JP6922315B2 - Presence / absence determination device for rotating members and image forming device - Google Patents

Description

The present invention relates to a device for determining the presence or absence of a rotating member and an image forming device.

Patent Document 1 describes an image forming unit formed by providing a photoconductor and a charging means adjacent to the photoconductor and detachable from the main body of the apparatus, an AC high-voltage amplifier circuit that supplies high-voltage alternating current to the charging means, and the AC. An AC current detection circuit that detects the AC current of the output from the high-voltage amplifier circuit, a differential voltage amplifier that amplifies the difference voltage between the output voltage of the AC current detection circuit and the first reference voltage, and the output voltage of the difference voltage amplifier. A variable amplitude transmitter that changes the waveform amplitude of the AC output voltage and inputs it to the AC high-voltage amplifier circuit is provided. An image forming apparatus that forms an image, attaches a recording agent to the latent image, obtains a visible image, and transfers and records it on a recording medium. A comparison comparing the output voltage of the AC current detection circuit with a second reference voltage. An image forming apparatus is disclosed, which comprises a mounting detecting means for detecting the mounting of the detachable image forming unit provided with a device.

Japanese Unexamined Patent Publication No. 08-335022

The present invention provides an apparatus for determining the presence or absence of a rotating member, which can determine whether or not a detachable rotating member is attached in a short time as compared with a case where an AC voltage is applied to the rotating member to determine. It is an object of the present invention to provide an image forming apparatus.

The presence / absence determination device according to claim 1 is a changing means for changing the output value of the DC voltage applied to the voltage applying member provided around the rotating member in a state where the detachable rotating member is not rotating. , The measuring means for measuring the current value of the current flowing through the voltage applying member during the period including the time when the output value is changed by the changing means, and the presence / absence of the rotating member are output from the current value measured by the measuring means. A mounting portion for mounting the rotating member equipped with a communication means, a mounting portion, and a lid portion for covering the mounting portion and the rotating member mounted on the mounting portion are further provided. The changing means is a DC voltage applied to the voltage applying member when the lid is closed and when an error occurs in communication with the communication means provided on the rotating member. The output value of the above is changed, and when an error occurs in communication with the communication means provided on the rotating member and the rotating member is present, the output means prompts the reattachment of the rotating member. Output the information for .

In the invention according to claim 1, the output means measures the current value as the presence or absence of the rotating member by the measuring means when the rotating member is present. The comparison result with the current value is output.

In the invention according to claim 1 or 2, the presence / absence determination device according to claim 3 changes the output value of the DC voltage only once.

In the invention according to claim 3, the presence / absence determination device according to claim 4 is changed so that the DC voltage becomes a predetermined output value from the state in which the DC voltage is not output.

In the invention according to claim 1 or 2, the presence / absence determination device according to claim 5 changes the output value of the DC voltage a plurality of times by the changing means.

The presence / absence determination device according to claim 6 is the invention according to claim 1 or 2, wherein the changing means is measured by the measuring means in a state where the DC voltage is applied to the voltage applying member. When the current value drops, the application of the DC voltage is stopped.

Presence determining device according to claim 7, in the invention of any one of claims 1-6, wherein the output means, wherein, when rotating member without the information for prompting the mounting of said rotary member Is output.

The image forming apparatus according to claim 8 includes a detachable unit including an image holder which is a rotating member, and a device for determining the presence or absence of the rotating member according to any one of claims 1 to 7.

The image forming apparatus according to claim 9 is the invention according to claim 8 , wherein the voltage applying member of the rotating member presence / absence determining apparatus is a charging means for charging the image holder, and a toner image is developed on the image holder. It is at least one of a developing means for transferring a toner image developed on the image holder, a transfer means for transferring a toner image developed on the image holder to an intermediate transfer belt or a recording medium, and a static eliminating means for removing charges adhering to the image holder.

According to the inventions of claims 1 and 8 , whether or not a detachable rotating member is attached can be determined in a short time as compared with the case where an AC voltage is applied to the rotating member. ..
Further, according to the invention of claim 1, it is possible to avoid unnecessary processing as compared with the case where the DC voltage applied to the rotating member is changed at an arbitrary timing.
Further, according to the invention of claim 1, it is possible to avoid rotating the rotating member in a state where the rotating member has poor contact with the mounting portion, as compared with the case where the remounting of the rotating member is not urged. can do.

According to the second aspect of the present invention, the presence or absence of the rotating member can be accurately determined as compared with the case where the current value measured by the measuring means is compared with a predetermined fixed value.

According to the third aspect of the present invention, deterioration of the rotating member can be reduced as compared with the case where the output value of the DC voltage applied to the rotating member is changed a plurality of times.

According to the invention of claim 4, the deterioration of the rotating member is further reduced as compared with the case where the DC voltage applied to the rotating member is changed from the output state to a predetermined output value. Can be done.

According to the fifth aspect of the present invention, the presence or absence of the rotating member can be accurately determined as compared with the case where the output value of the DC voltage applied to the rotating member is changed only once.

According to the invention of claim 6, deterioration of the rotating member can be further reduced as compared with the case where a DC voltage is applied to the rotating member for a predetermined period.

According to the invention of claim 7 , it is possible to avoid trying to rotate the rotating member in a state where the rotating member is not attached, as compared with the case where the rotating member is not urged to be attached.

According to the invention of claim 9 , by applying a DC voltage to an appropriate member of the image forming apparatus, it is possible to determine in a short time whether or not the image holder is attached.

