JP2002072787A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic image forming apparatus which can properly predict the life of a photosensitive drum. SOLUTION: This apparatus is equipped with a rotation time counter TC which measures the rotation time of the photosensitive drum 91 and a means which counts sheets of recording paper used for image formation. When the rotation time of the photosensitive drum 91 exceeds a specific time or when the number of sheets of recording paper used for the image formation exceeds a specific number, the life of the photosensitive drum 91 is predicted according to the rotation time or the number of sheets of recording paper respectively and a user is notified of the replacement period of the photosensitive drum 91.

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 using an electrophotographic system, and more particularly to an image forming apparatus capable of appropriately estimating the life of a photosensitive drum.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus, toner is selectively attracted to an electrostatic latent image formed on a photosensitive drum, developed as a toner visible image, and transferred to a sheet of paper. And heat and press to fix on paper. By repeatedly performing image formation in this manner, the photosensitive layer formed on the surface of the photosensitive drum is deteriorated due to abrasion, and as a result, an image defect occurs. In order to prevent such an image defect, it is necessary to determine the life of the photosensitive drum based on the use condition and replace it at an appropriate time.

In a conventional image forming apparatus, the number of recording sheets used for image formation is counted, and when the counted number exceeds a predetermined value, it is determined that the photosensitive drum has reached the end of its life.

[0004]

Incidentally, the image forming apparatus is provided with a cleaning means such as a charging brush for removing toner remaining on the surface of the photoreceptor drum. In many cases, a plurality of print modes are prepared. That is, for example, there are an intermittent mode in which cleaning is performed every predetermined number of sheets, and a continuous mode in which image formation is continuously performed without performing cleaning when the number of sheets is equal to or less than a preset limit number of sheets. At the time of this cleaning, the photosensitive drum rotates for a predetermined time, so that the use condition of the photosensitive drum differs depending on the print mode.

Also, the photoconductor drum may rotate for a predetermined time when the cover of the apparatus is opened and closed, and when various interrupt processes are performed, and the usage of the photoconductor drum may vary depending on the degree of rotation. .

Therefore, when the life of the photosensitive drum is determined based only on the number of recording sheets used for image formation as in the prior art, there is a possibility that a result suitable for the usage state of the photosensitive drum may not be obtained. There was a problem.

[0007] The present invention has been made in view of such circumstances, and not only the number of recording sheets used for image formation, but also
An object of the present invention is to provide an image forming apparatus capable of improving the accuracy of predicting the life of a photosensitive drum by considering the rotation time of the photosensitive drum.

Another object of the present invention is to provide a method in which the alarm is issued based on the predicted life of the photosensitive drum, and when the rotation time of the photosensitive drum has passed a predetermined time, and when a predetermined number of recording sheets have been used. In some cases, or in any case, by stopping image formation, it is possible to provide an image forming apparatus capable of giving a user an appropriate period as a period for preparing a new photosensitive drum.

Further, another object of the present invention is to provide B4, A
3, the life of the photosensitive drum is calculated by counting the number of recording sheets used for image formation using a conversion value for converting the number of recording sheets of A5 size or the like based on a predetermined size such as A4 size. It is an object of the present invention to provide an image forming apparatus capable of further increasing the prediction of the image formation.

[0010]

According to a first aspect of the present invention, there is provided an image forming apparatus comprising: a measuring unit for measuring a rotation time of a photosensitive drum; a counting unit for counting the number of recording sheets used for image formation; A life estimating unit for estimating the life of the photosensitive drum based on the rotation time when the time exceeds a predetermined time and based on the number when the number exceeds the predetermined number. I do.

According to the first aspect, the rotation time of the photosensitive drum is measured, the number of recording sheets used for image formation is counted, and when the measured rotation time exceeds a predetermined time, the measured rotation time is measured. When the counted number exceeds a predetermined number, the life of the photosensitive drum is estimated based on the counted number. Compared to the case where the life is predicted based only on the number of sheets of paper, the life can be predicted more in accordance with the usage state of the photosensitive drum.

The image forming apparatus according to a second aspect of the present invention is the image forming apparatus according to the first aspect of the present invention, wherein the alarming section notifies an alarm based on the life of the photosensitive drum predicted by the life estimating section. And stopping means for stopping the image formation when the rotation time of the photosensitive drum has passed a predetermined time after the notification by the above and / or when the number of recording sheets used for image formation has exceeded the predetermined number. It is characterized by.

