JPH09179460A - Electrified body life detecting device, process unit with it, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect the life of an electrified body with a contact electrifying member applied with a superimposing voltage containing an AC bias component. SOLUTION: The time when a superimposing voltage containing an AC bias component is applied to an electrifying roller 2 is integrated. Only the time when the damage of a photoreceptor 1 occurs most remarkably is integrated, and this integrated value and the life information set in advance are compared by a comparison section 25. The deterioration degree of the photoreceptor 1 can be detected based on the compared result, and the life of the photoreceptor 1 can be accurately grasped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic copying machine or a printer, and more particularly to a charged object life detecting device for detecting the life of the charged object. The present invention relates to a provided process unit and image forming apparatus.

[0002]

2. Description of the Related Art In a conventional electrophotographic image forming apparatus, as an example of an apparatus for detecting the life of a photosensitive drum as an object to be charged, an apparatus for detecting the life of an object to be charged which accumulates the number of prints (copies) is taken as an example. There is. Although this charged object life detecting device is the simplest, it is the same even when the wear area of the surface of the photosensitive drum is different, such as when the size of copying is different, for example, when forming an image of A4 size or A3 size. Since it is counted as one copy, the life detection accuracy is not good, and the rotation time of the photosensitive drum per one is different depending on how many copies are made per job. Therefore, the life detection accuracy is not good. There are drawbacks.

Further, as an apparatus for detecting the life of a member to be charged, there is a device for detecting the charge amount by a surface potential sensor, as disclosed in Japanese Patent Laid-Open No. 4-51259. That is, since the charged object life detecting device actually detects a decrease in the charging potential of the photosensitive drum or a decrease in latent image contrast by the surface potential sensor, the charged object life detecting device for accumulating the number of prints is used. By comparison, it is possible to detect the lifespan with high accuracy by reflecting the state of the output image.

However, the charged object life detecting device of this example requires a surface potential sensor and an electric circuit for processing the output thereof, resulting in a high cost. Moreover, since information on the photosensitive drum corresponding to the position where the surface potential sensor is provided is used as the life detection information, it is not always possible to reliably detect a partial defect of the photosensitive drum. Considering instability such as change over time, there is a problem that it is not possible to always accurately detect the life.

Further, as a charged object life detecting device, as shown in Japanese Patent Laid-Open No. 5-188674, a device for integrating the number of rotations of the photosensitive drum and a time for rotating the photosensitive drum are integrated instead of integrating the number of copies. There is something. These charged object life detectors have a large number of rotations when the paper size is large, and have a small number of rotations when the paper size is small. Therefore, compared with the charged object life detector that accumulates the number of copies, The life detection error due to the difference in paper size is reduced. Further, since the number of rotations (rotation time) of the drum is directly added regardless of the number of copies per job, the accuracy of life detection is improved.

Further, as an apparatus for detecting the life of a member to be charged, as shown in Japanese Patent Application Laid-Open No. 4-98265, the number of rotations of the photosensitive drum is set only when the transfer charger is operating and the actual image formation is performed. It is disclosed that the life can be detected more accurately by integrating the above.

Further, as disclosed in Japanese Patent Laid-Open No. 6-180518, the drum rotation speed while charging is being performed and the drum rotation speed while the cleaning member is in contact with each other are summed up to obtain respective values. In some cases, the life is judged based on the set value (life).

On the other hand, Japanese Patent Laid-Open Publication No. Hei 5 (1999) -19995 discloses a charged object life detecting device that informs beforehand of the replacement timing of a print cartridge composed of a cleaning member and a charged member.
There is one disclosed in Japanese Patent No. 333626. This print cartridge is provided with a storage element, and the storage element integrates the number of copies to stop the image forming apparatus from becoming unusable at the end of the guaranteed life of the member to be charged. It is designed to perform the replacement display operation based on the life of the body, and to prompt the replacement preparation by indicating that the replacement time is approaching until the guaranteed life, and even if it is used continuously. This indicates that it is almost time to stop the image forming apparatus.