It is a schematic side view which shows the whole structure of the image forming apparatus which concerns on embodiment. It is a schematic side view which shows the arrangement state of the detachable unit which concerns on embodiment. It is a schematic diagram which shows the electric connection method of the power source and the ammeter to the charging member which concerns on embodiment. It is a block diagram which shows the electrical structure of the image forming apparatus which concerns on embodiment. It is a flowchart which shows the flow of the determination process in the image forming apparatus which concerns on 1st Embodiment. It is a graph which shows an example of the time-series change of the output value of the voltage applied to a charging member, and an example of the time-series change of the current value of the current flowing through a charging member in the image forming apparatus which concerns on 1st Embodiment. It is a graph which shows an example of the current value of the current flowing through the charging member when the attachment / detachment unit is attached and the attachment / detachment unit is not attached in the image forming apparatus which concerns on 1st Embodiment. It is a graph which shows the other example of the time-series change of the output value of the voltage applied to a charging member, and another example of the time-series change of the current value of the current flowing through a charging member in the image forming apparatus which concerns on 1st Embodiment. .. It is a flowchart which shows the flow of the determination process in the image forming apparatus which concerns on 2nd Embodiment. It is a graph which shows an example of the time-series change of the output value of the voltage applied to a charging member, and an example of the time-series change of the current value of the current flowing through a charging member in the image forming apparatus which concerns on 2nd Embodiment.

[First Embodiment]

Hereinafter, the image forming apparatus according to the present embodiment will be described in detail with reference to the accompanying drawings. A case where a color indirect transfer type image forming apparatus is used as the image forming apparatus according to each embodiment will be described.

As shown in FIG. 1, inside the housing 10A of the image forming apparatus 10 according to the present embodiment, there are an image processing unit 12, an exposure apparatus 14, and yellow (Y), magenta (M), and cyan (C). , Black (K) image forming units 16Y, 16M, 16C, 16K are provided. Hereinafter, when it is not necessary to distinguish Y, M, C, and K, Y, M, C, and K are omitted. Further, the members described by omitting Y, M, C, and K refer to each of the members to which Y, M, C, and K are added.

The image processing unit 12 acquires image data to be image-formed. Further, the image processing unit 12 converts the acquired image data into gradation data of four colors of yellow (Y), magenta (M), cyan (C), and black (K).

The exposure apparatus 14 is provided in the central portion of the housing 10A, receives gradation data from the image processing unit 12, and performs image exposure with a laser beam LB. Further, each image forming unit 16 is provided above the exposure apparatus 14, and is arranged at intervals in the horizontal direction.

Each image forming unit 16 is a columnar rotating member that is rotationally driven in the A direction of FIG. 1 at a predetermined speed, and is an image holder 18Y, 18M, 18C, 18K, and an outer peripheral surface of the image holder 18. It has charging members 20Y, 20M, 20C, and 20K for primary charging. The charging member 20 is an example of charging means.

Further, each image forming unit 16 develops an electrostatic latent image formed on the outer peripheral surface of the image holder 18 charged by the exposure of the exposure apparatus 14 with a toner of a predetermined color and visualizes it as a toner image. It has developing members 22Y, 22M, 22C, and 22K. The developing member 22 is an example of developing means.

Further, each image forming unit 16 has a static elimination roll 23Y that removes electric charges adhering to the outer peripheral surfaces of the image holders 18Y, 18M, 18C, 18K in which the toner image is developed by the developing members 22Y, 22M, 22C, 22K. It has 23M, 23C, and 23K. The static elimination roll 23 is an example of static elimination means.

Further, the exposure apparatus 14 is provided with four semiconductor lasers (not shown) that are commonly configured in each image forming unit 16, and laser beams LB-Y, LB-M, and LB- are provided from these semiconductor lasers. C and LB-K are emitted according to the gradation data.

The laser beams LB-Y, LB-M, LB-C, and LB-K emitted from the semiconductor laser are irradiated to the polygon mirror 26, which is a rotating multifaceted mirror, via an f-θ lens (not shown), and the polygons are used. Deflection scanning is performed by the mirror 26. Then, the laser beams LB-Y, LB-M, LB-C, and LB-K deflected and scanned by the polygon mirror 26 are transmitted on the image holder 18 via an imaging lens (not shown) and a plurality of mirrors. The exposure point is scanned and exposed from diagonally below.

Further, since the exposure apparatus 14 scans and exposes an image onto the image holder 18 from below, toner or the like drops onto the exposure apparatus 14 from the developing member 22 or the like of each image forming unit located above. there's a possibility that. Therefore, the exposure apparatus 14 is sealed by a rectangular parallelepiped frame 28 around the exposure apparatus 14. Then, on the upper part of the frame 28, four laser beams LB-Y, LB-M, LB-C, and LB-K are transparent to be transmitted onto the image holder 18 of each image forming unit 16. Glass windows 30Y, 30M, 30C, 30K are provided.

On the other hand, as shown in FIG. 1, an endless intermediate transfer belt 32 is wound above each image forming unit 16 and is rotationally driven to rotate the intermediate transfer belt 32 in the B direction of FIG. A drive roll 40 is provided. That is, the B direction is the moving direction of the intermediate transfer belt 32. Further, above each image forming unit 16, a tension applying roll 36 for applying tension to the intermediate transfer belt 32 is provided. Further, above the intermediate transfer belt 32, a cleaning blade 38 for cleaning the outer peripheral surface of the intermediate transfer belt 32 is provided. Further, inside the circuit path of the intermediate transfer belt 32, primary transfer rolls 34Y, 34M, 34C, and 34K arranged on the opposite side of the image holder 18 with the intermediate transfer belt 32 interposed therebetween are provided. The primary transfer roll 34 is an example of transfer means.

