JPH03213378A - Electrophotographic apparatus - Google Patents

Abstract

PURPOSE:To prevent the lowering of printing quality due to the life of a photosensitive body and to enhance the use efficiency of the photosensitive body by comparing the number of printing sheets with the limit number of printing sheets each time when printing is started and executing printing operation when the number of printing sheets is below the limit number thereof. CONSTITUTION:A CPU 31 judges a printing start state to control a card interface 43 and reads the number-of-printing sheet data and limit number-of-printing sheet data recorded on the memory card 42 mounted on the interface 43 to compare both data. When the number of printing sheets is below the limit number thereof, the number-of-printing sheet data recorded on the memory card 42 is updated and a printing routine is executed. When the number of printing sheets coincides with the limit number thereof, a message urging the replacement of a photosensitive drum is displayed on the display device provided to an operation part 41 to prohibit the transfer to the printing routine.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a dry electrophotographic apparatus such as a laser printer.

[Prior Art] In recent years, for example, in laser printers, components such as a photoreceptor, a charging section, a developing section, and a transfer section, which are built into the main body of the device, are combined into one drum unit, and this unit is detachable from the main body of the device. There is something like that. This has the advantage that when the photoreceptor deteriorates due to long-term use and reaches the end of its lifespan and needs to be replaced, the problem can be dealt with simply by replacing the unit, which simplifies maintenance work.

Conventionally, there is a known technology in which the number of pages printed by the printer is counted and stored as information regarding the lifespan of the photoreceptor, and the content of this count is displayed (Japanese Patent Application Laid-Open No. 7546/1983).
(See Publication No. 8). By using this technique, the operator can recognize the degree of deterioration of the photoreceptor from the current number of prints.

Therefore, when the number of printed sheets reaches a preset limit number of printed sheets, the drum unit may be replaced.

By doing so, deterioration in print quality due to deterioration of the photoreceptor can be prevented in advance.

[Problems to be Solved by the Invention] However, even in conventional laser printers in which the degree of deterioration of the photoreceptor is indicated by counting and storing the number of printed sheets and displaying the number, there are the following disadvantages. That is, in general, the sensitivity characteristics of photoreceptors and the degree of deterioration thereof vary depending on the photoreceptor. For this reason, in reality, the maximum number of printable sheets, which is the lifespan of a photoreceptor, also differs depending on the photoreceptor. However, conventionally, when a uniquely determined fixed print limit number of sheets is reached, it is determined that any photoreceptor has reached the end of its lifespan, and the drum unit is prompted to be replaced. For this reason, even if a photoreceptor has good sensitivity, it may have to be replaced because it has reached its printing limit, and the photoreceptor may not be used efficiently.

Therefore, the present invention provides an electrophotographic method in which the printing limit number of a photoreceptor can be arbitrarily set according to the sensitivity characteristics of the photoreceptor, and the efficiency of use of the photoreceptor can be improved while preventing deterioration of print quality due to the life of the photoreceptor. The aim is to provide equipment.

[Means for Solving the Problems] The present invention arranges a charging section, an exposure control section, a developing section, and a transfer section around a rotationally driven photoconductor according to an electrophotographic process, and a drum unit including at least the photoconductor is installed in an apparatus. In an electrophotographic apparatus that is detachably attached to the main body, a storage means is provided for storing print number data corresponding to the drum unit and print limit number data corresponding to the life of the photoreceptor included in the drum unit, and a , a comparison means for comparing the print number data stored by the storage means and the print limit number data; and when it is determined by the comparison means that the print number data does not reach the print limit number data, a printing operation is performed. and a printing execution control means that updates the print number data stored in the storage means by the number of print sheets, and a print prohibition control that prohibits the printing operation when it is determined that the print number data has reached the print limit number data. means and means.

[Function] In an electrophotographic apparatus having such a configuration, the number of print sheets and the print limit number are stored in a storage means provided corresponding to the drum unit, and the number of print sheets and the print limit are stored each time printing is started. The number of sheets is compared. Then, if the number of printed sheets is less than the print limit number of sheets, a printing operation is executed.

At this time, the number of printed sheets data stored in the storage means is updated by the number of printed sheets. On the other hand, when the number of printed sheets matches the print limit number of sheets, the printing operation is prohibited. Therefore, since the storage means stores the print limit number corresponding to the life of the photoreceptor included in the corresponding drum unit, the print limit number can be varied depending on the photoreceptor.

[Example] Hereinafter, an example in which the present invention is applied to a laser printer will be described with reference to the drawings.