As another device, there is a device for displaying a message prompting the replacement of the print cartridge based on the capacity in the toner storage portion. That is, this device integrates the on-time of the drive motor for toner replenishment, and stops the device at the integrated time at which the replacement time is expected to be reached earliest under the worst conditions in consideration of various variations. . In this case as well, a display prompting replacement at a certain accumulated time until the device is stopped and a display indicating that it is near the time to stop the device at the next accumulated time further advanced are displayed. Further, the display operation based on the life of the charged body and the cartridge replacement display operation based on the capacity of the toner storage portion are usually displayed with priority given to the number of copies, but in the unlikely event that the image density is abnormally large. When the toner is frequently replenished and it is time to replace the cartridge based on the capacity of the toner storage unit earlier than the guaranteed number of charged bodies, the cartridge replacement display operation is activated.

In addition, when the print cartridge is replaced, the total energizing time of the primary charger of the image forming apparatus is set to the CPU.
By collectively writing to the storage element (EEPROM) with, by writing and saving the total energization time of the primary charger thereafter, by collecting and analyzing the storage element (EEPROM) of the used print cartridge, It is possible to accurately ascertain the total number of revolutions of the member to be charged (photosensitive drum) and the discharge time of the corotron in the image forming apparatus using this used print cartridge. Information is collected for the device. Specifically, it is possible to grasp the number of operation cycles of the charged body of the image forming apparatus when the print cartridge is replaced, the ozone filter replacement timing, the prediction of wear data of the charged body, and the like.

However, since the above-mentioned charged object life detecting device determines the life depending on the number of copies, the accuracy of life prediction cannot be improved.

On the other hand, in a recent primary charging device, a contact charging device has come to be used in place of the corona charging device which has been used conventionally. The contact charging device has advantages such as a lower applied bias than the conventional corona charging device, a very small amount of ozone generation, and a small number of parts constituting the charging device.

Further, the contact charging device is roughly classified into a brush charging device and a roller charging device depending on a member used for charging a member to be charged. Among them, the brush charging device is
There is a problem that the tip of the bristle falls due to the brush as the charging member coming into contact with the body to be charged for a long period of time. On the other hand, the roller charging device must adjust the resistance of the roller as a charging member in order to obtain uniform charging, prevent the drum from being contaminated by the bleeding of the rubber forming the roller, and ensure uniform charging. There are problems such as severe restrictions on the roller shape and surface roughness in order to obtain the charge.

As the voltage applied to the charging member,
There are DC charging in which only DC bias is applied and AC charging in which AC bias is superimposed on DC bias. In general, A
C charging can be more uniformly charged than DC charging.

Further, in AC charging, a roller is used as a charging member, and a DC bias is superposed on an applied bias with an AC voltage which is at least twice the discharge start voltage (Japanese Patent Laid-Open No. 63-63).
No. 149669, Japanese Patent Application Laid-Open No. 1-267667), a method in which a conductive brush is used as a charging member and a DC voltage is superposed on an AC voltage whose applied bias is not more than twice the discharge start voltage (Japanese Patent Application Laid-Open No. 6-130732). and so on.

[0016]

However, the conventional contact charging device causes more damage to the charged body than the corona charging device, and the tendency is remarkable especially in the organic photosensitive drum. Further, the higher the voltage applied to the contact charging device, the greater the damage to the photosensitive drum, and the damage when the AC voltage is applied (particularly the scraped amount of the organic photosensitive drum) is the same as the peak-to-peak voltage of the AC voltage. D
There is a problem that the damage is several times as large as when only the C voltage is applied.

Especially, when an AC voltage having a peak-to-peak voltage which is more than twice the discharge starting voltage is applied, this phenomenon is remarkable. However, even if the AC voltage is less than twice the discharge starting voltage, the DC voltage is still generated. A few times more damage will occur than with No.

Therefore, in the image forming apparatus using the contact charging member for applying the AC voltage, when the life of the charged body is to be detected, the life detecting apparatus using the number of rotations of the drum accurately measures the life of the charged body. It becomes difficult to predict, and no warning is given even if the charged body has reached the end of its life and an image defect has occurred, or there is a problem such as issuing a warning even though the charged body has not reached the end of its life. there were.

The present invention has been made in order to solve the above problems, and uses a contact charging member to which an AC voltage is applied so that the life of a charged member can be accurately detected. An object is to provide a body life detecting device, a process unit including the same, and an image forming apparatus.