With such a configuration, toners of each color of yellow (Y), magenta (M), cyan (C), and black (K) are sequentially formed on the image holder 18 of the image forming unit 16 by the primary transfer roll 34. The image is multiplex transferred onto the intermediate transfer belt 32.

Further, a secondary transfer roll 42 is provided on the opposite side of the drive roll 40 with the intermediate transfer belt 32 interposed therebetween. The toner images of each color of yellow (Y), magenta (M), cyan (C), and black (K) transferred multiple times on the intermediate transfer belt 32 are conveyed by the intermediate transfer belt 32. Then, the toner images of each color are sandwiched between the drive roll 40 and the secondary transfer roll 42, and are secondarily transferred to the sheet member P as a recording medium which is transported along the paper transport path 56.

Further, on the downstream side (hereinafter, simply referred to as the downstream side) of the sheet member P in the transport direction with respect to the secondary transfer roll 42, the toner image transferred to the sheet member P is fixed to the sheet member P by heat and pressure. A fixing device 44 is provided. Further, on the downstream side of the fixing device 44, a discharge roll 46 is provided which discharges the sheet member P on which the toner image is fixed to the discharge portion 48 provided in the upper part of the housing 10A of the image forming device 10.

On the other hand, on the lower side inside the housing 10A, there is a paper feed member 50 on which the sheet member P is loaded, and a paper feed roll 52 that feeds the sheet member P loaded on the paper feed member 50 to the paper transport path 56. It is provided. Further, on the downstream side of the paper feed roll 52, a separation roll 54 for separating and transporting the sheet members P one by one is provided. Further, on the downstream side of the separation roll 54, an alignment roll 58 for adjusting the transfer timing is provided.

With such a configuration, the sheet member P supplied from the paper feed member 50 is at a position where the intermediate transfer belt 32 and the secondary transfer roll 42 are in contact with each other by the alignment roll 58 which rotates at a predetermined timing (secondary transfer). It is sent to the position).

Further, the sheet member P whose image is fixed on one side by the fixing device 44 so as to be adjacent to the discharge roll 46 is not directly discharged to the discharge unit 48 by the discharge roll 46, but is transported to the double-sided transport path 62. A roll 60 is provided. As a result, the sheet member P transported along the double-sided transport path 62 is transported again to the alignment roll 58 with the front and back sides inverted, and the toner image is transferred and fixed on the back surface of the sheet member P. Is discharged to the discharge unit 48.

With the above configuration, an image is formed on the sheet member P as follows.

First, the image processing unit 12 sequentially outputs the gradation data of each color to the exposure apparatus 14. Further, the laser beams LB-Y, LB-M, LB-C, and LB-K emitted from the exposure apparatus 14 according to the gradation data are subjected to scanning exposure on the outer peripheral surface of the image holder 18 charged by the charging member 20. Then, an electrostatic latent image is formed on the outer peripheral surface of the image holder 18. The electrostatic latent image formed on the image holder 18 is made of toners of each color of yellow (Y), magenta (M), cyan (C), and black (K) by the developing members 22Y, 22M, 22C, and 22K, respectively. It is visualized as an image.

Further, the primary transfer rolls 34 arranged above each image forming unit 16 multiplex transfer the toner images of each color formed on the image holder 18 onto the orbiting intermediate transfer belt 32. ..

Further, the toner images of each color transferred on the intermediate transfer belt 32 are predetermined by the secondary transfer roll 42 from the paper feed member 50 to the paper transfer path 56 by the paper feed roll 52, the separation roll 54, and the alignment roll 58. It is secondarily transferred to the sheet member P conveyed at the same timing.

Further, the sheet member P to which the toner image is transferred is conveyed to the fixing device 44. The toner image transferred to the sheet member P is fixed to the sheet member P by the fixing device 44, and then the sheet member P is transferred to the discharge portion 48 provided on the upper portion of the housing 10A of the image forming device 10 by the discharge roll 46. Is discharged by.

Further, when forming an image on both sides of the sheet member P, the sheet member P whose image is fixed on one side by the fixing device 44 is not discharged as it is on the discharge portion 48 by the discharge roll 46, and the transport direction is switched. , It is conveyed to the double-sided transfer path 62 via the transfer roll 60. Then, by transporting the sheet member P along the double-sided transport path 62, the front and back sides of the sheet member P are reversed, and the sheet member P is transported to the alignment roll 58 again. After the toner image is transferred and fixed on the back surface of the sheet member P, the sheet member P is discharged onto the discharge unit 48 by the discharge roll 46.

In the present embodiment, as shown in FIG. 2, the image holder 18Y, the charging member 20Y, and the static elimination roll 23Y, which are rotating members, are configured as a detachable unit 21Y which is detachable from the image forming apparatus 10. There is. Further, the image holder 18M, the charging member 20M, and the static elimination roll 23m, which are rotating members, are configured as a detachable unit 21M that is detachable from the image forming apparatus 10. Further, the image holder 18C, the charging member 20C, and the static elimination roll 23C, which are rotating members, are configured as a detachable unit 21C that is detachable from the image forming apparatus 10. Further, the image holder 18K, the charging member 20K, and the static elimination roll 23K, which are rotating members, are configured as a detachable unit 21K that is detachable from the image forming apparatus 10.

