JP4495232B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to a process cartridge and an image forming apparatus such as an electrophotographic copying machine, a laser printer, and a facsimile machine to which the process cartridge can be attached and detached.

Conventionally, in an image forming apparatus using an electrophotographic image forming process, the process means acting on the electrophotographic photosensitive member and the previous electrophotographic photosensitive member are integrally formed into a cartridge, and the cartridge can be attached to and detached from the image forming apparatus main body. The process cartridge method is adopted.
Such a process cartridge normally has a lifetime when the prefilled toner is consumed and a normal image cannot be printed. Here, several techniques for detecting the remaining amount of toner have been reported as toner detection means.

For example, Patent Document 1 reports a technique that indicates the amount of toner used or the remaining amount of toner by integrating image signals.
Further, for example, in Patent Document 2, in an image forming apparatus using a process cartridge, a process cartridge replacement time is warned with high accuracy. In addition, there has been reported a technique for determining whether or not to continue the printing operation using the memory in the apparatus when the memory in the process cartridge is inaccessible.

  However, the life of the process cartridge in the image forming apparatus, that is, the toner remaining amount detecting means is not a sequential remaining amount detection that always displays the remaining amount as a general one, but a stepwise remaining amount detection. However, in recent years, a cartridge having a longer life has been commercialized, and a cartridge with better usability has been desired. A cartridge capable of displaying the remaining amount of toner at any time as well as when the amount of toner becomes less than a predetermined amount remains. It is desired. However, with this technique, it is necessary to count all image signals for one page. For example, in the case of a 1200 dpi printer, a maximum of 69 million dots or more is counted on one page of A3 size recording paper. There is a problem that the scale of the control circuit becomes large. In addition, since there is a large difference in the count start timing and the count time depending on the size of the recording paper to be printed, there is a problem that the reliability when determining the toner usage and remaining amount detection is lowered.

  Also, an image forming apparatus having a recyclable removable process cartridge in which process essential devices such as a photosensitive member, a charging roller, a cleaning unit, a waste toner collecting unit, a developing unit, and a toner storage unit are unitized. Conventionally, a process cartridge has a single memory and stores data by exchanging with the main body memory. However, data may be lost due to a failure of an electronic component such as a memory. Further, since the main body memory stores all information such as process cartridges used in the past, it is very necessary to read and write data every time data is updated in an accessible state.

Japanese Patent Laid-Open No. 10-247012 Japanese Patent Laid-Open No. 09-120237

  Therefore, the present invention has been made in view of the above problems, and the problem is that the lifetime of the photoconductor can be determined by integrating the image signals, and the lifetime of the process cartridge can be determined. An image forming apparatus is provided. It is another object of the present invention to provide an image forming apparatus that prevents data from being lost due to a failure of an electronic component or the like in a process cartridge.

In order to achieve the above object, the image forming apparatus of the present invention is selected from a photosensitive member, a charging roller, a cleaning unit, a waste toner collecting unit, a developing unit, and a toner storage unit in an image forming apparatus in which a process cartridge can be mounted. At least one unit is unitized, and a recyclable removable process cartridge and a range that matches the minimum recording paper size , and the count start timing of the image signal amount is always constant at the center of the image area After that, the image signal amount is counted and integrated, and the image forming apparatus includes a life determination unit that determines the life of the photoconductor based on the value obtained by the integration.
The image forming apparatus according to the present invention further includes a first memory in the image forming apparatus main body, and the process cartridge holds the second memory for backup. The image forming apparatus can store data in the memory.
The image forming apparatus of the present invention is further an image forming apparatus in which the process cartridge has a plurality of backup memories.
The image forming apparatus of the present invention is further an image forming apparatus that limits the timing of writing data to the first memory.
The image forming apparatus of the present invention is further an image forming apparatus that informs the user that any memory is defective.