Another object of the present invention is to detect that a charged object is about to be replaced due to its life, so that the charged object can be replaced immediately when it reaches the end of its life. An object of the present invention is to provide an apparatus for detecting life of a charged body, which stops the image forming operation when the charged body reaches the end of its life, and prevents damage to the charged body, a process unit including the same, and an image forming apparatus. And

Still another object of the present invention is to provide a process unit in which the charged body can be easily replaced when the charged body reaches the end of its life.

[0022]

In order to achieve the above object, the first invention of the charged object life detecting device according to the present invention is a contact charging member to which a voltage including an AC bias component is applied and the contact charging member. Has a body to be contacted with the contact charging member,
An AC output for detecting the life of the charged body charged based on the voltage applied to the contact charging member, the AC output detecting that the AC bias component is applied to the contact charging member. Instructing means, integrating means for integrating the application time of the AC bias component instructed by the alternating current output instructing means, and comparing means for comparing the integrated value integrated by the integrating means with predetermined life information of the body to be charged. And an informing unit for informing whether or not the charged body is at the end of its life based on the comparison result of the comparing unit.

A second aspect of the present invention has a contact charging member to which a voltage including an AC bias component is applied, and a member to be charged with which the contact charging member contacts, and the charging is performed based on the voltage applied to the contact charging member. To detect the life of the body to be charged, which is instructed by the AC output instruction means for detecting that the AC bias component is applied to the contact charging member. An integrating means for integrating the application time of the AC bias component is compared with an integrated value integrated by the integrating means and predetermined life advance notice information for prompting replacement preparation of the charged body and life information of the charged body. The life of the member to be charged is predicted when the comparison means and the integrated value integrated by the integration means on the basis of the comparison result of the comparison means are greater than or equal to the life notification information and less than or equal to the life information. And, characterized by comprising a determination means for inhibiting an image forming operation when further exceeds the lifetime information.

A third aspect of the present invention has a contact charging member to which a voltage including an AC bias component is applied and an object to be contacted with the contact charging member, and the charging is performed based on the voltage applied to the contact charging member. To detect the life of the body to be charged, which is instructed by the AC output instruction means for detecting that the AC bias component is applied to the contact charging member. An accumulating unit that accumulates the application time of the AC bias component, a storage element that sequentially updates and stores the integrated value accumulated by the accumulating unit, and an integrated value that is updated and stored in the storage element is read out, It is characterized by further comprising: comparing means for comparing with the life information, and notifying means for notifying whether or not the charged body is at the end of life based on the comparison result of the comparing means.

According to a fourth aspect of the present invention, the storage element is incorporated in a process unit having at least a contact charging member to which a voltage including at least an AC bias component is applied, and a member to be contacted with the contact charging member, and The process unit is detachably attached to the main body of the image forming apparatus.

According to a fifth aspect of the present invention, the process unit has at least the storage element, a contact charging member to which a voltage including an AC bias component is applied, and a body to be charged with which the contact charging member contacts. It is detachably attached to the main body of the image forming apparatus provided with the charged object life detecting device according to claim 3 other than the memory element.

According to a sixth aspect of the present invention, the image forming apparatus is the first aspect.
4. A charged object life detecting device according to claim 3, a charged member uniformly charged by a contact charging member to which a voltage including an AC bias component is applied, and an electrostatic latent image on the charged member. An exposing means for forming a toner image, a developing means for developing the electrostatic latent image formed on the charged body to form a toner image, and a transfer means for transferring the toner image formed on the charged body to a transfer material. It is equipped with.

[Operation] Based on the above configuration, in the first invention, the time during which the voltage including the AC bias component instructed by the AC output instructing means is applied to the contact charging member is integrated. As a result, only when the damage to the member to be charged occurs most prominently, the integrated value is compared with preset life information to grasp the accurate degree of deterioration of the member to be charged.

In the second invention, in addition to the above-mentioned function, a message prompting the user to replace the charged object before it reaches the end of its life is displayed to detect that the charged object is near the end of its life and is about to be replaced. As a result, a new member to be charged can be prepared in advance, and the member to be charged can be immediately replaced at the end of its life, and the down time of the image forming apparatus can be shortened to improve the working efficiency. .