According to the second aspect, an alarm is notified based on the predicted life of the photosensitive drum, and after the notification, when the photosensitive drum rotates for a predetermined time and when the number of recording sheets used for image formation is a predetermined number. The image formation is stopped when the number of images exceeds the number of images, or in any case.

Thus, a period for preparing a new photosensitive drum can be given to the user. Further, the period is determined based on the rotation time of the photosensitive drum and / or the number of recording sheets used for image formation, so that the period can be set to an appropriate period so that image defects do not occur.

The image forming apparatus according to a third aspect of the present invention is the image forming apparatus according to the first or second aspect, wherein the counting means counts the number of recording sheets used for image formation by size. A storage unit for storing a conversion value for converting the number of recording sheets of the size used for image formation into a number based on a predetermined size for each size of recording paper; Is converted based on the conversion value.

According to the third aspect of the present invention, a conversion value for converting the number of recording sheets of B4, A3, and A5 sizes based on a predetermined size such as A4 size is stored for each recording sheet size. Using the converted value, the number of recording sheets used for image formation is converted into the number based on a predetermined size.

Thus, the life can be predicted in consideration of the usage amount of the photosensitive drum according to the size of the recording paper, so that the prediction of the life of the photosensitive drum can be further enhanced.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings showing the embodiments. FIG. 1 is a block diagram showing a configuration example of a facsimile apparatus which is an electrophotographic image forming apparatus according to the present invention. In FIG. 1, reference numeral 1 denotes an MPU as a control unit of the facsimile machine. A ROM 2 preliminarily stores a program for controlling the operation of the facsimile machine, data necessary for control by the MPU 1, and a control operation. A RAM 3 for storing data or the like that needs to be temporarily stored is connected.

In the present embodiment, when the number of recording sheets used for image formation is calculated based on, for example, A4 size, the number of recording papers used for image formation, such as B4, A3, A5, etc.
A conversion value table is provided in the RAM 3 for storing a conversion value for converting the number of recording papers other than the four sizes into a number based on the A4 size for each recording paper size (see FIG. 2). .

The MPU 1 has an NCU (Network Control Uni
t) 4, modem 5 is connected. The NCU 4 is controlled by the MPU 1 to control the connection between the line L and the facsimile device, and to transmit dial pulses corresponding to the telephone number (facsimile number) of the communication partner and to detect the incoming call. Have. The line L is connected to a general public line (not shown). The modem 5 modulates and demodulates transmission / reception data, that is, modulates transmission data, which is originally a digital signal, into an analog voice signal and sends it out to the line L via the NCU 4, and conversely, receives it from the line L via the NCU 4. Demodulates analog audio signals into digital signals.

The MPU 1 is further connected to a reading unit 6, an image memory 7, a codec (CODEC) 8, a recording unit 9, an operation unit 10, a display unit 11, and the like.

The reading section 6 reads a document image by a scanner using, for example, a CCD image sensor.
The image memory 7 stores the image data read by the reading unit 6 and stores the image data received from the line L via the NCU 4 and the modem 5. The codec 8 encodes image data to be transmitted and decodes received image data. As will be described in detail later, the recording unit 9 functions as a unit for performing hard copy output by recording the received image data or the image data read by the reading unit 6 on recording paper (paper).

The operation unit 10 includes ten keys for inputting numbers such as telephone numbers, speed dial keys, one-touch keys, and operation keys for instructing various operations. The display unit 11 outputs and displays various information such as a telephone number input by operation of the operation unit 10 and a message for prompting replacement of the photosensitive drum of the recording unit 9.
It is composed of a T display or an LCD (liquid crystal display).

Next, the recording section 9 will be described. Recorder 9
Is connected to the MPU 1 by an input / output interface (I / O) 90a and a codec 90b. The I / O 90a mainly controls signals relating to the mechanical operation of the recording unit 9, and the codec 90b is used for image formation. Of the image data.

The recording unit 9 itself has, as main components, a photosensitive drum 91, an LED array 92, a developing unit 93, and a transfer roller 94, similarly to a conventional electrophotographic image forming apparatus.
And a charging brush 95 and the like.

The photoconductor drum 91 is a photoconductor charged by exposure, and is driven to rotate in the direction of the arrow. A rotation time counter TC is connected to the photosensitive drum 91, and the rotation time counter TC causes the photosensitive drum 9 to rotate.
One rotation time is counted, and the count value is I / O 9
0a to MPU1. The MPU 1 estimates the life of the photosensitive drum 91 based on the count value as described later.