FIG. 1 shows the overall structure of this embodiment of the apparatus, in which a drum unit 2 is provided in the center of a printer body 1 and is detachably attached to the printer body 1. As shown in FIG. The drum unit 2 includes a photosensitive drum 3 whose surface is formed of a photosensitive member. The photosensitive drum 3 is driven to rotate in one direction, and around the photosensitive drum 3 there is a charger 4 constituting a charging section, and the photosensitive drum 3 charged by the charger 4 according to the electrophotographic process. A laser scanner unit 5 serves as an exposure control section that irradiates a laser beam to record image information by exposure, a developer 6 that attaches toner as a developer to the exposed photosensitive drum 3, and a transfer charger that constitutes a transfer section. 7. A cleaning device 8 for removing toner from the photosensitive drum 3, and a charge removal lamp 9 for removing charge from the photosensitive drum 3 are provided in this order. Near the front entrance of the transfer charger 7 is a pickup roller 11 for feeding and conveying the paper stored in the paper feed section 10 toward the transfer charger 7 at a predetermined timing.
Or is provided. Further, behind the transfer charger 7, there is a thermal fixing device 12 for thermally fixing the transferred paper.
and a paper discharge roller 13 are provided in this order.

Furthermore, inside the printer main body 1, a transport motor 14,
A fan 15, an interlock switch 16 for detecting opening of the casing of the printer body 1, and a DC power supply 17 are provided, respectively.

As shown in FIG. 2, the laser scanner unit 5 includes a laser diode structure 21 that emits a laser beam, a laser diode control circuit 22 that drives this laser diode structure 21, a PIN diode that detects the starting position of the laser beam, etc. A start sensor 23, a polygon motor 24 that rotates a polygon mirror, a polygon motor drive circuit 25 that drives and controls this motor 24, and a PLL control circuit 26 that controls the number of rotations of the motor 24 driven by this drive circuit 25 are provided.

FIG. 3 is a block diagram showing the circuit configuration of this embodiment device, and 31 is a CPU (central processing unit) that constitutes the main body of the control section.
, 32 is a ROM (read-only memory) in which program data and various tables for controlling each part of the CPU 31 are provided, and 33 is a ROM (read-only memory) for storing image information and various processing data sent from an external host computer. RAM (Random Access Memory) 34 is an I10 port. These are connected by a pass line 35.

The I10 port 34 includes a motor drive circuit 36 that drives and controls the transport motor 14, a high voltage power supply circuit 37 that supplies high voltage to the laser scanner unit 5, the charger 4 and the transfer charger 7, and the developer 6.
A toner sensor circuit 40 that controls a toner empty sensor 38 and a toner full sensor 39 provided therein, an operation section 41 that is provided with a display for displaying the number of printed sheets, a mode setting switch, etc., and an attached memory card. 42
A card interface 43 for reading and writing data, a paper sensor 44 for detecting paper jam, the fan 15, and an interface 45 for receiving image information from the host computer are connected to the computer.

The interlock switch 16 connects the DC power supply 17 to the motor drive circuit 36 and the laser scanner unit 5.
, 24 connected to the high voltage power supply circuit 37 and the fan 15
It is inserted into the V supply line, and when the housing of the printer main body 21 is opened, it is detected and the 24Y supply line is cut off.

The CPU 31, ROM B 2, RAM 33 and I1
+5V is supplied to the 0 port 34 from the DC power supply 17.

The memory card 42 is provided corresponding to the drum unit 2, and stores the print/sheet number A and the print limit number B corresponding to the life of the photosensitive drum 3 included in the drum unit 2, as shown in FIG. It has a memory area for (storage means).

When the power switch (not shown) of the device of this embodiment is turned on and the predetermined initialization process is completed, the CPU 3
1 starts the main routine according to the program stored in the ROM 32. The program is controlled to execute the printing determination process shown in FIG. 5 at appropriate times within this main routine.

In other words, when it comes time to execute the print determination process, C
The PU 31 first determines whether or not the print start state is set. If the print start state has not been set, the process immediately returns to the main routine.

On the other hand, when the print start state is set by a print command from the host computer, the card interface 43 is controlled to print the print number data A and print limit recorded in the memory card 42 attached to the interface 43. Read the sheet count data B and compare both data (comparison means). And this number of printed sheets A is the limit number of sheets 8
If the number is less than 1, the print number data A recorded in the memory card 42 is updated by one count, and a print routine is executed (print execution control means). That is, in accordance with the electrophotographic process, the charger 4, laser control circuit 22, developer 6, and transfer charger 7 are sequentially operated to print image information sent from the host computer onto paper.

On the other hand, if the number of printed sheets A matches the limit number of sheets B, a message prompting the replacement of the photosensitive drum 3 is displayed on the display provided on the operation unit 41, and the transition to the printing routine is stopped. , returns to the main routine (printing prohibition control means). In addition, if the number of printed sheets A or the limit number B is exceeded, the recorded information in the memory card 42 is abnormal, so this is displayed on the display, the transition to the printing routine is prohibited, and the main routine is returned. return.

In this embodiment configured as described above, when replacing the drum unit 2 with a new one, the memory card 42 provided corresponding to the drum unit 2 is attached to the card interface 4-3.