Further, when the charged body reaches the end of its life, the image forming apparatus is stopped so that the main body of the image forming apparatus is not damaged even if the image forming apparatus body is used without regard to the display prompting replacement. did.

In the third invention, the integrated value obtained by integrating the application time of the AC bias component is sequentially updated and stored in the storage element. As a result, the application time of the charged body when the damage to the charged body occurs most significantly is integrated, and the updated and stored integrated value is compared with the preset life information to obtain an accurate coverage. The degree of deterioration of the charged body was grasped.

Further, in the fourth aspect of the present invention, the storage element is provided in the process unit to record the degree of deterioration of the member to be charged, so that the old and new process units can be reliably identified. This makes it possible to prevent a mistake in replacing the process unit.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. <First Embodiment> FIG. 1 is a schematic sectional view showing the arrangement of an image forming apparatus according to the first embodiment of the present invention.

In FIG. 1, the image forming apparatus includes a drum type electrophotographic photosensitive member (hereinafter, simply referred to as “photosensitive member”) 1 as a member to be charged, a charging roller 2 as a contact charging member, a developing device 7, A process cartridge 17 in which the cleaning device 14 and the like are incorporated, and a transfer roller 13 provided around the process cartridge 17.
, Fixing device 15, laser scanner 4 and mirror 6
And an optical system having

The image forming process of this image forming apparatus will be described below.

The photosensitive member 1 has an outer diameter of 3 in which a photoconductive photosensitive layer 1a is laminated on the surface of a conductive substrate 1b made of aluminum.
0mm photosensitive drum, 100mm / sec in the direction of arrow A in the figure
It is driven to rotate at the peripheral speed (process speed).

The photoconductor 1 is uniformly charged to a negative polarity by the charging roller 2 and then output from the laser scanner 4 corresponding to the time series electric digital image signal of the image information sent from the video controller (not shown). Scanning exposure having a resolution of 600 dpi is performed by laser exposure 5 that is performed, and a mirror 6 that is installed in the main body of the image forming apparatus.
An electrostatic latent image is formed on the surface via.

The electrostatic latent image on the photoconductor 1 is reversely developed by the toner 8 carried on the developing sleeve 11 in the developing device 7 to be visualized (toner image).

Then, the toner image is transferred onto the transfer paper P by the transfer roller 13. The transfer paper P on which the toner image has been transferred is separated from the photoconductor 1 and introduced into the fixing device 15, where the toner image is fixed. The transfer paper P on which the toner image is fixed is ejected from the main body of the image forming apparatus. Photoreceptor 1 to which residual toner adheres after the transfer process
Are cleaned by the cleaning device 14, and the charging process is performed so that the cleaned surface is repeatedly used for image formation.

By the way, the developing device 7 adopts a non-contact developing method, and is rotated in the direction of arrow B while carrying the toner 8 and the toner container 3 for storing the toner 8 and conveyed to the photoconductor 1. The developing sleeve 11 is a rotatable toner carrier and the magnetic field generating means 10 fixed in the developing sleeve 11.

The developing sleeve 11 is connected to a power supply 16 for applying a voltage in which an AC bias component (AC bias component) is superimposed on a DC bias component (DC bias component). The power supply 16 serves as an AC bias component. The peak-to-peak voltage is 1200V square wave, -500V DC
A voltage with a bias component superimposed is generated.

The doctor blade 9 for controlling the layer thickness of the toner 8 applied to the developing sleeve 11 is urethane rubber, and its hardness is JIS-A67 ° and the thickness is 1.1 mm. When a weight voltage is applied to the developing sleeve 11, a thin layer of the toner 8 is applied on the developing sleeve 11. Then, the toner 8 adheres to the photoconductor 1 at the portion where the developing sleeve 11 and the photoconductor 1 face each other, and the electrostatic latent image is developed. In this case, the toner 8 is a magnetic one-component toner, and the toner 8 is stored in the toner storage chamber 3.

On the other hand, the charging roller 2 has a two-layer structure in which a sponge layer 2b and a surface layer 2c are laminated on a cored bar 2a. The charging roller 2 has an outer diameter of 12 mm, a core metal 2a has a diameter of 6 mm, and a length of about 220 mm. Further, both ends of the cored bar 2a are pressed toward the photoconductor 1 by a force of 500 gf, respectively, are rotated in the direction of arrow C in the drawing, and are in contact with the photoconductor 1 with a nip of about 1.5 mm. . The charging roller 2 is not driven, and is driven to rotate with respect to the photoconductor 1.

