JPH0580607A - Electrophotographic device - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] Without using an expensive mechanical counter,
To record the total number of times of image formation from the start of use of the apparatus by using an inexpensive nonvolatile memory element so that the number of times can be notified. A first counter 25 that updates a count value each time an image is formed, a second counter 24a that counts the number of times the first counter 25 has been replaced, and the first counter 25 have a predetermined value or more. In the case of, notification means 29, 30 for giving an alarm
And a display means for calculating and displaying the sum of the image formation number data of the first counter 25 and the image formation number data of the second counter 24a based on the count value of the second counter 24a and the predetermined value. Consists of.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus used in a laser beam printer, a copying machine or the like, and an improvement of an informing means for informing the number of times of image formation executed by the apparatus to facilitate maintenance. Regarding

[0002]

2. Description of the Related Art An electrophotographic apparatus develops an electrostatic latent image formed by exposing a charged photosensitive member with a developer such as toner and transfers the toner image onto a recording medium to form an image on the recording medium. To form. Since the photosensitive member is deteriorated by repeated exposure of the photosensitive material constituting the photosensitive member or contact with ozone generated by discharge of a discharger used for charging, the photosensitive member is a consumable part. If it is handled and deteriorates and the quality of the image deteriorates, replacement is required.

Therefore, in a conventional printer using the electrophotographic method, paying attention to the number of recording media printed as information regarding the life of the photoconductor, the number of printed sheets is counted by a sheet counter using a non-volatile storage element, and When the count value reaches a predetermined value, it is detected and displayed to notify the user of the replacement of the photoconductor (see Japanese Patent Laid-Open No. 62-75468).

The number counter is designed to be replaced with a new one when the photoconductor is replaced. The number counter has an initial value every time the photoconductor is replaced. With that, it is not possible to count the total number of prints from the start of using the electrophotographic device,
Components other than the photoconductor of the electrophotographic apparatus, for example, a charging unit,
In order to manage the timing of maintenance work of the components such as the developing device, the transfer unit, and the static eliminator that have a relatively long usable period, a mechanical counter for counting the total number of printed sheets is provided separately from the above-mentioned number counter. It was provided.

[0005]

However, since the mechanical counter is generally provided in a place where it is difficult to see inside the main body of the apparatus, it is easy to overlook that the maintenance target component is at the end of its service life, and a failure due to the service life is likely to occur. It was easy to invite. Further, since the mechanical counter is expensive, there is a problem in terms of price.

In view of the above problems of the prior art, the present invention records the total number of image formations from the start of use of the apparatus using an inexpensive nonvolatile memory element without using an expensive mechanical counter. However, the purpose is to be able to inform the number of times.

[0007]

In the electrophotographic apparatus of the present invention, an electrostatic latent image is formed on a photoconductor, and the toner image developed with a developer is transferred to a recording medium for recording. In an electrophotographic apparatus for forming an image on a medium, a first counter which is detachably provided in the apparatus main body and which is composed of a non-volatile memory element and updates a count value of image formation each time image formation is performed; A second counter configured by a non-volatile storage element that updates a count value when it is detected that the counter is in an initial state, an informing unit that issues an alarm when the first counter has a predetermined value or more, and an informing command. Display means for calculating and displaying the sum of the image forming count data based on the count value of the second counter and the predetermined value and the image forming count data of the first counter. Ah .

[0008]

In the electrophotographic apparatus of the present invention having such a structure, the first counter and the second counter composed of the non-volatile memory elements are used to make the number of times of image formation on the photosensitive member in use predetermined. When it is notified that the value has been reached,
Since the total number of image formations from the start of use of the electrophotographic apparatus is displayed by inputting the notification command, the user can easily confirm the total number of image formations.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a configuration diagram showing an arrangement of each component of a laser beam printer using an electrophotographic apparatus, in which a photosensitive drum 2 (photoreceptor) is disposed substantially in the center of a housing 1. The photosensitive drum 2 is rotationally driven in one direction by a drive motor 3, that is, clockwise in the drawing, and the surface of the photosensitive drum 2 is uniformly charged according to an electrophotographic process according to an electrophotographic process. An electrostatic latent image is formed on the surface of the photosensitive drum 2 by irradiating the charging unit 4 and the photosensitive drum 2 uniformly charged by the charging unit 4 with a laser beam controlled by information to eliminate the charge according to the information. The exposed portion 5 to be formed, and the toner 6 as a developer on the electrostatic latent image on the surface of the photosensitive drum 2 formed by being exposed by the exposed portion 5.
Developing unit 7 for adhering and developing a toner image as a toner image, a transfer unit 9 for transferring the toner image of the photosensitive drum 2 onto a conveyed sheet 8 (recording medium), and a cleaning unit 10 for removing residual toner from the surface of the photosensitive drum 2. A charge eliminating section 11 for eliminating charges remaining on the surface of the photosensitive drum 2 is sequentially arranged in the rotation direction of the photosensitive drum.