On the other hand, the image forming apparatus 10 is provided with a mounting portion on which the detachable units 21Y, 21M, 21C, and 21K are mounted. Further, the image forming apparatus 10 is equipped with the detachable units 21Y, 21M, 21C, and 21K, and the openable and closable lids that cover all the attachment portions and all the attachment / detachment units 21Y, 21M, 21C, and 21K. Is provided.

The attachment / detachment unit 21 has a storage means for storing history information indicating the history of image formation such as the number of formed images, and an image formation in a state where the attachment / detachment unit 21 is attached to the attachment portion of the image forming apparatus 10. A first connection is provided for communicating with the device 10. Further, the image forming apparatus 10 is provided with a second connecting portion for communicating with the attaching / detaching unit 21 in a state where the attachment / detachment unit 21 is attached to the attachment / detachment unit 21 of the image forming apparatus 10. Then, in the state where the attachment / detachment unit 21 is attached to the attachment portion, the attachment / detachment unit 21 and the image forming apparatus 10 can communicate with each other by electrically connecting the first connection portion and the second connection portion. With the first connection portion and the second connection portion electrically connected, the history information is updated in the attachment / detachment unit 21 under the control of the image forming apparatus 10.

Further, as shown in FIG. 3, the image forming apparatus 10 is provided with a power supply 92 that applies a DC voltage to the charging member 20 included in the attachment / detachment unit 21.

Further, as shown in FIG. 3, the image forming apparatus 10 is provided with an ammeter 94 for detecting the current value of the current flowing between the charging member 20 and the image holder 18 included in the attachment / detachment unit 21.

Next, with reference to FIG. 4, the configuration of a main part of the electrical system of the image forming apparatus 10 according to the present embodiment will be described.

As shown in FIG. 4, the image forming apparatus 10 according to the present embodiment includes a CPU (Central Processing Unit) 70 that controls the overall operation of the image forming apparatus 10, and a ROM in which various programs, various parameters, and the like are stored in advance. (Read Only Memory) 72 is provided. Further, the image forming apparatus 10 includes a RAM (Random Access Memory) 74 used as a work area or the like when executing various programs by the CPU 70, and a storage unit 76 having a non-volatile memory or the like. The CPU 10 is an example of a changing means, a measuring means, and an output means.

Further, the image forming apparatus 10 includes a communication line I / F (Interface) unit 78 that communicates with an external device, and an operation display unit 80 that notifies the user of various information regarding the operating status of the image forming apparatus 10. It is composed. The operation display unit 80 includes, for example, a display button that realizes reception of operation instructions by executing a program, a touch panel type display on which various information and the like are displayed, and hardware keys such as a numeric keypad and a start button.

Further, the image forming apparatus 10 includes an image forming unit 82. The image forming unit 82 is configured to include each component that performs various processes in the above-mentioned image forming step.

Further, the image forming apparatus 10 includes a voltage control unit 84 that controls an output value of a DC voltage applied to the charging member 20 by the power supply 92.

Further, the image forming apparatus 10 is configured to include a measuring unit 86 that acquires a value detected by the ammeter 94.

Further, the image forming apparatus 10 includes a unit communication unit 88 for communicating with the attachment / detachment unit 21 mounted on the mounting portion.

Further, the image forming apparatus 10 is configured to include an open / close detection unit 90 that detects that the lid portion has changed from an open state to a closed state. The open / close detection unit 90 detects that the lid has changed from an open state to a closed state by, for example, an optical sensor that detects the open / closed state of the lid.

Then, the CPU 70, ROM 72, RAM 74, storage unit 76, communication line I / F unit 78, operation display unit 80, image forming unit 82, voltage control unit 84, measurement unit 86, unit communication unit 88, and open / close detection unit 90. Each part of is connected to each other via a bus.

With the electrical configuration described above, the image forming apparatus 10 according to the present embodiment allows the CPU 70 to access the ROM 72, the RAM 74, and the storage unit 76, and to communicate with the external device via the communication line I / F unit 78. Do each. Further, the image forming apparatus 10 acquires various information via the operation display unit 80 and displays various information on the operation display unit 80 by the CPU 70. Further, the image forming apparatus 10 forms an image by the image forming unit 82 by the CPU 70. Further, the image forming apparatus 10 performs a determination process described later by the voltage control unit 84, the measurement unit 86, the unit communication unit 88, and the open / close detection unit 90 by the CPU 70.

Here, in the present embodiment, it is determined whether or not the detachable unit 21 is attached to the image forming apparatus 10 depending on whether or not the detachable unit 21 and the image forming apparatus 10 can communicate with each other via the unit communication unit 88. do.

However, even if the attachment / detachment unit 21 is attached to the image forming apparatus 10, if the contact between the first connection portion of the attachment / detachment unit 21 and the second connection portion of the image forming apparatus 10 is unstable, the attachment / detachment unit Communication between the 21 and the image forming apparatus 10 may not be possible. In such a case, since the detachable unit 21 and the image forming apparatus 10 cannot communicate with each other, the detachable unit 21 is attached to the image forming apparatus 10 even though the detachable unit 21 is attached to the image forming apparatus 10. It will be judged that it is not installed.

Therefore, in the present embodiment, when the detachable unit 21 and the image forming apparatus 10 cannot communicate with each other, a DC voltage is applied to the charging member 20 included in the attachment / detachment unit 21 to obtain the current value of the current flowing through the charging member 20. measure. Then, depending on the measured current value, the detachable unit 21 is not attached, or the detachable unit 21 and the image forming apparatus 10 are attached to each other even though the detachable unit 21 is attached to the image forming apparatus 10. Determine if communication is not possible.