In addition, the charging roller 2 is
It is connected to the next bias application power source 12. The primary bias application power supply 12 has a peak-to-peak voltage of 1600 V and a sine wave AC bias component of frequency 1200 Hz of -700 V.
It is possible to apply a voltage in which the voltage of the DC bias component of By applying this voltage to the charging roller 2,
The surface of the photoconductor 1 is uniformly charged to about -680V.

Next, a device for detecting the life of the photoconductor, which is a feature of the present invention, will be described.

As shown in FIG. 1, the primary bias application power source 12 includes a primary DC voltage output instruction section (hereinafter, simply referred to as "DC instruction section") 20 and a primary A output instruction section, which is a primary A voltage output section.
C voltage output instruction section (hereinafter simply referred to as "AC instruction section")
21 is connected. And these direct current indicator 2
0 and the DC bias component of the primary bias application power source 12 applied to the charging roller 2 by the AC instruction unit 21 and A
The C bias component is controlled independently. Further, the AC instruction unit 21 is connected to an AC application detection integration unit (AC application detection integration unit) 22 as integration means, and detects whether an AC voltage (AC voltage) is applied to the charging roller 2. At the same time, the application time of the AC voltage is integrated. The AC application detection integration unit 22 is connected to the AC application time storage unit (AC application time storage unit) 23, reads the integrated value of the AC application time from the AC application time storage unit 23 for each job,
The application time of the AC bias component applied to the charging roller 2 during the immediately preceding one job is added to this integrated value to update the integrated value stored in the AC application time storage unit 23.

This work is repeated for each job of the copying operation. After the copying operation is finished, the AC application time storage unit 23
When the update of the integrated value stored in is completed, the comparing section (comparing means) 25 reads the preset life information (AC application integrated time) from the photoconductor life information storage section 24, and the AC application time storage section. From 23, the updated integrated value is read, and the magnitude relationship between the two is compared. The result of the comparison is judged by the judging means, and when the updated integrated value is larger than the life information, a signal is sent to the notifying section 26 which is the notifying means to display on the display that the photoconductor 1 has reached the end of life. Or give a warning with a speaker.

Next, the image forming sequence when two copies are made will be described with reference to FIG.

When the main motor (not shown) receives a print signal, the main motor starts to rotate, and the pre-multi-rotation time (T ₂ ), the image forming time (T ₁ × 2), the paper interval time (T ₃ ) and the post-rotation time. Rotate for the total time (T ₄ ). The AC bias component and the DC bias component of the primary bias applying power source 12 are applied at the same time at the start of forming an image on the first sheet, but thereafter, the direct current instruction unit 20 and the alternating current instruction unit 21.
Are controlled independently as appropriate.

That is, during the time (T ₃ ) between the first copy and the second copy (so-called paper interval), the AC bias component is turned off (T ₃ -T ₆ ) (AC voltage is The application time is short), and the damage to the photoconductor 1 is minimized. The application time of the AC bias component is a time corresponding to the required image formation time (T ₁ ) plus the length (T ₆ ) of one round of the photoreceptor 1 before image formation. On the other hand, the transfer bias application time is slightly longer than the required image forming time (T ₁ ) (T ₁ ′). The application time (T ₅ ) of the DC bias component of the primary bias application power supply 12 is longer than the application time (T ₆ + T ₁ ) of the AC bias component. This is applied for the purpose of preventing the adverse effect that the surface potential of the photoconductor 1 is made negative and the photoconductor 1 is charged by the positive charge of the transfer roller 13.

As shown in FIG. 2, the motor rotation time, the DC bias component application time (T ₅ ), the AC bias component application time (T ₆ + T ₁ ), and the transfer bias application time (T
₁ ') are different.

As a result of studying damage to the photoconductor 1 in each state of the sequence, particularly abrasion of the photosensitive layer 1a of the photoconductor 1 (hereinafter referred to as "drum abrasion"), the drum in a state where no bias is applied is examined. When the scraping is 1, the scraping of the drum under the condition that the DC bias component is applied is 2-3, and the scraping of the drum under the condition that the AC bias component is applied is 6-8. is there. This result was obtained as a result of an examination using an OPC photosensitive member having a photosensitive layer 1a using a polycarbonate resin as a main binder as the photosensitive member 1.