The rotation time counter TC may be connected to a motor (not shown) for rotating the photosensitive drum 91. In this case, the rotation time counter TC counts the driving time of the motor to thereby rotate the photosensitive drum 91. Will be measured.

The LED array 92 exposes the photosensitive drum 91 according to the image data by the I / O 90a, and forms an electrostatic latent image on the photosensitive drum 91. The developing device 93 has a paddle 93 for stirring the toner stored therein.
1 and a roller for transporting the toner to the photosensitive drum 91 so as to be selectively attracted to the photosensitive drum 91. The toner adheres to the electrostatic latent image formed on the photosensitive drum 91.

The transfer roller 94 is opposed to the photosensitive drum 91 in a state where it is pressed, and follows the photosensitive drum 91 to transfer an image (toner image) formed by attaching toner to the electrostatic latent image. Transfer to paper. The charging brush 95 is provided on the photosensitive drum 91 and removes toner remaining on the peripheral surface of the photosensitive drum 91 after the transfer.

In the present embodiment, the photosensitive drum 91
LED array 9 as a means for forming an electrostatic latent image thereon
2, a system for projecting a laser beam onto the photosensitive drum 91 to form an electrostatic latent image, a system for projecting a light beam using an LED shutter, or the like may be used.

Reference numeral 96 denotes a paper cassette in which the paper is stored, 97 denotes a pickup roller for taking out one of the uppermost layers of the paper stored in the paper cassette 96, and 98 denotes a power supply from the I / O 90a. A solenoid 99 connects and disconnects the rotational driving force of the motor M to the pickup roller 97 in accordance with the condition.
Reference numeral 100 denotes a fixing roller and a paper sensor for detecting that the sheet has reached a predetermined position immediately before.

A dashed line indicated by reference numeral 101 indicates a paper transport path from the paper cassette 96 to the fixing roller 100.

A control signal S1 for disconnecting the motor M from the pickup roller 97 is supplied to the solenoid 98 by the MPU.
1 through I / O 90a. Paper sensor 99
To the MPU 1 via the I / O 90a a detection signal S2 indicating its on / off, that is, whether or not the arrival of the sheet is detected.

In the facsimile apparatus having the above-described configuration, when the control signal S1 is given from the MPU 1 via the I / O 90a, the rotational driving force of the motor M is connected to the pickup roller 97 and One sheet of paper is picked up by a pickup roller 97 and transported to a paper sensor 99. Paper sensor 9
When the MPU 9 detects the arrival of the sheet and outputs the detection signal S2, the MPU 1 causes the codec 90b to output image data to the LED array 92 at a predetermined timing. Thus, the photosensitive drum 91 rotates while an electrostatic latent image is formed on the surface thereof, and the toner is selectively adsorbed by the developing device 93 to form a toner visible image.

On the other hand, the sheet is further conveyed from the position of the sheet sensor 99 to a position where the photosensitive drum 91 and the transfer roller 94 are opposed to each other and sent between them, and a toner image is transferred to the surface thereof. Further, the toner image is fixed by being heated and pressed by the fixing roller 100.

Next, the operation flow of the facsimile apparatus which is the image forming apparatus of the present invention having the above-described configuration will be described with reference to FIG.
A description will be given based on the flowchart of FIG. When receiving the image data via the line L, the facsimile apparatus drives a motor for rotating the photosensitive drum 91 (S10).
1), the photosensitive drum 91 is cleaned (S10).
2). Here, the cleaning is a process of removing the toner remaining on the peripheral surface of the photosensitive drum 91 by the charging brush 95. At this time, the photosensitive drum 91 rotates for a predetermined time.

Next, the facsimile apparatus records one page of the received image data on a recording sheet (S103). Then, a process of counting the number of recording sheets used for image formation is performed (S104).

Here, the procedure for counting the recording paper in step S104 is described in the conceptual diagram of the conversion value table shown in FIG. 2A and the conceptual diagram showing an example of the paper size shown in FIG. 2B, and FIG. Description will be made based on the flowchart shown. As shown in FIG. 2B, the conversion value table in FIG. 2A is A4 size recording paper scanned vertically and A3 or B4 scanned vertically or scanned horizontally. A
5 shows a conversion value based on the A4 size determined based on the ratio of the length of each size of recording paper in the sub-scanning direction.

