralized management device by the reporting means together with the abnormality information.

  According to an eleventh aspect of the present invention, in the image forming apparatus according to the ninth or tenth aspect, when the abnormality detection unit detects an abnormality, information on a usage status of the apparatus other than the abnormality information is referred to as the abnormality information. In addition, the notification means automatically notifies the remote centralized management apparatus.

  According to a twelfth aspect of the present invention, in the remote centralized management system that manages a plurality of image forming apparatuses by a remote centralized management apparatus, at least one of the plurality of image forming apparatuses is any one of the first to eighth aspects. When the abnormality detecting means detects an abnormality, the image forming apparatus automatically reports the occurrence and contents of the abnormality to the remote centralized management apparatus as abnormality information. It has a reporting means to do.

  According to a thirteenth aspect of the present invention, in the remote centralized management system for managing a plurality of image forming apparatuses by a remote centralized management apparatus, at least one of the plurality of image forming apparatuses is any one of the first to eighth aspects. When the abnormality detecting means detects an abnormality, the image forming apparatus automatically identifies the part that caused the abnormality and restores it to a normal state. For this purpose, information on repair tools and parts necessary for this purpose is automatically reported to the remote centralized management device by the reporting means together with the abnormality information.

  According to a fourteenth aspect of the present invention, in the remote centralized management system for managing a plurality of image forming apparatuses by a remote centralized management apparatus, at least one of the plurality of image forming apparatuses is any one of the first to eighth aspects. When the abnormality detecting unit detects an abnormality, the image forming apparatus uses information on the usage status of the image forming apparatus other than the abnormality information as the abnormality information. In addition, the notification means automatically notifies the remote centralized management apparatus.

According to the present invention, it is possible to prevent excessive bias application due to abnormal rotation of the photosensitive member to the photosensitive member used in any state, and to protect the photosensitive member.
According to the present invention, the location where an abnormality has occurred can be identified, and the time required for repair can be reduced.

According to the present invention, the threshold value can be controlled without excess or deficiency.
According to the present invention, the threshold value can be controlled more accurately.
According to the present invention, the threshold value can be controlled with a simple mechanism.
According to the present invention, it is possible to prevent destruction of the photoconductor, and it is possible to use the photoconductor without exchanging it even after repairing an abnormality occurrence location.

According to the present invention, it is possible to automatically report to the remote centralized management device that there is an abnormality in the image forming apparatus, and it is possible to quickly respond to the abnormality in the image forming apparatus and reduce the downtime of the apparatus. be able to.
According to the present invention, it is possible for a customer engineer or the like to make necessary and sufficient preparations to visit a device that has reported an abnormality, and to perform device repair and parts replacement work in the minimum necessary time. .
According to the present invention, it is possible not only to deal with abnormalities, but also to provide services such as replenishment of supplies such as toner and transfer material at the same time, and it is possible to make effective use of visit opportunities.

It is sectional drawing which shows one Embodiment of this invention. It is sectional drawing which expands and shows the image formation part in the embodiment. FIG. 3 is a cross-sectional view showing an intermediate transfer member cleaning device in the same embodiment. It is sectional drawing which shows the photoconductor cleaning apparatus in the embodiment. FIG. 4 is a block diagram illustrating a portion that performs transfer bias control during normal image formation in the embodiment. It is a block diagram which shows the part which performs control at the time of the photoconductor rotation abnormality detection in the same embodiment. It is a block diagram which shows the remote centralized management system which is other embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this description, specific member names are used to facilitate understanding of the invention, but it should be noted here that the scope of the present invention is not limited thereby.
FIG. 1 shows an image forming apparatus comprising a tandem type intermediate transfer type electrophotographic apparatus according to an embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes a tandem image forming apparatus that forms an image of each color on a plurality of photoconductors, 2 denotes a writing optical apparatus as an exposure apparatus that exposes the photoconductors, and 3 denotes a supply that supports the entire embodiment. A paper table, 4 is a conveying / reversing device that conveys a transfer material as a recording member, 5 is a fixing device that finally fixes an image to the transfer material, 9 is a paper discharge roller, and 10 is a paper discharge tray.