When an AC voltage is applied to the charging member 20, when the attachment / detachment unit 21 is attached to the image forming apparatus 10, the attachment / detachment unit 21 is charged as compared with the case where the attachment / detachment unit 21 is not attached to the image forming apparatus 10. The current flowing through the member 20 becomes high. Therefore, by applying an AC voltage to the charging member 20 and measuring the current value of the current flowing through the charging member 20, it is possible to determine whether or not the attachment / detachment unit 21 is mounted on the image forming apparatus 10. However, when an AC voltage is applied to the charging member 20 and the current value of the current flowing through the charging member 20 is detected, the rise of the AC voltage is slow, so that the detection takes time.

On the other hand, when a DC voltage having a predetermined output value is applied to the charging member 20, the detachable unit 21 is attached to the image forming apparatus 10 even when the detachable unit 21 is attached to the image forming apparatus 10. The current value of the current flowing through the charging member 20 does not increase as compared with the case where the current value is not set.

However, when a DC voltage is applied to the charging member 20 to change the output value of the DC voltage, if the detachable unit 21 is attached to the image forming apparatus 10, the detachable unit 21 is attached to the image forming apparatus 10. The current flowing through the charging member 20 is higher than that in the case where the charging member 20 is not used. Therefore, by applying a DC voltage to the charging member 20 and detecting the current value of the current flowing through the charging member 20, it is determined whether or not the attachment / detachment unit 21 is mounted on the image forming apparatus 10.

In this way, when a DC voltage is applied to the charging member 20 and the current value of the current flowing through the charging member 20 is detected, the time required for detection is longer than when an AC voltage is applied to the charging member 20. It will be shortened. Further, in general, when a DC voltage is used, the number of detection circuits is smaller than when an AC voltage is used, and the cost required for detection is also reduced.

Therefore, in the present embodiment, when the detachable unit 21 is mounted on the image forming apparatus 10, when the output value of the DC voltage applied to the charging member 20 is changed, the detachable unit 21 is attached to the image forming apparatus 10. It is determined whether or not the attachment / detachment unit 21 is attached to the image forming apparatus 10 by utilizing the fact that the current value of the current flowing through the charging member 20 is higher than that in the case where it is not attached. Specifically, a DC voltage is applied to the charging member 20, the output value of the applied DC voltage is changed, and the current flows through the charging member 20 for a predetermined period including the time when the output value of the DC voltage is changed. Measure the current value of the current. Then, based on the measured current value, it is determined whether or not the attachment / detachment unit 21 is attached to the image forming apparatus 10.

Further, while the image holder 18 is rotating, the image holder 18 is affected by the influence of the current value of the current flowing through the charging member 20 by the members other than the charging member 20 and the image holder 18. It is preferable to detect the current flowing through the charging member 20 in a non-rotating state. The state in which the image holder 18 is not rotated may be a state before the image holder 18 is rotated or a state in which the image holder 18 is stationary after being rotated.

As described above, in the present embodiment, the voltage applying member to which the DC voltage is applied is the charging member 20, and by applying the DC voltage to the charging member 20, the detachable unit 21 is attached to the image forming apparatus 10. The case of determining whether or not it is attached will be described, but the present invention is not limited to this. For example, the voltage applying member may be at least one of the charging member 20, the developing member 22, the static elimination roll 23, and the primary transfer roll 34, which are members close to the image holder 18. In this case, a DC voltage is applied to at least one of the charging member 20, the developing member 22, the static elimination roll 23, and the primary transfer roll 34, and the current value of the current flowing through the member to which the DC voltage is applied is measured. , It may be determined whether or not the detachable unit 21 is attached to the image forming apparatus 10.

When a DC voltage is applied to two or more of the charging member 20, the developing member 22, the static elimination roll 23, and the primary transfer roll 34, the attachment / detachment unit is determined by the integrated value, average value, etc. of the current values flowing through each member. It is preferable to determine whether or not 21 is attached to the image forming apparatus 10. Alternatively, based on the current value of the current flowing through each member, it is determined for each member whether or not the attachment / detachment unit 21 is attached to the image forming apparatus 10, and the determination results for each member are integrated to attach / detach the unit. It may be determined whether or not the unit 21 is mounted on the image forming apparatus 10.

Next, the flow of the determination process executed by the image forming apparatus 10 according to the present embodiment each time a predetermined time (for example, 1 second) elapses will be described with reference to the flowchart of FIG. In the present embodiment, the determination processing program is stored in the storage unit 76 in advance, but the present invention is not limited to this. For example, the determination processing program may be received from the external device via the communication line I / F unit 78 and stored in the storage unit 76. Further, the determination process may be executed by reading the determination processing program recorded on the recording medium such as a CD-ROM by the CD-ROM drive or the like.

In step S101, the CPU 70 determines whether or not the opening / closing signal is input from the opening / closing detection unit 90 to change from the open state to the closed state of the lid. When it is determined in step S101 that the lid portion has changed from the open state to the closed state (S101, Y), the process proceeds to step S103. If it is determined in step S101 that the lid has not changed from the open state to the closed state (S103, N), the execution of the program for this determination process ends.

In step S103, the CPU 70 attempts to communicate with the detachable unit 21 via the unit communication unit 88.

In step S105, the CPU 70 determines whether or not a communication error such as a response from the detachable unit 21 has not occurred in the communication with the detachable unit 21. If it is determined that a communication error has occurred in step S105 (S105, Y), the process proceeds to step S109. If it is determined in step S105 that no error has occurred (S105, N), the process proceeds to step S107.