The transfer portion 9 is located below the photosensitive drum 2,
A paper feed cassette 12 provided on one side of the housing 1 toward the transfer unit 9 sends a paper 8 one by one by the operation of a pickup roller 13 according to a paper feed command, and the transport rollers 14 and 14 are fed. In this way, the sheet is conveyed along the conveying path 15.

After the toner image on the photosensitive drum 2 is transferred by the transfer portion 9 to the conveyed paper 8, the paper 8 is fixed by the fixing device 16 and is ejected to the upper side of the housing 1 by the paper ejection rollers 17, 17. It is like this.

The casing 1 is composed of an upper casing 1a and a lower casing 1b, and the photosensitive drum 2 of each of the constituent members has a charging portion 4, a developing portion 7, a cleaning portion 10,
At least one of the static elimination units 11 is integrally incorporated via the support member of the photosensitive drum 2, and is attached to the lower housing 1b together with the photosensitive drum 2 so as to be easily attached and detached. Regarding the other components, the components arranged above the conveyance path 15 for the paper 8 are incorporated in the upper casing 1a, and the components arranged below are incorporated in the lower casing 1b.

The upper housing 1a is a lower housing 1b.
The photosensitive drum 2 can be detached from the lower casing 1b together with the components integrally formed with the upper casing 1a by opening the upper casing 1a. The structure is such that the conveyance path 15 for the paper 8 is opened by. A memory card (first counter) described later is detachably provided in a part of the lower housing 1b that is opened when the upper housing 1a is opened, and the upper housing 1a of the lower housing 1b is further attached. A cover open switch 18 for detecting the open / closed state of the upper housing 1a is provided at a position where the cover is opened / closed.

The charging section 4, the exposing section 5, the developing section 7, the transfer section 9, the cleaning section 10, the charge eliminating section 11 and the fixing section 16 are provided.
The number of prints that can be printed with one photosensitive drum 2 (about 100
When the number of printed sheets (about 80,000 sheets) is printed more than 00 sheets, it is a maintenance target constituent member that requires replacement or maintenance work.

FIG. 1 is a block diagram showing an electrical hardware configuration of the printer. A lead in which program data and the like are stored in advance via a bus line 21 in a central processing unit (CPU) 20 which constitutes a main body of a control unit. -Only memory (ROM) 22, random access memory (RAM) 23 in which a print buffer for expanding print data as image data is formed, and an electrically erasable programmable memory for storing various printer-specific setting values ROM (EEPR
OM, non-volatile memory element) 24, a memory card 25 as a first counter which is detachably mounted so that it can be replaced when the photosensitive drum 2 is replaced, and which is composed of a non-volatile memory element for storing the number of times of image formation. A card interface 26 for reading and writing data, a transmission interface 27 for transmitting and receiving data to and from a host device (not shown), and an I / O port 28 are connected.

The I / O port 28 has a liquid crystal display 29 for displaying various messages and the like, a buzzer 30 for notifying the replacement of the photosensitive drum 2, a high voltage power supply circuit 31 for supplying a high voltage to the charging section 4 and the transfer section 9. , A motor drive circuit 32 for controlling the drive of the drive motor 3, an instructing command key 33a for inputting an instructing command for instructing the display of the total number of printed sheets, and an operation unit 33 and a cover open switch configured by various kinds of keys 18 etc. are connected.

The memory card 25 is for storing a count value N1 of the number of printed sheets (the number of times of image formation) as information concerning the life of the photosensitive drum 2, and is a replacement part which is a set with the photosensitive drum 2. When the photosensitive drum 2 is replaced, the memory card 25 is also replaced.

The reason why the memory card 25 is replaced with the photosensitive drum 2 is to detect replacement of the memory card 25 and to consider that the photosensitive drum 2 has been replaced by the replacement, as will be described later. Also cheap E
EPROMs have a small number of guaranteed write operations (usually 10
(000 times or less), when the number of printable sheets of one photosensitive drum 2 is exceeded and the total number of printable sheets of the photosensitive drums 2 is counted, the number of writing times exceeds the guaranteed number. Since the reliability of the count value cannot be guaranteed, it cannot be used as a count counter that normally exceeds 10,000 times. When counting 10,000 times, replace it with one that guarantees a new writing of 10,000 times. As described above, the mechanical counter has conventionally been used to know the total number of printed sheets from the start of use of the printer, as described above.
Since the number of guaranteed writing times is small, even if you try to count the number of printed sheets using the EEPROM, you cannot
It is conceivable that the total number of prints printed on M reaches the guaranteed number of writings at the time of counting 10,000 sheets, and the counted value of the number of printed sheets beyond that becomes unreliable.