  FIG. 2 shows an enlarged image forming portion of the present embodiment. The tandem image forming apparatus 1 is provided with an endless belt-shaped intermediate transfer member 501 at the center. The intermediate transfer member 501 is composed of rubber or resin having a single layer structure or a multilayer structure. The intermediate transfer member 501 is stretched around a secondary transfer bias roller 502 and support rollers 503, 508, and 509, and can rotate counterclockwise in the illustrated example. Further, a secondary transfer unit 600 is disposed opposite to the secondary transfer bias roller 502 across the intermediate transfer member 501.

  A secondary transfer bias roller 502 as a secondary transfer electric field forming unit is applied with a predetermined transfer bias from a power supply (power pack) (not shown) to form an electric field having the same polarity as the charging polarity of the toner. The toner on the intermediate transfer member 501 is secondarily transferred to a transfer material by using electric force. Also, an intermediate transfer body cleaning device 520 that removes residual toner remaining on the intermediate transfer body 501 after image transfer is provided on the left of the support roller 509.

  FIG. 3 shows an enlarged view of the intermediate transfer member cleaning device 520. The intermediate transfer body cleaning device 520 includes a blade member 521 for removing toner, a coil member 524 for conveying the removed toner to a waste toner tank of the main body of this embodiment, a lubricant 523, and a lubricant application. And a brush 522. The contact angle, position, pressure, and the like of the blade member 521 with respect to the intermediate transfer member 501 are appropriately set depending on the toner used, the image forming speed of the apparatus, and the like. The lubricant 523 is pressed against the lubricant application brush 522 by means such as a spring or a weight, and the lubricant application brush 522 performs an operation of scraping the lubricant 523 and applying it to the intermediate transfer body 501 while rotating.

  Further, inside the intermediate transfer member 501 between the support roller 503 and the support roller 508, primary transfer bias rollers 504, 505, 506, and 507 as primary transfer electric field forming means for forming a transfer electric field at the time of primary transfer are intermediate transfer members. It arrange | positions in the state which can contact 501. FIG. Four photosensitive materials for yellow, cyan, magenta, and black are arranged along the conveying direction of the intermediate transfer member 501 on the opposite side of the intermediate transfer member 501 from the primary transfer bias rollers 504, 505, 506, and 507. The tandem image forming apparatus 1 is configured by horizontally arranging the bodies 101, 102, 103, and 104.

Around each of the photoconductors 101 to 104, photoconductor charging units 201 to 204, photoconductor cleaning units 301 to 304, and developing units 401 to 404 are arranged, respectively.
FIG. 4 shows details of the cleaning means 301-304. The cleaning units 301 to 304 are respectively a blade member 311 for removing toner on the photoconductors 101 to 104, a coil member 314 for conveying the removed toner to a waste toner tank of the main body of the present embodiment, It has a lubricant 313 and a lubricant application brush 312. The contact angle, position, pressure, and the like of the blade member 311 with respect to the photoconductors 101 to 104 are appropriately set depending on the toner used, the image forming speed of the apparatus, and the like. The lubricant 313 is pressed against the lubricant application brush 312 by means 315 such as a spring or a weight, and the lubricant application brush 312 performs an operation of scraping the lubricant 313 and applying it to the photoreceptors 101 to 104 while rotating.

  Write exposure to the photoconductors 101 to 104 is performed by laser light modulated by image signals of each color by the write optical device 2 as an exposure device at a position between the photoconductor charging units 201 to 204 and the developing units 401 to 404. Is performed by irradiating the photoconductors 101 to 104 respectively. A registration roller 800 for feeding the transfer material to the secondary transfer unit is installed below the secondary transfer unit 600, and a fixing device 700 for fixing the toner image on the transfer material is installed above the secondary transfer unit 600. Is provided.

  When an image forming operation is performed using the color electrophotographic apparatus of this embodiment, first, an image signal is input from a personal computer or a scanner (not shown). At a predetermined timing after the input of the image signal, the photoconductors 101 to 104 and the intermediate transfer body 501 are driven to rotate by a drive motor (not shown), and at the same time, the photoconductors 101 to 104 are cleaned by the photoconductor cleaning units 301 to 304. A preliminary cleaning operation is performed.