In step S107, the CPU 70 determines that the attachment / detachment unit 21 is attached, and ends the execution of the program of this determination process.

In step S109, the CPU 70 controls the power supply 92 so that a DC voltage having a first output value determined in advance is applied to the charging member 20. When the first output value is set to 0V, in this step, the process proceeds to the next step without applying a DC voltage to the charging member 20.

In step S111, the CPU 70 controls so that the measurement of the current value by the ammeter 94 is started.

In step S113, the CPU 70 determines whether or not a predetermined first time (for example, 10 msec to 100 msec) has elapsed since the measurement of the current value by the ammeter 94 was started. If it is determined in step S113 that the first time has elapsed (S113, Y), the process proceeds to step S115. If it is determined in step S113 that the first time has not elapsed (S113, N), the process of this step is repeated until the first time elapses.

In step S115, the CPU 70 controls the power supply 92 so that a DC voltage having a second output value predetermined is applied to the charging member 20. The second output value may be any value as long as it is different from the first output value.

In step S117, a predetermined second time (for example, 10 msec to 100 msec) has elapsed since the CPU 70 controlled the power supply 92 so that the DC voltage of the second output value was applied to the charging member 20. Judge whether or not. If it is determined in step S117 that the second time has elapsed (S117, Y), the process proceeds to step S119. If it is determined in step S117 that the second time has not elapsed (S117, N), the process of this step is repeated until the second time elapses.

In step S119, the CPU 70 controls so that the measurement of the current value by the ammeter 94 is completed.

In step S121, the CPU 70 controls the power supply 92 so that the application of the DC voltage of the second output value to the charging member 20 is stopped.

As an example, as shown in FIG. 6, when the detachable unit 21 is mounted on the image forming apparatus 10, the output value L1 of the DC voltage applied to the charging member 20 during the first hour is the first output value. The current value L2 of the current flowing through the charging member 20 becomes almost 0. Further, when the output value L1 of the DC voltage applied to the charging member 20 is controlled to be changed from the first output value to the second output value, the current value L2 of the current flowing through the charging member 20 is high. Then, a peak appears. Further, during the second time, the output value L1 of the DC voltage applied to the charging member 20 is controlled to be the second output value, and the current value L2 of the current flowing through the charging member 20 becomes substantially 0. Then, when the output value L1 of the DC voltage applied to the charging member 20 is controlled to be changed from the second output value to the first output value, the current value L2 of the current flowing through the charging member 20 is high. Then, a peak appears.

On the other hand, when the detachable unit 21 is not attached to the image forming apparatus 10, the current flowing through the charging member 20 is current even when the output value of the DC voltage applied to the charging member 20 is controlled to be changed. The value does not increase.

In step S123, the CPU 70 determines whether or not the current value detected by the ammeter 94 is higher than a predetermined reference value. The current value referred to here is any one of an integrated value of the current values detected by the ammeter 94, an average value obtained by dividing the integrated value by the detection time, and a peak value. Further, the reference value referred to here is a reference value for determining whether or not the detachable unit 21 is attached, and is a reference value determined by the current value measured when the detachable unit 21 is attached. Is. For example, the median value of the current value measured when the detachable unit 21 is attached and the current value measured when the detachable unit 21 is not attached may be used.

As an example, as shown in FIG. 7, when the attachment / detachment unit 21 is mounted on the image forming apparatus 10, the charging member is changed when the output value of the DC voltage applied to the charging member 20 is changed as described above. The value of the current flowing through 20 becomes high. On the other hand, when the detachable unit 21 is not mounted on the image forming apparatus 10, the current value of the current flowing through the charging member 20 does not increase even if the output value of the DC voltage applied to the charging member 20 is changed. Therefore, when the detachable unit 21 is attached to the image forming apparatus 10, the current value measured by the ammeter 94 is higher than that when the detachable unit 21 is not attached to the image forming apparatus 10. ..

Therefore, the CPU 70 outputs a comparison result between the current value measured by the ammeter 94 and the current value measured when the attachment / detachment unit 21 is mounted on the image forming apparatus 10 as the presence / absence of the attachment / detachment unit 21. .. That is, when the current value measured by the ammeter 94 is higher than the reference value, it is determined that the attachment / detachment unit 21 is mounted on the image forming apparatus 10, and the current value measured by the ammeter 94 is the reference value. If it is lower than, it is determined that the detachable unit 21 is not attached to the image forming apparatus 10.

The case A in FIG. 7 represents the current value measured by the ammeter 94 when the film thickness of the image holder 18 is 40 μm, and the case B in FIG. 7 represents the film thickness of the image holder 18 of 26 μm. It represents the current value measured by the ammeter 94 in the case of. The film thickness of the image holder 18 becomes thinner due to deterioration over time.

When it is determined in step S123 that the current value measured by the ammeter 94 is higher than the reference value (S123, Y), the process proceeds to step S125. If it is determined in step S123 that the current value measured by the ammeter 94 is equal to or less than the reference value (S123, N), the process proceeds to step S127.

In step S125, the CPU 70 determines that the attachment / detachment unit 21 is mounted, but the attachment / detachment unit 21 and the image forming apparatus 2 have poor contact, and the execution of the program of this determination process ends. At this time, as an alert, the CPU 70 causes the operation display unit 80 to indicate that the detachable unit 21 and the image forming apparatus 10 have poor contact with each other, and the user is re-attached to the detachable unit 21. Encourage wearing.