From the above examination results, assuming that the life of the photosensitive member 1 is determined by the drum abrasion, the drum abrasion amount is estimated by integrating the AC bias component application time (T ₆ + T ₁ ). It is possible to accurately detect the life of the photoconductor 1. Since the conventional photoreceptor life detection device is an image forming apparatus using a corona charger in which the drum rotation time and the drum abrasion amount are approximately proportional to each other, the drum rotation speed or the drum rotation time is integrated to obtain the photoreceptor. However, in the contact charging device which uses the contact charging member as the primary charging means and applies the AC bias component, the drum rotation time and the drum abrasion amount are not proportional and the accuracy is It is impossible to detect the life of the photoconductor 1 with good quality.

The transfer bias application time (T ₁ ')
By integrating the, can be inferred the application time of some AC bias component (T ₆ + T _1), AC bias component of the application time (T ₆ + T ₁₎ is an image formation time (T ₁₎ Length of one round of photoreceptor 1 before image formation (T ₆ ).
Is applied, the transfer bias application time (T ₁ ′) (≈T ₁ ) is different from the transfer bias application time (T ₆ ), by the length of one round of the photoconductor 1 before image formation (T ₆ ). However, this difference deteriorates the life detection accuracy.

In the present embodiment, the AC application detection integration unit 2
By detecting the application time of the AC bias voltage in 2 and updating the AC application time storage unit 23 to the latest integrated value, the drum abrasion amount of the photoconductor 1 can be estimated and accurate life detection can be performed. That is, the integrated value of the AC application time is read from the AC application time storage unit 23 for each job, and the application time of the AC bias component applied to the charging roller 2 during the immediately preceding job is added to this integrated value, The integrated value stored in the AC application time storage unit 23 is updated. As a result, it becomes possible to accurately detect the life of the photoconductor 1.

Although the sponge charging roller is used as the contact charging member in the present embodiment, it may be a solid rubber charging roller. In addition, the contact charging member,
Not limited to the charging roller, the blade shape,
It may be a brush shape or a brush roller.

In this embodiment, the case where the AC applied voltage having the peak-to-peak voltage which is more than twice the discharge starting voltage is used is explained.
Even when the C applied voltage is used, the drum abrasion is about 1.5 to 2 times compared to the state in which the DC bias component is applied. Therefore, it is accurate to detect the life by integrating the AC charging time. It is effective enough to raise. <Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIG.

Since the structure of the present embodiment is the same as that of the first embodiment shown in FIG. 1, this embodiment will be described with reference to FIGS. 1 and 3.

FIG. 3 shows a flowchart of the life display after updating the integrated value of the AC bias application time.

In the present embodiment, the photoconductor life information storage unit 24 stores the time for determining the life of the photoconductor 1,
When the life of the photoconductor 1 is approaching, it is set in two stages: a life time advance notice (lifetime advance notice information) T ₇ and an actual life time of the photoconductor 1 (lifetime information) T ₈ that prompts the user to prepare for replacement. ing. Note that the life advance time T ₇ <the life time T ₈ .

In the charging roller 2, the AC bias component and the DC bias component from the primary bias applying power source 12 are independently controlled by the AC instructing section 21 and the DC instructing section 20,
Applied. The AC instruction unit 21 is an AC application detection integration unit 22.
The time when the AC bias component is applied is detected and integrated. The AC application detection integration unit 22 is
The AC bias time is connected to the AC application time storage unit 23, the integrated value of the AC application time is read from the AC application time storage unit 23 for each job, and the AC bias applied to the charging roller 2 during the immediately preceding job is read from the integrated value. Add the component application time,
The integrated value stored in the AC application time storage unit 23 is updated (ST1).

This work is repeated for each job of the copying operation. One job is completed, and the AC application time storage unit 23
When the update of the integrated value stored in is completed, the updated integrated value T ₀ is read into the comparison section 25 from the AC application time storage section 23 (ST2), and the life advance notice set in advance from the photoconductor life information storage section 24 is set. Information of time T ₇ and life time T ₈ is read (ST3).