  Thereafter, the photoconductors 101 to 104 are uniformly charged by the photoconductor charging units 201 to 204, respectively, and exposed to laser light by the writing optical device 2 to form an electrostatic latent image. The electrostatic latent images on the photoconductors 101 to 104 are developed by developing units 401 to 404, respectively, to become toner images of yellow, cyan, magenta, and black.

  A power pack (not shown) as a power supply device applies a primary transfer bias to the photoconductors 101 to 104 via the primary transfer bias rollers 504 to 507 and the intermediate transfer body 501, thereby forming a transfer electric field having a polarity opposite to the charged polarity of the toner. Then, the toner images of the respective colors on the photoconductors 101 to 104 are superposed on the intermediate transfer member 501 at the predetermined timing and primarily transferred by this transfer electric field, thereby forming a full color image. Note that if a toner image is formed on only one or two of the photoconductors 101 to 104, a monochromatic or bicolor image is formed on the intermediate transfer body 501. Toner remaining on the photoreceptors 101 to 104 without being completely transferred onto the intermediate transfer member 501 is cleaned by the photoreceptor cleaning means 301 to 304, respectively.

  On the other hand, after the input of the image signal, a transfer sheet as a transfer material is fed from the sheet feed table 3 at a predetermined timing, and the transfer sheet hits the registration roller 800 and stops. The registration roller 800 rotates in synchronization with the image on the intermediate transfer member 501 to send out transfer paper, and this transfer paper is sent between the intermediate transfer member 501 and the secondary transfer unit 600.

  A power pack (not shown) as a power supply device applies a transfer bias to the secondary transfer bias roller 502 to form a transfer electric field having the same polarity as the charged polarity of the toner, and the image on the intermediate transfer member 501 is transferred onto the transfer paper by the transfer electric field. Secondary transfer is performed. The transfer paper is fixed with an image by applying heat and pressure by the fixing device 700, and is discharged onto the paper discharge tray 10 by the paper discharge roller 9. The toner remaining on the intermediate transfer member 501 without being completely transferred onto the transfer paper during the secondary transfer is removed by the intermediate transfer member cleaning device 520 to prepare for the image formation again.

Next, control of the bias applied to the photoconductors 101 to 104 will be described.
Here, transfer bias rollers 504 to 507 will be described as an example of contact-type bias applying means for applying a bias to the photoreceptors 101 to 104 in contact with the photoreceptors 101 to 104.
FIG. 5 schematically shows the control of the transfer bias. When the transfer operation is started, transfer bias is applied from the power pack 6 to the transfer bias rollers 504 to 507, respectively. However, the power pack 6 is controlled by the control signal from the microcomputer (CPU) 7 as the control means to the power pack 6. The transfer bias is output according to the control value from. Here, the power pack 6 is subjected to constant current control so that the output current is constant.

The transfer bias is applied from the power pack 6 to the photoconductors 101 to 104 via the transfer bias rollers 504 to 507 and the intermediate transfer body 501, thereby forming a transfer electric field, and the toner on the photoconductors 101 to 104 is formed by this transfer electric field. Is primarily transferred onto the intermediate transfer member 501. At the end of the transfer operation, an output-off signal is output from the CPU 7 to the power pack 6, and the power pack 6 stops applying the transfer bias to the transfer bias rollers 504 to 507.
During these operations, the CPU 7 controls the power pack 6 so that an appropriate current value is applied to the photoconductors 101 to 104 based on information from a sensor that detects information such as temperature and humidity.

In the present embodiment, the threshold value that determines the upper limit of the output voltage (or output current) of the power pack 6 corresponding to the bias applied to the photoconductors 101 to 104 variably controlled according to the situation is variably set. In addition, excessive bias application due to abnormal rotation of the photoconductors 101 to 104 is prevented, and the photoconductors 101 to 104 are protected. Next, this point will be described.
If the rotation of the photoconductors 101 to 104 is stopped due to some abnormality during the normal primary transfer operation as described above, the supply of electric charges due to the rotation of the photoconductors 101 to 104 is stopped. The resistance value of the transfer bias supply system will increase. In the case of constant current control as in this embodiment, the voltage value increases due to the increase in the voltage value.