In the following description, the size-based counter is a counter for counting the number of times of printing for each size of A4, A3, B4, and A5. The total number counter is a counter for counting a total value (total number) of recording sheets used for image formation converted based on A4 size.

The facsimile apparatus adds 1 to the size counter according to the size of the recording paper used for recording in step S103 (S201). That is, for example, if A4 size recording paper is used in step S103, A
One is added to the size-specific counter for B4, and 1 is added to the size-specific counter for B4 when B4 size recording paper is used.

Next, referring to the conversion value table described above,
The conversion value corresponding to the count value of the size-based counter is added to the total number of sheets counter (S202). Then, it is determined whether or not the count value of the size-specific counter has reached the upper limit of the number of prints indicated in the conversion value table (S203). That is, in the case of the size-specific counter for B4, for example, as shown in FIG.

If it is determined in step S203 that the count value of the size-specific counter has not reached the upper limit of the number of prints (NO in S203), the process ends. On the other hand, when it is determined that the upper limit has been reached (YE in S203).
S), the size-based counter is cleared to 0 (S20)
4) The process ends later.

Returning to the description of FIG. 3, after the process of step S104, the facsimile apparatus performs a process of estimating the life of the photosensitive drum 91 described later (S105). Then, it is determined whether or not all the pages of the received image data have been recorded (S106). If it is determined that there are still remaining pages (NO in S106), the process returns to step S103. On the other hand, when it is determined that all the pages have been recorded (YES in S106), the cleaning process of the photosensitive drum 91 is performed (S107), and the process ends.

Next, the procedure for estimating the life of the photosensitive drum 91 in step S105 will be described with reference to the flowchart shown in FIG. In the following description,
It is the total of the total rotation time and the rotation time of the photosensitive drum 91, and is a value counted by the rotation time counter TC. The preparation flag is a flag for determining whether or not a preparation message described later is displayed. When the preparation message is displayed as described later, the value is set to 1.
And 0 when not displayed.

First, it is determined whether or not the preparation message has already been displayed by confirming whether or not the value of the preparation flag is 1 (S301). Here, if the value of the preparation flag is 0, that is, if the preparation message is not displayed (NO in S301), the total number of sheets exceeds the preset upper limit of the number of sheets by referring to the count value of the total number of sheets counter. Is determined (S30).
2).

If it is determined in step S302 that the total number of sheets does not exceed the upper limit of the number of sheets (N in S302
O), referring to the count value of the rotation time counter TC, it is determined whether or not the total rotation time exceeds a preset rotation time upper limit value (S303). Here, if it is determined that the total rotation time does not exceed the rotation time upper limit value (NO in S303), it is determined that the life of the photosensitive drum 91 is not yet completed, and the process is terminated.

On the other hand, when it is determined in step S302 that the total number exceeds the upper limit of the number (YES in S302), or when it is determined in step S303 that the total rotation time exceeds the upper limit of the rotation time. (S30
3; YES), a preparation message instructing preparation of a new photosensitive drum 91 because the life of the photosensitive drum 91 is approaching (for example, “Please prepare the drum”).
, Etc.) are displayed on the display unit 11 (S304). Then, 1 is set to the preparation flag (S305), and the process ends.

On the other hand, if the value of the preparation flag is 1 in step S301, that is, if the preparation message has already been displayed (YES in S301), the total number of sheets is limited by referring to the count value of the total number of sheets counter. It is determined whether the number exceeds the number (S306). Here, the limit number of sheets is a value determined based on the durability of the photosensitive drum 91, and is a limit value of the number of recording sheets that can be recorded. Note that the limit number may be set in advance on the device side or may be set by the user. Also, if the user should set the limit number of sheets, but the user has operated without setting it,
A predetermined value may be automatically set on the device side.

When it is determined in step S306 that the total number does not exceed the limit number (N in S306
O), it is determined that the limit of use of the photosensitive drum 91 has not been reached, and the process ends. On the other hand, when it is determined that the total number exceeds the limit number (YES in S306), it is determined whether or not the total rotation time exceeds the limit time by referring to the count value of the rotation time counter TC (S3).
07). Here, the limit time is a value determined based on the durability of the photosensitive drum 91 in the same manner as the above-described limit number of sheets, and is a limit value of the rotation time of the photosensitive drum 91. Note that this limit time can be set by the various methods described above, similarly to the case of the limit number of sheets.