In step S127, the CPU 70 determines that the detachable unit 21 is not mounted, and ends the execution of the program of this determination process. At this time, the CPU 70 displays on the operation display unit 80 that the detachable unit 21 is not attached as an alert, and prompts the user to attach the detachable unit 21.

As described above, in the present embodiment, the DC voltage is applied to the charging member 20 and the output value of the DC voltage is changed to change the output value while the image holder 18 included in the detachable unit 21 is not rotating. The current flowing through the charging member 20 is measured during the period including the changed time point, and the presence / absence of the attachment / detachment unit 21 is output from the measured current value.

As a result, for example, when the first output value is set to 0, the presence or absence of the detachable unit 21 can be determined simply by switching from the state in which the DC voltage is not applied to the charging member 20 to the state in which the DC voltage is applied.

In the present embodiment, the case where the output value of the DC voltage applied to the charging member 20 is changed once has been described, but the present invention is not limited to this, and the DC voltage may be changed a plurality of times. In this case, for example, the processes of steps S115 to S117 may be repeated a plurality of times while changing the output value of the applied DC voltage.

For example, it is assumed that the output value of the DC voltage applied to the charging member 20 is controlled to be alternately changed between the first output value and the second output value every time the third time elapses. In such a case, as shown in FIG. 8 as an example, when the detachable unit 21 is mounted on the image forming apparatus 10, the output value L3 of the DC voltage applied to the charging member 20 is the first output. While the value and the second output value are controlled to be changed alternately, the current value L4 of the current flowing through the charging member 20 becomes high.

Further, when changing the output value of the DC voltage, the output value may be changed from a low state to a high state, or from a high state to a low state. Further, by increasing the difference between the first output value and the second output value, the accuracy of determining the presence / absence of the detachable unit 21 is improved. However, considering that the image holder 18 is loaded by applying a high voltage to the charging member 20, the upper limit of the output value of the DC voltage may be set to a value equal to or less than the output value in actual use.

Further, in the present embodiment, the case where the current value of the current flowing through the charging member 20 is measured in the period before and after including the time when the output value of the DC voltage applied to the charging member 20 is changed has been described. Not limited to this. For example, the current value of the current flowing through the charging member 20 may be measured in the period after the time including the time when the output value of the DC voltage applied to the charging member 20 is changed.

[Second Embodiment]

Next, the image forming apparatus according to the second embodiment will be described.

In the first embodiment, the DC voltage of the first output value is applied to the charging member 20 in the predetermined first time, and the DC voltage of the second output value is applied to the charging member 20 in the predetermined second time. The case of applying the voltage has been described. On the other hand, in the second embodiment, when a DC voltage is applied to the charging member 20 from a state where the DC voltage is not applied to the charging member 20, and the current value of the current flowing through the charging member 20 decreases, the DC to the charging member 20 is DC. A case where the application of the voltage is stopped will be described.

As described above, it is desirable to shorten the time for applying the voltage to the charging member 20 in consideration of the fact that the image holder 18 is loaded by applying the voltage to the charging member 20. Therefore, in the present embodiment, it is said that a sufficient current value for determining whether or not the detachable unit 21 is mounted on the image forming apparatus 10 is obtained at the timing when the current value of the current flowing through the charging member 20 drops. Judgment is made, and the application of the DC voltage to the charging member 20 is terminated.

Since the configuration of the image forming apparatus according to the second embodiment is the same as that of the image forming apparatus 10 according to the first embodiment, the description of each configuration will be omitted.

Next, the flow of the determination process executed by the image forming apparatus 10 according to the present embodiment when the predetermined execution process is input will be described with reference to the flowchart of FIG. In the present embodiment, the determination processing program is stored in the storage unit 76 in advance, but the present invention is not limited to this. For example, the determination processing program may be received from the external device via the communication line I / F unit 78 and stored in the storage unit 76. Further, the determination process may be executed by reading the determination processing program recorded on the recording medium such as a CD-ROM by the CD-ROM drive or the like.

In step S201, the CPU 70 determines whether or not the opening / closing signal is input from the opening / closing detection unit 90 to change from the open state to the closed state of the lid. When it is determined in step S201 that the lid portion has changed from the open state to the closed state (S201, Y), the process proceeds to step S203. If it is determined in step S201 that the lid has not changed from the open state to the closed state (S203, Y), the execution of the program for this determination process ends.

In step S203, the CPU 70 attempts to communicate with the detachable unit 21.

In step S205, the CPU 70 determines whether or not a communication error such as a response from the detachable unit 21 has not occurred in the communication with the detachable unit 21. If it is determined that a communication error has occurred in step S205 (S205, Y), the process proceeds to step S209. If it is determined in step S205 that no error has occurred (S205, N), the process proceeds to step S207.

In step S207, the CPU 70 determines that the attachment / detachment unit 21 is attached, and ends the execution of the program of this determination process.

In step S209, the CPU 70 controls the power supply 92 so that a DC voltage having a predetermined third output value is applied to the charging member 20. The third output value may be any value as long as it is other than 0V.

In step S211 the CPU 70 controls so that the detection of the current value by the ammeter 94 is started.

In step S213, the CPU 70 determines whether or not the current value detected by the ammeter 94 has decreased. The timing for determining that the current value of the current flowing through the charging member 20 has decreased is, for example, the timing at which the pole change point of the current flowing through the charging member 20 is detected, and the current value of the current flowing through the charging member 20 of the current value. The timing at which the current value drops to a predetermined ratio (for example, 50%) with respect to the maximum value (peak value) can be mentioned.