  Therefore, in this embodiment, as shown in FIG. 6, a switch 8 is provided between each of the power pack 6 and the transfer bias rollers 504 to 507, and this switch 8 is normally turned on (closed). . In addition, a detection unit that detects a voltage (or current) supplied from the power pack 6 to the transfer bias rollers 504 to 507 is provided. The CPU 7 compares (contrasts) the output value of the detection means with a threshold value and detects an abnormal rotation of the photoconductors 101 to 104 based on the comparison result (contrast magnification) (abnormality detection means). When the rotation abnormality of the photoconductors 101 to 104 is detected by this abnormality detection function (when the output value of the detection means reaches the threshold value), the switch 8 is turned off (opened) and the output of the power pack 6 is output. (Current and voltage) are stopped, and the image forming operation of the present embodiment is stopped. Further, the CPU 7 variably controls the threshold value according to the state of the present embodiment so that the photoconductors 101 to 104 are not destroyed even when a voltage value up to the threshold value is applied to the photoconductors 101 to 104.

  As described above, in the present embodiment, the voltage (or current) supplied from the power pack 6 is detected with respect to the transfer bias rollers 504 to 507 serving as contact-type bias applying units that contact the photoconductors 101 to 104. An abnormality detection means for detecting a rotation abnormality (such as unintentional rotation stop) of the photoconductors 101 to 104 based on the comparison magnification is provided, and the threshold value is variably controlled according to the state of the present embodiment. By doing so, it is possible to prevent voltage breakdown and current breakdown of the photoconductors 101 to 104 used in any state.

  Further, as shown in FIG. 6, a rotation detecting means 11 for detecting the rotation of the motor by detecting the electric power supplied from the power supply circuit to the motor for driving the photoconductors 101 to 104 is provided. From the detection result of the rotation detecting means 11, when the rotation abnormality of the photoconductors 101 to 104 occurs, the abnormality occurrence location can be specified. That is, if the power supplied to the motor is zero, the CPU 7 determines that the motor itself is out of order, and if the power supplied to the motor is considerably higher than normal, it is due to the torque up of the photoconductors 101 to 104. If the power supplied to the motor is low, it is determined that the drive transmission system such as a gear that transmits driving force from the motor to the photoconductors 101 to 104 is missing, and the determination result is displayed on the display device. Let

  Thus, in this embodiment, by providing the rotation detection means 11 for detecting the rotation of the motor that drives the photoconductors 101 to 104, the cause of abnormal rotation of the photoconductors 101 to 104 is that the motor does not rotate ( Motor failure, or no signal from the CPU 7 to the power pack that drives the motor), motor driving force transmission system failure (gear damage, coupling meshing failure, etc.) and torque It can be distinguished whether it is up. As a result, the location where the abnormality has occurred can be identified, and the time required for repairing can be shortened.

Further, the CPU 7 controls the threshold value for detecting the rotation abnormality of the photoconductors 101 to 104 to an appropriate value based on information such as the transfer bias voltage detected when the transfer bias output value is controlled. The threshold value is controlled to a threshold value corresponding to the magnitude of the transfer bias output value.
As described above, in this embodiment, the bias applied to the photoconductors 101 to 104 is variably controlled according to various conditions. By detecting information on the conditions and changing the threshold value, the threshold value is changed. Can be controlled without excess or deficiency.

The transfer bias rollers 504 to 507 are made of an ion conductive material, and are provided with an environmental sensor that detects one or more of the temperature, relative humidity, and absolute humidity around the present embodiment. The CPU 7 variably controls the threshold value with reference to the detection information of the environmental sensor.
The temperature, humidity, and absolute humidity around the present embodiment are one piece of important information for determining the bias applied to the photoconductors 101 to 104. This is because the resistances of the photoconductors 101 to 104 themselves, bias applying means for applying a bias to the photoconductors 101 to 104, and other members to be energized are changed. By detecting these, the threshold value can be controlled more accurately.

  It is well known that the resistance value of the ion conductive material has a correlation with the absolute humidity, and the transfer bias rollers 504 to 507 use the ion conductive material to change the effective voltage value applied to the photoconductors 101 to 104. Since it can be determined, the threshold value can be accurately controlled. That is, medium resistance materials are often used for the transfer bias rollers 504 to 507 as contact bias applying means for the photoconductors 101 to 104, and a carbon dispersion type, an ion conductive type, and the like are in practical use. Among these, the ion conductive type has a feature that the resistance value is substantially constant regardless of the applied bias value, and the correspondence between the output value of the power pack 6 and the bias value applied to the photoconductors 101 to 104. Is linear, the threshold value can be easily controlled. This is because if the resistance value of the contact-type bias applying means changes according to the output of the power pack, a function or a table for reflecting the change in the threshold value is required.