Then, the result of comparing (ST4) the integrated value T ₀ and the life advance notice time T ₇ is judged by the judging means.
That is, when the updated integrated value T ₀ is smaller than the life time T ₇ , the normal copying sequence is resumed and the photoconductor 1
The life information of is not displayed (ST5). Result of the comparison between the integrated value T ₀ and lifetime warning time T _7, if T ₀ ≧ T _7,
In the next step, the integrated value T ₀ and the life time T ₈ are compared (ST6). In the judgment of step ST6, T
_{If 0} <T ₈ , the life of the photoconductor 1 is approaching, and an instruction is issued to prompt the preparation for replacement (ST7). Also, T ₀
If ≧ T ₈ , the notification unit 26 is informed that the photoconductor 1 has reached the end of its life, and an instruction to replace the photoconductor 1 is issued.
The next copying operation is prohibited (ST8). When it is confirmed that the photoconductor 1 has been newly replaced, the copying operation is permitted again.

In the present embodiment, the time for determining the life of the photoconductor 1 is set in two steps, but it is set more finely than that and detailed life information of the photoconductor 1 is displayed. It goes without saying that you can do so. <Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIG.

FIG. 4 is a schematic sectional view of an image forming apparatus showing a third embodiment of the present invention.

In this embodiment, the photoconductor 1, the charging roller 2, and the cleaning device 14 are integrated into a drum unit 27, and the developing device 7 is a separate unit. A storage element 28 (E
EPROM) is provided. Further, a connection terminal (not shown) is provided on the container of the drum unit 27 so as to communicate with the control unit of the image forming apparatus main body.

As shown in FIG. 4, the AC bias component and the DC bias component from the primary bias applying power source 12 are independently controlled and applied to the charging roller 2 by the AC indicating section 21 and the DC indicating section 20. . The alternating-current instruction unit 21 is connected to the alternating-current application detection integration unit 22 and detects and integrates the time during which the AC bias component is applied. The AC application detection integration unit 22 is the EEPROM 2 in the drum unit 27.
The integrated value stored in the EEPROM 28 is stored in the EEPROM 28 by reading the integrated value from the EEPROM 28 for each job, adding the application time of the AC bias component applied to the charging roller 2 during the immediately preceding one job to the integrated value. Update the value. This work is repeated for each job of the copying operation. When one job is completed and the update of the integrated value stored in the EEPROM 28 is completed, the comparison unit 25 causes the life information (AC) preset in the photoreceptor life information storage unit 24 to be set.
The integrated voltage application time) is read and the EEPROM 28
The updated integrated value is read from and the magnitude relationship between the two is compared.

As a result of the comparison, if the updated integrated value is larger than the life information, a signal is sent to the notification unit 26 to warn or display that the photoconductor 1 has reached the life.

Since the EEPROM 28 is provided in the drum unit 27, the E of each drum unit 27 is
Since the AC application accumulated time stored in each EPROM 28 is different, each drum unit 27 can be easily identified. That is, even if the old drum unit 27 is mistakenly mounted when the drum unit 27 is replaced with a new drum unit 27, it is possible to determine whether the photoconductor 1 is deteriorated or new without a special identification means. You can prevent mistakes in replacement.

[0070]

As described above, the first aspect of the present application
According to the invention of claim 1, when a voltage superposed with an AC bias component is applied to the contact charging member and the contact charging member is brought into contact with the member to be charged to perform charging, the AC application time is integrated, and the integrated value and the life Since the life of the member to be charged is detected by comparing it with the information, the life of the member to be charged can be accurately detected.

According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, it is possible to detect that the time to replace the charged body is approaching. Therefore, a new charged body is prepared in advance. The image forming operation is stopped when the charged body reaches the end of its life, and the image forming operation is stopped when the charged body reaches the end of its life. Therefore, the main body of the image forming apparatus can be prevented from being damaged.

Further, according to the third aspect of the invention, the integrated value obtained by integrating the application time of the AC bias component when the damage to the member to be charged most significantly occurs is updated and stored in the storage element, and the integrated value and the integrated value are stored in advance. Since the set life information is compared, it is possible to accurately grasp the degree of deterioration of the body to be charged.