At this time, since the corresponding drum unit 2 is unused, the memory card 42 has "0" as the print number data A.
are recorded. Furthermore, as the print limit number data B, the photosensitive drum 3 included in the drum unit 2 is
The print limit number is set according to the sensitivity characteristics of the printer.

In this state, when the power switch is turned on and printing operation is started by a print command from the host computer, the print number data A in the memory card 42 is updated by 1 count each time one image is printed. . Then, the printing operation using the photosensitive drum 3 is permitted until the print number data A reaches the print limit number data B set in the memory card 42 in advance. On the other hand, when the printing number data A matches the printing limit number data B, it is determined that the photosensitive drum 3 has reached the end of its life, the printing operation is prohibited, and a message prompting the replacement of the photosensitive drum 3 is displayed on the display of the operation unit 41. be done. Therefore, the operator replaces the photosensitive drum 3 and the drum unit 2 with a new one in accordance with the displayed contents. At this time, the drum unit 2
A memory card 42 corresponding to the previous drum unit 2 is prepared and attached to the card interface 43 in place of the memory card 42 corresponding to the previous drum unit 2. For the newly loaded memory card 42, a print limit number is set according to the sensitivity characteristics of the photosensitive drum 3 included in the corresponding new drum unit 2. Therefore, this time the memory card 42
The lifespan of the drum unit 2, that is, the photosensitive drum 3, is determined based on the print limit number of sheets.

As described above, in this embodiment, a memory card 42 having a storage area for print number data A and print limit number data B is provided corresponding to the drum unit 2 which is detachably attached to the printer main body 1. A print limit number of sheets determined empirically is set according to the sensitivity characteristics of the photosensitive drum 3 included in the drum unit 2. In addition, each time a printing operation is executed, the memory card 4 is
2, the number of printed sheets is counted and stored. If the counted and stored number of printed sheets matches the limit number of printed sheets, it is determined that the life of the photosensitive drum 3 has come to an end, and the printing operation is prohibited. Therefore, the lifespan of the photosensitive tram 3 is determined by the life of the memory card 4.
It can be changed by setting the print limit number stored in 2. That is, in general, the sensitivity characteristics and the degree of deterioration thereof of the photosensitive drums 3 vary depending on the photosensitive drums 3, and the printing limit number can be arbitrarily set for each photosensitive drum 3 in consideration of this variation. As a result, the photosensitive drum 3
It is possible to prevent the problem of printing operation continuing with deterioration of printing quality after the life of the photosensitive drum 3 has passed, and also to eliminate the waste of replacing the photosensitive drum 3 that still has good sensitivity. Usage efficiency can be improved.

Note that the present invention is not limited to the above embodiments.

For example, in the embodiment described above, the memory card 42 is used as a storage means.
is shown as an example, but the present invention is not limited to this, and other recording media such as magnetic tape may also be used. Also, RAM, ROM, and E2FROM with power backup
You may use a semiconductor memory such as . Furthermore, the present invention is not limited to laser printers, but can also be applied to copying machines, etc., in which a drum unit including a photoreceptor can be detachably attached to the main body of the apparatus. It goes without saying that various other modifications can be made without departing from the gist of the present invention.

[Effects of the Invention] As detailed above, according to the present invention, the print limit number of the photoconductor can be arbitrarily set according to the sensitivity characteristics of the photoconductor, and deterioration in print quality due to the life of the photoconductor can be prevented. Therefore, it is possible to provide an electrophotographic apparatus that can improve the usage efficiency of a photoreceptor.

[Brief explanation of drawings]

The figures show an embodiment in which the present invention is applied to a laser printer, in which Fig. 1 is an overall configuration diagram, Fig. 2 is a configuration diagram of a laser scanner unit, and Fig. 3 is a block diagram showing the entire circuit configuration. Figure 4 is the main memory configuration diagram of the memory card, Figure 5
The figure is a flowchart showing a print determination processing routine in the CPU. 2...Drum unit, 3...Photosensitive drum, 4...
Charger, 5... Laser scanner unit, 6... Developer, 7
...Transfer charger, 31...CPU. 42...Memory card (storage means).

Claims (1)

[Scope of Claims] A charging section, an exposure control section, a developing section, and a transfer section are arranged around a rotationally driven photoconductor according to an electrophotographic process, and a drum unit including at least the photoconductor is freely attachable to and detachable from an apparatus main body. In the electrophotographic apparatus, the storage means is provided corresponding to the drum unit and stores print number data and print limit number data corresponding to the life of the photoreceptor included in the drum unit, and when printing is started, the storage means Comparison means for comparing the stored print number data and print limit number data, and when it is determined by the comparison means that the print number data is less than the print limit number data, a printing operation is performed and only for the number of prints is performed. printing execution control means for updating the number of printed sheets data stored in the storage means; and printing prohibition control for prohibiting printing operation when the comparison means determines that the number of printed sheets data matches the limit number of printed sheets data. An electrophotographic apparatus characterized by comprising: means.