Further, charging potential detection means for obtaining the charging potential of the photosensitive members 101 to 104 by detecting the output values of the photosensitive member charging means 201 to 204 is provided, and the CPU 7 performs the above operation based on the detection information of the charging potential detection means. Control the threshold.
The charging potential of the photoconductors 101 to 104 particularly affects the resistance of the entire transfer system. As an example, when considering a negative-negative developing system (a system in which the photosensitive members 101 to 104 are negatively charged and developed with negatively charged toner), the resistance of the transfer system decreases as the charged potential of the photosensitive members 101 to 104 decreases. By detecting the charging potential information of the photoconductors 101 to 104 by the charging potential detection means and controlling the threshold value based on the information, the threshold value can be controlled more accurately.

  Also, considering the normal paper 600 × 600 dpi mode as the normal mode, the half-speed mode, which is the process line speed half that of the normal mode, can be selected for image formation with 1200 × 1200 dpi images, thick paper, and special paper. In this case, since the rotation speeds of the photoconductors 101 to 104 are also halved, the transfer bias at that time is also approximately halved. In such a case, the CPU 7 controls the threshold value based on the information that the mode is the half speed mode.

  Many image forming apparatuses such as recent copying machines, printers, and multifunction machines can change the linear speed (image forming speed) depending on the resolution and the transfer material used. If the linear velocity changes, the rotational speed of the image forming system called the process linear velocity also changes, so that the bias to be applied to the photoconductors 101 to 104 also changes accordingly. The CPU 7 more accurately controls the threshold value based on the process linear velocity information.

  Thus, in the present embodiment, the threshold value is compared with the output voltage of the power pack 6, and when the output voltage of the power pack 6 reaches the threshold value, the output of the power pack 6 is immediately stopped. Thereby, destruction by the overvoltage of the photoconductors 101 to 104 can be prevented, and the photoconductors 101 to 104 can be used without being replaced even after repairing the abnormality occurrence portion.

As described above, according to the present embodiment, since the threshold value for determining the rotation abnormality of the photosensitive member is variable, an appropriate threshold value can be set according to the state of the apparatus, and the destruction of the photosensitive member can be prevented.
According to the present embodiment, it is possible to identify the location where an abnormality has occurred, rationalize the repair work, and shorten the apparatus off time.
According to the present embodiment, the threshold value can be controlled without excess or deficiency by detecting at least one piece of information.

According to this embodiment, the threshold value can be more accurately controlled by reflecting the temperature and humidity information around the apparatus.
According to this embodiment, by using an ion conductive material for the contact-type bias applying means, even if the bias value applied to the photoconductor takes various values, the resistance value of the ion conductive material hardly changes and the contact value is applied to the photoconductor. The threshold can be controlled in accordance with the effective bias.

According to this embodiment, the threshold value can be more accurately controlled in consideration of the influence of the photosensitive member charging potential.
According to this embodiment, the threshold value can be controlled corresponding to the image forming mode.
According to this embodiment, since the bias application to the photosensitive member is stopped when the voltage value or current value supplied to the contact-type bias applying unit reaches the threshold value, it is possible to prevent destruction of the photosensitive member. It can be used after repair of rotation abnormality, and there is a merit that leads to cost reduction and environmental protection for equipment users.

  FIG. 7 shows a remote centralized management system according to another embodiment of the present invention. This remote centralized management system is composed of a remote centralized management apparatus 601 and electronic devices 602 and 603 installed at each customer. The remote centralized management apparatus 601 is composed of a center system such as a service support center, and an exchange at each customer is not shown. The electronic devices 602 communicate with the communication adapter 605 connected to the center system 601 via the public network 604, a plurality of image forming apparatuses including a copier 606, a printer 607, and a facsimile apparatus 608, and these image forming apparatuses. And a dedicated interface (hereinafter referred to as I / F) line 609 for connecting to the adapter 605.