The EEPROM 24 stores various set values of the main body of the apparatus, and a replacement count storage section 24a as a second counter for storing the replacement count n of the memory card 25 as the replacement count of the photosensitive drum 2. And a photoconductor limit number storage unit 24 for storing the photoconductor limit value A.
b, a maintenance time printed number storage unit 24c that stores a number value B indicating that the time when the total number of printed sheets reaches this number is the maintenance work time, and this maintenance time printed number storage unit 24
The maintenance required print number storage unit 2 for storing the number value B1 for updating the number value B of c to the number value indicating the next maintenance time.
4d is formed.

Next, the control of the printer will be described with reference to the flowchart (FIG. 3) showing the control when the power is turned on.

That is, when the power is turned on, a predetermined initial process is performed (ST100), and then the stored data of the memory card 25, that is, the number of printed sheets N1 is read through the card interface 26 (ST10).
1). Then, it is judged whether the number of printed sheets N1 is "0" (ST
102), if N1 = 0 is not satisfied (greater than “0”), it means that it is not immediately after the replacement of the photosensitive drum 2. Therefore, the usage status of the photosensitive drum 2 is set to the preset limit number of photosensitive members to be used. The value is compared with a corresponding predetermined value A (for example, 10000 sheets) (ST103). At this time, if the number of printed sheets N1 is equal to or larger than the usable number of sheets of the photosensitive drum 2, the liquid crystal display 29 indicates that it is time to replace the photosensitive drum 2, and the buzzer 30 notifies the user of the fact. (ST104). This ST101, ST10
2, ST103, ST104, the liquid crystal display 30 and the buzzer 31 constitute an informing means.

On the other hand, the number of printed sheets N1 is the photosensitive drum 2
When the number of sheets is less than the usable limit number A, it is not the time to replace the photosensitive drum 2, and the process proceeds to the printing process (ST112).

When the number of printed sheets N1 is "0" in ST102, it is judged that the photosensitive drum 2 and the memory card 25 have been exchanged with new ones, and the stored data of the exchange number storage section 24a, that is, the exposure performed after the previous maintenance work. The number of exchanges n of the drum 2 is read (ST105), and the total number of printed sheets N2 is calculated based on the number of exchanges n and the predetermined value A (ST105).
106). This relationship is expressed by the following equation (1).

[0024]

## EQU1 ## N2 = n × A (1)

Then, "1" is added to the stored data n in the exchange count storage section 24a (ST107) to update the stored data, and "1" is written in the memory card 25 to print N sheets.
When 1 is set to "1", the memory card 25 is processed to the effect that the number of exchanges has been counted (ST108).

Next, the calculation result N2 in ST106 is compared with the predetermined value B stored in the maintenance time print number storage section 24c (ST109). If N2 ≧ B, it means that it is the maintenance time. The buzzer 30 is driven by displaying on the liquid crystal display 29 (ST110).

Further, at this time, the maintenance time print number storage section 24
The predetermined value B1 stored in the maintenance required print number storage unit 24d is added to the predetermined value B of c to obtain the maintenance time print number storage unit 24.
The predetermined value B of c is updated to the maintenance time print number value indicating the next maintenance time (ST111). This "B1" is the number of prints that can be printed after the maintenance work and before the next maintenance work.
That is, when the number of prints B1 is printed, the number of prints corresponds to the number of prints required for the next maintenance work.
By adding 1, the predetermined value B of the maintenance time printed sheet number storage unit 24c is updated to the printed sheet number when the next maintenance time is when the total printed sheet number N2 reaches B next time.

As a result, the user knows that the maintenance of the constituent members is necessary in addition to the replacement of the photosensitive drum 2, and can request the maintenance work. In addition, the above (ST10
When the total number of printed sheets N2 does not reach the predetermined value B in 9), the process proceeds to the printing process (ST112).

Next, in the print processing shown in FIG. 4, the transmission interface 27 is checked to determine whether print data has been received (ST200). When the print data is received, the stored data of the memory card 25 mounted via the card interface 26, that is, the number of printed sheets N1 is read (ST20).
1). Then, the printing process is executed based on the print data (ST202), and the value obtained by adding "1" to the number of printed sheets N1 is written in the memory card 25 as the current number of printed sheets N1 to update the number of printed sheets N1 (ST203). ..