When it is determined in step S307 that the total rotation time does not exceed the limit time (N in S307
O), it is determined that the limit of use of the photosensitive drum 91 has not been reached, and the process ends. On the other hand, when it is determined that the total rotation time exceeds the limit time (YE in S307).
S) An exchange message (for example, “Please replace the drum”) indicating that the use of the photosensitive drum 91 has reached the limit and to be replaced with a new photosensitive drum 91 is displayed on the display unit 11. (S308).

Next, it is determined whether or not replacement with a new photosensitive drum 91 has been performed (S309). If replacement has not been performed (NO in S309), a replacement message is sent until replacement is performed. Continue the display. Therefore, the image formation is stopped until the photosensitive drum 91 is replaced with a new one.

If the photosensitive drum 91 has been replaced with a new one (YES in S309), the total number of sheets, the total rotation time, the limit number of sheets, the limit time, and the value of the preparation flag are reset (S310). finish.

In the above-described processing, step S
Although each of the limit number and the limit time is checked in each of the steps 306 and S307, only one of them may be checked. That is, it is not necessary to confirm whether the limit number or the limit time has been exceeded. In this case, it is possible to perform the processing more easily than in the case of confirming the excess of both.

In order to facilitate handling, the photosensitive drum 91 is often formed as a cartridge integrally with the charging brush 95 and the like. In this case, the entire cartridge is replaced. Therefore, the charging brush 95 and the like are also
1 will be replaced at an appropriate time according to the life of the battery.

[0055]

As described in detail above, according to the image forming apparatus of the first aspect, the rotation time of the photosensitive drum is measured, the number of recording sheets used for image formation is counted, and the measured rotation is measured. The life of the photosensitive drum is predicted based on the measured rotation time when the time has passed a predetermined time, and based on the counted number when the counted number exceeds the predetermined number. This makes it possible to predict the life in accordance with the usage state of the photosensitive drum, as compared with the case where the life is predicted based only on the number of recording sheets used for image formation as in the related art.

According to the image forming apparatus of the present invention, an alarm is notified based on the predicted life of the photosensitive drum, and after the notification, the photosensitive drum is rotated for a predetermined time and used for image formation. By stopping image formation when the number of recording sheets exceeds a predetermined number, it is possible to give the user an appropriate period for preparing a new photosensitive drum.

Further, according to the image forming apparatus of the present invention, a conversion value for converting the number of recording papers of B4, A3, A5 size or the like based on a predetermined size such as A4 size is used as the size of the recording paper. By separately storing the converted value and converting the number of recording sheets used for image formation into a number based on a predetermined size using the conversion value, the amount of use of the photosensitive drum according to the size of the recording sheet is considered. The present invention has excellent effects, for example, since the life expectancy can be predicted, and the life expectancy of the photosensitive drum can be further enhanced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a facsimile apparatus that is an electrophotographic image forming apparatus according to the present invention.

FIG. 2 is a conceptual diagram illustrating a conversion value table and a conceptual diagram illustrating an example of a sheet size.

FIG. 3 is a flowchart showing a flow of an operation of the facsimile apparatus which is the image forming apparatus of the present invention.

FIG. 4 is a flowchart illustrating a procedure for counting the number of recording sheets in step S104.

FIG. 5 is a flowchart illustrating a procedure for estimating the life of the photosensitive drum in step S105.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main control part 9 Recording part 91 Photoreceptor drum 95 Charging brush TC Rotation time counter

Claims (3)

[Claims] 1. A measuring means for measuring a rotation time of a photosensitive drum, a counting means for counting the number of recording sheets used for image formation, and based on the rotation time when the rotation time exceeds a predetermined time. An image forming apparatus comprising: a life prediction unit configured to predict a life of the photosensitive drum based on the number when the number exceeds a predetermined number. 2. A notifying means for notifying an alarm based on the life of the photosensitive drum predicted by the life predicting means, and when the rotation time of the photosensitive drum has passed a predetermined time after the notification by the notifying means. 2. The image forming apparatus according to claim 1, further comprising: a stop unit configured to stop image formation when the number of recording sheets used for image formation exceeds a predetermined number. 3. The counting means counts the number of recording sheets used for image formation by size, and converts the number of recording sheets used for image formation into a number based on a predetermined size. A storage unit for storing a converted value for each size of recording paper, wherein the number of recording sheets used for image formation is converted based on the converted value. 3. The image forming apparatus according to 2.