  The electronic devices 603 communicate with the communication adapter 610 connected to the center system 601 via the public network 604, a plurality of image forming apparatuses including a copier 611, a printer 612, and a facsimile apparatus 613, and these image forming apparatuses. A dedicated I / F line 614 for connecting the adapter 610 is included. The copiers 606 and 611 are configured in the same manner as in the above embodiment. The printers 607 and 612 and the facsimile machines 608 and 613 are constituted by an electrophotographic apparatus as in the above embodiment, and are provided with a transfer bias control means as shown in FIG. The dedicated I / F lines 609 and 614 can have a wired configuration or a wireless configuration, but in this embodiment, have a wired configuration.

  The center system 601 connects a plurality of computers 615, 616,... Via a network 617 such as a LAN (local area network) and the like via a public telephone network 604, a communication adapter 605, and a dedicated I / F line 609. A plurality of image forming apparatuses including a copying machine 606, a printer 607, and a facsimile apparatus 608 are centrally managed, and a copying machine 611, a printer 612, and a facsimile apparatus are provided via a public telephone line network 604, a communication adapter 610, and a dedicated I / F line 614. A plurality of image forming apparatuses including 613 are centrally managed.

  Each of the computers 615 and 616 of the center system 601 includes a CPU, a display device, an input device such as a keyboard, a communication control unit that controls communication with an external device via the public telephone line network 604, and the like. The control units of the copiers 606 and 611 include the CPU 7 and a personal I / F that controls communication with the communication adapters 605 and 610. Similarly, the control units of the printers 607 and 612 and the control units of the facsimile apparatuses 608 and 613 include a CPU and a personal I / F that controls communication with the communication adapters 605 and 610.

  The copiers 606, 611, the printers 607, 612, and the facsimile apparatuses 608, 613 are supplied from the power pack to the transfer bias roller as contact-type bias applying means that contacts the photoconductor, as in the above-described embodiment. Detecting the detected voltage (or current) and comparing it with the threshold, and detecting the rotation of the photoconductor (unintentional rotation stop, etc.) based on the comparison magnification, and the rotation detecting the rotation of the photoconductor It has a detection means. The control units (CPUs) of the copying machines 606, 611, printers 607, 612, and facsimile apparatuses 608, 613 detect the rotation detecting means when the abnormality detecting means detects a rotation abnormality of the photosensitive member. From the results, the cause of abnormal rotation of the photoconductor is that the motor that rotates the photoconductor does not rotate (the motor is out of order, the power pack that drives the motor does not receive a signal from the CPU, etc.) It is distinguished whether there is a motor drive force transmission system failure (gear damage, coupling meshing failure, etc.) or torque increase, and if the power supplied to the motor is zero, the motor itself is faulty. If the power supplied to the motor is considerably higher than normal, it is determined that the photoconductors 101 to 104 are stopped due to torque increase. If the power supplied to the sensor is low, it is determined that the drive transmission system such as a gear that transmits the driving force from the motor to the photosensitive member is missing, etc. / F lines 609 and 614, communication adapters 605 and 610, and the public telephone line network 604 are notified to the center system 601.

  The control units of the copiers 606 and 611, the printers 607 and 612, and the facsimile apparatuses 608 and 613 respectively detect the power supplied from the power supply circuit to the motor that drives the photoconductor, as in the above embodiment. Thus, from the detection result of the rotation detecting means for detecting the rotation of the motor, the location where the abnormality occurs when the rotation abnormality of the photosensitive member occurs, that is, if the power supplied to the motor is zero, the motor itself If it is determined that there is a failure and the power supplied to the motor is considerably higher than normal, it is determined that the photoconductor is stopped due to torque increase. Conversely, if the power supplied to the motor is low, the motor drives the photoconductor. It is determined that the drive transmission system such as a gear that transmits force is missing, etc., and the cause of abnormal rotation of the photoconductor is that the motor does not rotate (the motor has failed, the motor is If the power pack does not receive a signal from the CPU), the motor drive force transmission system is faulty (gear damage, coupling meshing failure, etc.) or the torque is increased. In addition, determine the repair parts and replacement parts necessary to restore the normal state from the location where the abnormality occurred, and repair parts and replacement parts necessary to repair the abnormal place to the normal state. The information and the cause of the rotation abnormality of the photosensitive member are combined with the abnormality information and notified to the center system 601 via the dedicated I / F lines 609 and 614, the communication adapters 605 and 610, and the public telephone line network 604. .