If the print data is not received in ST200, it is judged whether or not the instruction for displaying the total number of printed sheets is given, that is, whether the notification command is input (ST204). If the notification command is input, Card interface 26
The stored data of the memory card 25 mounted via the printer, that is, the number of printed sheets N1 is read (ST205), and the number of times n the photosensitive drum 2 has been exchanged is read from the exchange number storage section 24a (ST206) to calculate the total number of printed sheets N2. (ST2
07), and the count value N2 is displayed on the liquid crystal display 29 (ST208). The relationship of the total number of printed sheets N2 is expressed by the following equation (2).
Represented by

[0031]

(2) N2 = n × A + N1 (2)

The above ST205, ST206, ST20
7, ST208 and the liquid crystal display 29 constitute a display means.

If neither print data is received nor a notification command is input, other processing is executed (ST20).
9). Then, this printing process is repeatedly executed.

Further, in the printing process, the state of the cover open switch 18 for detecting the open / closed state of the housing 1a is detected at every appropriate step, and when the cover open is detected, the state shown in FIG. The processing of the flowchart shown is executed.

First, for example, a cover open process is executed to turn off the heater of the fixing device 16 or to notify the host device that the cover is open (ST3).
00), waiting for the upper casing 1a to be closed, that is, detecting the state of the cover open switch 18
Wait for the detection of closing (ST301). And
When the cover close is detected, the cover close processing, for example, the notification that the cover open state has been resolved is executed to the host device (ST302), and the process proceeds to the execution of the processing after ST101 of the power-on processing. ..

When the cover open is detected, the process after ST101 is performed when the cover is closed, so that even if the memory card 25 is replaced with the power on, this replacement is always detected. It is possible.

As described above, according to the present embodiment, when the photosensitive drum 2 prints a predetermined number of prints and the photosensitive drum 2 reaches the time to be replaced, it can only be notified that it is the replacement time. In addition, the maintenance time can be notified each time for other maintenance target parts, and a part of the non-volatile storage element for storing various setting information can be replaced with the replacement frequency storage section 24a of the memory card 25 without using a mechanical counter.
By counting the number of times the photosensitive drum 2 has been replaced, the total number of printed sheets from the start of use of the printer can be displayed as necessary, so that the total number of printed sheets from the start of use can be easily known. ..

The present invention is not limited to the above embodiment. For example, the notification command may be input from the host device, and the replacement of the photosensitive drum 2 may be performed by the memory card 2.
It is also possible to detect the mounting state of No. 5 and wait for the mounting to be detected in the case of no mounting, and determine that the replacement is performed according to the detection of mounting. Further, in the above-described embodiment, the alarm sound from the buzzer 30 may be distinguished when the photosensitive drum 2 in use has reached a predetermined number of prints and when it is time to maintain other maintenance target parts. By doing so, the liquid crystal display 2
The message display by 9 can be omitted. Further, the alarm may be given only by displaying the message on the liquid crystal display 29, and the alarm sound by the buzzer 30 may be omitted.

A predetermined value B for determining the maintenance time of the maintenance target component is provided for each maintenance target component (replacement number storage unit 2
It is also possible to provide a plurality of 4a) so that different maintenance times can be notified for a plurality of maintenance parts.

[0040]

As described in detail above, according to the present invention, it is possible to easily notify the maintenance time and the like since the photosensitive member replacement time and the total number of image formations of the electrophotographic apparatus can be notified with a simple and inexpensive structure. An electrophotographic device can be provided at low cost.

[Brief description of drawings]

FIG. 1 is an electrical hardware configuration diagram of a laser beam printer showing an embodiment of an electrophotographic apparatus of the present invention.

FIG. 2 is a configuration diagram showing an arrangement of respective components of the laser beam printer shown in FIG.

FIG. 3 is a flowchart showing processing when the power is turned on in the laser beam printer shown in FIG.

4 is a flowchart showing a printing process in the laser beam printer shown in FIG.

5 is a flowchart showing a process at the time of cover open detection in the laser beam printer shown in FIG.

[Explanation of symbols]

 2 Photosensitive drum (photoreceptor) 24a Replacement frequency storage unit (second counter) 25 Memory card (first counter) 29 Liquid crystal display 30 Buzzer

Claims (1)

[Claims] 1. An electrophotographic apparatus for forming an image on a recording medium by forming an electrostatic latent image on a photoconductor and transferring the toner image developed by the developer to the recording medium. A first counter which is detachably provided in the apparatus body and which is composed of a non-volatile memory element and updates the count value of image formation each time image formation is performed; and when it is detected that the first counter is in an initial state. A second counter composed of a non-volatile memory element for updating the count value, an informing means for issuing an alarm when the first counter is equal to or greater than a predetermined value, and a counter for the second counter based on the input of an informing command An electrophotographic apparatus, comprising: a display unit that calculates and displays a sum of image formation count data based on a numerical value and the predetermined value and image formation count data of the first counter.