When it is determined in step S213 that the current value has decreased (S213, Y), the process proceeds to step S215. If it is determined in step S213 that the current value has not decreased (S213, N), the process of this step is repeated until the current value decreases.

In step S215, the CPU 70 controls the power supply 92 so that the application of the DC voltage of the third output value to the charging member 20 is stopped.

In step S217, the CPU 70 controls so that the measurement of the current value by the ammeter 94 is completed.

As an example, as shown in FIG. 10, when the detachable unit 21 is mounted on the image forming apparatus 10, the output value L5 of the DC voltage applied to the charging member 20 is changed from 0 to a third output value. When controlled in this way, the current value L6 of the current flowing through the charging member 20 becomes high. Further, the output value L5 of the DC voltage applied to the charging member 20 is controlled to be 0 from the third output value at the timing when the current value of the current flowing through the charging member 20 drops.

In step S219, the CPU 70 determines whether or not the current value detected by the ammeter 94 is higher than a predetermined reference value. The current value referred to here is any one of an integrated value of the current values detected by the ammeter 94, an average value obtained by dividing the integrated value by the detection time, and a peak value. Further, the reference value referred to here is a reference value for determining whether or not the detachable unit 21 is attached, and is a reference value determined by the current value measured when the detachable unit 21 is attached. Is. For example, the median value of the current value measured when the detachable unit 21 is attached and the current value measured when the detachable unit 21 is not attached may be used.

Similar to the first embodiment, when the current value measured by the ammeter 94 is higher than the reference value, it is determined that the detachable unit 21 is mounted on the image forming apparatus 10, and the ammeter 94 measures the current value. When the current value is lower than the reference value, it is determined that the attachment / detachment unit 21 is not attached to the image forming apparatus 10.

When it is determined in step S219 that the current value measured by the ammeter 94 is higher than the reference value (S219, Y), the process proceeds to step S221. If it is determined in step S219 that the current value measured by the ammeter 94 is equal to or less than the reference value (S219, N), the process proceeds to step S223.

In step S221, the CPU 70 determines that the attachment / detachment unit 21 is mounted, but the attachment / detachment unit 21 and the image forming apparatus 2 have poor contact, and the execution of the program of this determination process ends. At this time, as an alert, the CPU 70 causes the operation display unit 80 to indicate that the detachable unit 21 and the image forming apparatus 2 have poor contact with each other, and the user is re-attached to the detachable unit 21. Encourage wearing.

In step S223, the CPU 70 determines that the detachable unit 21 is not attached, and ends the execution of the program of this determination process. At this time, the CPU 70 displays on the operation display unit 80 that the detachable unit 21 is not attached as an alert, and prompts the user to attach the detachable unit 21.

As described above, in the present embodiment, the DC voltage is applied to the charging member 20, and the application of the DC voltage to the charging member 20 is stopped at the timing when the current value measured by the ammeter 94 drops.

As a result, the time for applying the voltage to the charging member 20 is shortened, and the load applied to the image holder 18 by applying the voltage to the charging member 20 is reduced.

10 Image forming device 12 Image processing unit 14 Exposure device 16 Image forming unit 18 Image holder 20 Charging member 21 Detachable unit 22 Developing member 23 Static elimination roll 34 Primary transfer roll

Claims (9)

A changing means for changing the output value of the DC voltage applied to the voltage applying member provided around the rotating member while the detachable rotating member is not rotating.
A measuring means for measuring the current value of the current flowing through the voltage applying member during a period including the time when the output value is changed by the changing means, and a measuring means.
An output means that outputs the presence / absence of the rotating member from the current value measured by the measuring means, and
With
A mounting portion on which the rotating member provided with a communication means is mounted, and a mounting portion.
A mounting portion and a lid portion covering the rotating member mounted on the mounting portion are further provided.
The changing means applies a direct current to the voltage applying member when the lid is closed and when an error occurs in communication with the communication means provided on the rotating member. Change the output value of the voltage,
The output means is a rotation that outputs information for prompting the reattachment of the rotating member when an error occurs in communication with the communication means provided on the rotating member and the rotating member is present. A device for determining the presence or absence of members. The rotating member according to claim 1, wherein the output means outputs a comparison result of the current value with or without the rotating member and the current value measured by the measuring means when the rotating member is present. Presence / absence judgment device. The changing means is the device for determining the presence or absence of a rotating member according to claim 1 or 2, wherein the output value of the DC voltage is changed only once. The change means is the device for determining the presence or absence of a rotating member according to claim 3, wherein the DC voltage is changed from a non-output state to a predetermined output value. The changing means is the device for determining the presence or absence of a rotating member according to claim 1 or 2, wherein the output value of the DC voltage is changed a plurality of times. The changing means stops the application of the DC voltage at the timing when the current value measured by the measuring means drops while the DC voltage is applied to the voltage applying member. 2. The device for determining the presence or absence of a rotating member according to 2. The device for determining the presence or absence of a rotating member according to any one of claims 1 to 6 , wherein the output means outputs information for encouraging mounting of the rotating member when the rotating member is absent. A detachable unit including an image holder that is a rotating member,
The device for determining the presence or absence of a rotating member according to any one of claims 1 to 7.
An image forming apparatus having. The voltage applying member of the rotating member presence / absence determining device includes a charging means for charging the image holder, a developing means for developing a toner image on the image holder, and an intermediate transfer belt for developing a toner image on the image holder. The image forming apparatus according to claim 8, which is at least one of a transfer means for transferring to a recording medium and a static elimination means for removing charges adhering to the image holder.

Images