  The computers 615 and 616 of the center system 601 receive information notified from the image forming apparatus via the public telephone network 604 and display the information on the display device, and copy machines 606 and 611, printers 607 and 612, and facsimile apparatuses 608. , 613, and the content of the abnormality is reported and displayed on the display device, the customer engineer or the like reports the status of the image forming apparatus that has received the notification from the display content of the display device. The installation site of the image forming apparatus is visited for confirmation and repair. At this time, the customer engineer, etc. prepares necessary preparations by knowing in advance from the report the location where the abnormality occurred in the image forming device and the repair parts and replacement parts necessary to restore it to the normal state. It is possible to visit the place where the image forming apparatus is installed, and it is possible to repair the part where the abnormality occurs in the image forming apparatus and replace parts in the minimum necessary time. For example, if the cause of the abnormality is that the motor does not rotate, a replacement motor or harness may be required, and a continuity check is required to identify the location of the detailed abnormality. , Etc. Information is provided to customer engineers. Also, if the cause of the abnormality is an abnormality in the motor drive force transmission system, customer engineer will provide information such as the need for a replacement gear, grease for improving slidability, and a torque gauge for torque measurement. To provide. By obtaining such information, the customer engineer can know the parts to be repaired and replaced in advance, bring the necessary parts and tools, and can smoothly work at the site.

  The control units of the copiers 606 and 611, the printers 607 and 612, and the facsimile apparatuses 608 and 613 respectively include a toner consumption measuring unit that measures the amount of toner consumed by the developing unit and an image forming unit. Image forming number measuring means for measuring the number of sheets (image forming number), toner end detecting means for detecting the toner end of the toner replenishing device that replenishes toner to the developing means, etc. Detecting the toner consumption measured by the toner consumption measuring means, the image forming number measured by the image forming number measuring means, the toner end detected by the toner end detecting means, the full color ratio of the image formed product, and the image area ratio detecting means Information etc.) together with the above abnormal information etc., dedicated I / F lines 609, 614, communication adapters 605, 610, public To report to the center system 601 via the telephone line network 604.

  Customer engineers, etc. not only respond to abnormalities in the image forming device that was reported from the display contents of the display device, but also provide services such as replenishment of supply (toner and transfer material) at the same time, making the opportunity of visits effective Take advantage of. Also, a customer engineer, etc., displays the toner end display on the image forming device based on the display contents of the display device, but if the toner is not ordered, bring the appropriate toner to the customer. In the usage situation where the full color ratio or image area ratio of the image formation is high, it is assumed that there may be toner scattering in the apparatus, and bring the tools necessary for cleaning. Accordingly, it is possible to improve the profit of the user without wasting a visit opportunity by capturing an unfavorable situation such as an abnormality of the image forming apparatus and providing finer service and support than usual.

As described above, according to this embodiment, it is possible to promptly respond to the rotation abnormality of the photosensitive member by automatically notifying that the rotation abnormality of the photosensitive member has occurred, and to reduce the downtime of the image forming apparatus. can do.
According to the present embodiment, by knowing in advance by notification that the part to be repaired or parts replaced of the image forming apparatus, the customer engineer can make necessary and sufficient preparations and visit the image forming apparatus installation location. Repair and parts replacement work can be done in a minimum amount of time.
According to the present embodiment, it is possible to know not only abnormality information but also information on the apparatus usage status (toner consumption, number of images formed, etc.) in a unified manner. Services can be provided at the same time, and an opportunity to visit an image forming apparatus installation location can be effectively utilized.