Further, according to the fourth aspect of the present invention, the memory element is provided in the process unit including the member to be charged, and the memory element is updated and stored while accumulating the application time of the AC bias component. The process unit can be easily identified, and the mistake of replacing the process unit can be prevented.

Further, according to the fifth aspect of the invention, since the memory element, the body to be charged and the contact charging member are provided in the process unit, the exchange of the body to be charged can be facilitated.

[Brief description of the drawings]

FIG. 1 is a schematic configuration sectional view showing a first embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a diagram showing an image forming sequence of the above.

FIG. 3 is a life detection flowchart showing a second embodiment of the image forming apparatus according to the present invention.

FIG. 4 is a schematic sectional view showing a third embodiment of the image forming apparatus according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Charged object (photoreceptor) 2 Contact charging member (charging roller) 12 Primary bias application power source 20 Primary DC voltage output instruction section 21 AC output instruction means (Primary AC voltage output instruction section) 22 Integration means (AC application) Detection integration part) 23 AC application time storage part 24 Photoconductor life information storage part 25 Comparison means (comparison part) 26 Notification means (report part) 27 Drum unit 28 Storage element (EEPROM)

Front page continuation (72) Inventor Yasuyuki Ishii 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (6)

[Claims] 1. A contact charging member to which a voltage including an AC bias component is applied, and a member to be contacted with the contact charging member, the member being charged based on the voltage applied to the contact charging member. In a charged object life detecting device for detecting the life of a charged body, an AC output instructing means for detecting that the AC bias component is applied to the contact charging member, and an AC instructed by the AC output instructing means Integrating means for integrating the application time of the bias component, comparing means for comparing the integrated value integrated by the integrating means with predetermined life information of the charged body, and the charged body based on the comparison result of the comparing means. A charged object life detecting device comprising: a notifying unit for notifying whether or not the body is at the end of life. 2. A contact charging member to which a voltage including an AC bias component is applied, and a member to be contacted with the contact charging member, wherein the member to be charged is charged based on the voltage applied to the contact charging member. In a charged object life detecting device configured to detect the life of a charged body, an AC output instructing unit that detects that the AC bias component is applied to the contact charging member, and the AC output instructing unit instructed by the AC output instructing unit Comparing means for accumulating the application time of the AC bias component, comparing the integrated value accumulated by the accumulating means with predetermined life advance notice information for prompting the replacement preparation of the body to be charged and life information of the body to be charged Means, and the integrated value integrated by the integrating means based on the comparison result of the comparing means is greater than or equal to the life notice information and less than or equal to the life information, the life of the body to be charged. The foretold, further wherein and a determination means for inhibiting an image forming operation when exceeding the lifetime information, the charged member lifetime detecting device, characterized in that. 3. A contact charging member to which a voltage including an AC bias component is applied, and a member to be contacted with the contact charging member, wherein the member to be charged is charged based on the voltage applied to the contact charging member. In a charged object life detecting device for detecting the life of a charged body, an AC output instructing means for detecting application of the AC bias component to the contact charging member, and an AC instructed by the AC output instructing means Integrating means for integrating the application time of the bias component, a storage element for sequentially updating and storing the integrated value integrated by the integrating means, and reading the integrated value updated and stored in the storage element to determine a predetermined life of the charged body. Charging means for comparing with information, and reporting means for reporting whether or not the charged body is at the end of its life based on the comparison result of the comparing means. Body life detection device. 4. The storage element is built in a process unit having at least a contact charging member to which a voltage including at least an AC bias component is applied, and a member to be contacted with the contact charging member, and The charged object life detection device according to claim 3, wherein the device is detachably attached to the main body of the image forming apparatus. 5. The memory device according to claim 3, further comprising at least the memory element, a contact charging member to which a voltage including an AC bias component is applied, and a member to be charged with which the contact charging member contacts. The process unit, which is detachably attached to the main body of the image forming apparatus including the charged object life detection device. 6. The charged object life detecting device according to claim 1, a charged member uniformly charged by a contact charging member to which a voltage including an AC bias component is applied, An exposing unit that forms an electrostatic latent image on the charged body; a developing unit that develops the electrostatic latent image formed on the charged body to form a toner image; and a toner image formed on the charged body. An image forming apparatus comprising: a transfer unit configured to transfer to a transfer material.