DESCRIPTION OF SYMBOLS 1 Tandem image forming apparatus 2 Photoconductor exposure means 3 Paper feed table 4 Conveying / reversing device 5 Fixing device 6 Power pack 7 CPU
11 Rotation detection means 100 to 104 Photoconductor drums 201 to 204 Photoconductor charging means 301 to 304 Photoconductor cleaning means 401 to 404 Development means 501 Intermediate transfer body 502 Secondary transfer bias rollers 503, 508, 509 Support rollers 504 to 507 1 Next transfer bias roller 520 Intermediate transfer member cleaning means 600 Secondary transfer unit 700 Fixing device 800 Registration roller 601 Remote centralized management device 602, 603 Electronic equipment 604 Public line network 605, 610 Communication adapter 606, 611 Copier 607, 612 Printer 608, 613 Facsimile devices 609, 614 Dedicated I / F line

Japanese Patent Laid-Open No. 11-65236 Japanese Patent Laid-Open No. 11-311892 Japanese Patent Laid-Open No. 11-311564 JP-A-9-236964 JP 2001-142361 A

Claims (14)

In an image forming apparatus having contact-type bias applying means for applying a bias to the photoreceptor in contact with the photoreceptor,
Detecting means for detecting a voltage value or a current value supplied to the contact-type bias applying means;
An image forming apparatus comprising: an abnormality detection unit that compares an output value of the detection unit with a threshold value and detects a rotation abnormality of the photoconductor based on a comparison magnification; and the threshold value is variable.   2. The image forming apparatus according to claim 1, further comprising: a rotation detection unit that detects rotation of the photosensitive member; and a failure part specifying unit that specifies a failure part based on an output signal of the rotation detection unit and an output signal of the abnormality detection unit. An image forming apparatus comprising:   3. The image forming apparatus according to claim 1, wherein the threshold value is controlled with reference to information obtained by at least one information detection unit.   4. The image forming apparatus according to claim 3, wherein one of the information detection means is an environmental sensor that detects one or more of a temperature, a relative humidity, and an absolute humidity around the image forming apparatus. An image forming apparatus, wherein the threshold value is controlled with reference to information.   5. The image forming apparatus according to claim 1, wherein an ion conductive material is used for the contact-type bias applying unit.   6. The image forming apparatus according to claim 3, wherein the reference information includes information on a charging potential of the photosensitive member.   7. The image forming apparatus according to claim 3, wherein the information to be referred includes information on a process linear velocity.   8. The image forming apparatus according to claim 1, wherein when the abnormality detection unit detects the rotation abnormality, supply of voltage and current to the contact-type bias applying unit is stopped. An image forming apparatus.   9. The image forming apparatus according to claim 1, wherein when the abnormality detecting unit detects an abnormality, the occurrence and contents of the abnormality are automatically notified to the remote centralized management apparatus as abnormality information. An image forming apparatus comprising a reporting unit.   9. The image forming apparatus according to claim 1, wherein when the abnormality detection unit detects an abnormality, the part that caused the abnormality is automatically identified and restored to a normal state. An image forming apparatus characterized in that information on repair tools and parts necessary for this is automatically reported to the remote centralized management apparatus by the reporting means together with the abnormality information.   11. The image forming apparatus according to claim 9, wherein when the abnormality detection unit detects an abnormality, information on a usage status of the apparatus other than the abnormality information is combined with the abnormality information to the remote centralized management apparatus. An image forming apparatus that automatically reports by the reporting means.   9. The remote centralized management system for managing a plurality of image forming apparatuses by a remote centralized management apparatus, wherein at least one image forming apparatus among the plurality of image forming apparatuses is an image forming apparatus according to any one of claims 1 to 8. The image forming apparatus includes a reporting unit that automatically reports the occurrence and contents of the abnormality to the remote centralized management apparatus as abnormality information when the abnormality detecting unit detects the abnormality. Remote centralized management system featuring.   9. The remote centralized management system for managing a plurality of image forming apparatuses by a remote centralized management apparatus, wherein at least one image forming apparatus among the plurality of image forming apparatuses is an image forming apparatus according to any one of claims 1 to 8. The image forming apparatus comprises a repair tool or a part necessary for automatically identifying a part causing the abnormality and restoring it to a normal state when the abnormality detecting means detects the abnormality. The information is automatically reported to the remote centralized management apparatus by the reporting means together with the abnormality information.   9. The remote centralized management system for managing a plurality of image forming apparatuses by a remote centralized management apparatus, wherein at least one image forming apparatus among the plurality of image forming apparatuses is an image forming apparatus according to any one of claims 1 to 8. When the abnormality detection unit detects an abnormality, the image forming apparatus includes information on the usage status of the image forming apparatus other than the abnormality information together with the abnormality information to the remote centralized management apparatus. A remote centralized management system characterized in that notification is automatically made by the reporting means.

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