As described above, in the image forming apparatus according to the present invention , the photosensitive device, the charging roller, the cleaning unit, the waste toner collecting unit, the developing unit, the toner storing unit, and the like main process devices are unitized. In an image forming apparatus having a detachable process cartridge that can be recycled, a memory for backup is provided in the process cartridge in addition to the main body memory and the process cartridge memory. Even if there is, you can save without losing data.
In the image forming apparatus of the present invention, by limiting the timing of accessing the main body memory, the possibility of adversely affecting data storage due to an access error or the like is reduced, so that data storage can be performed safely.
In the image forming apparatus according to the present invention, if any of the second or third memory or both of the memories is inadequate, it is possible to confirm that the defect has occurred in the memory by notifying the user of the purpose. , Can prompt the exchange.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.

FIG. 1 is a schematic diagram showing the internal configuration of an image forming apparatus according to an embodiment of the present invention. The image forming apparatus 5 includes a detachable process cartridge 2 , and the process cartridge 2 further includes a photoconductor 11, a charging roller 3, a cleaning unit and waste toner collecting unit 6, a developing unit and a toner storage unit 4. Is done. The optical system 1 includes a polygon motor, a polygon mirror, an Fθ lens, a laser diode, a mirror, and the like. The recording paper 9 stored in the paper feed cassette 8 by the paper feed roller 7 is conveyed to the photoconductor 11. The photosensitive member 11 is driven to rotate in the clockwise direction. At that time, the surface is charged by the charging roller 3, and a laser beam is irradiated from the optical system 1 to form an electrostatic latent image on the photosensitive member 11 . This latent image is visualized by toner when passing through the developing means and the toner storage unit 4. This visible image is transferred to the recording paper 9 conveyed to the photosensitive member 11 by the transfer roller 10, and then conveyed to the fixing roller 12, and the visible image on the recording paper 9 is fixed, and then to the outside of the image forming apparatus 5 . The paper is ejected.

FIG. 2 is a block diagram of the present invention. FIG. 3 shows a perspective view of the process cartridge 2 of the present invention. A substrate 13 (only the connector portion shown) on which the cartridge memory 17 is mounted is mounted on the process cartridge. The process cartridge 2 provided with non-volatile memory (hereinafter cartridge memory) 17, and can read and written by the CPU14 on the image forming equipment 5. The image forming apparatus 5 includes a ROM 15 and a RAM 16 as memories for storing software, programming data, and the like. The CPU 14 performs printing by operating various components including the main motor 20 of the image forming apparatus 5 in an integrated manner. The counter and arithmetic circuit 18 has a function of counting and calculating the image signal output from the CPU 14 and writing the result in the cartridge memory 17 as needed. The LD (laser diode) 19 controls the lighting state according to the image signal.

The functions of the counter and arithmetic circuit 18 in FIG. 2 will be described. The counter and arithmetic circuit 18 has a function of counting the image signals output from the CPU 14 as described above, but does not count all the image signals, but has a function of counting only within an area having a predetermined width.
FIG. 4 shows a simple timing chart. This figure shows the timing in the main scanning direction (horizontal direction), and A is a synchronizing signal in the main scanning direction, and indicates the start position of each print line. In FIG. 4, three lines are displayed as an example. B is an image signal output from the CPU. The output starts after t1 sec after A rises, and is output for t2 sec. C is a signal that characterizes the present invention, and is a signal that rises t3 seconds after A rises and then falls after t4 seconds. The counter 18 counts while C rises (hereinafter referred to as an effective area of C). When C falls (when the effective area ends), the counter stops and holds the value at that time. The second line and the third line are similarly counted, and the count values are accumulated. D shows how the count values of the image signals in the effective area of C are integrated.
The accumulated count value is multiplied by a coefficient calculated according to the pixel density and density, and the resulting value is written in the cartridge memory. On the other hand, the ROM in the image forming apparatus main body stores the value of the number of image signals that represents the life of the photoconductor. As the number of image signals corresponding to the photoconductor lifetime, a value obtained in advance through experiments and statistically is stored.

The CPU reads out the accumulated value written in the cartridge memory 17, which was compared with the value stored in the ROM, the integrated value of the cartridge memory 17 of the photosensitive member 11 when it reaches the value stored in the ROM Judge that it is a lifetime. The effective area of C has a constant width regardless of the size of the recording paper to be printed. Usually, the maximum recording paper width printed by a laser printer is 420 mm in the A3 side and the minimum recording paper width is 100 mm in the postcard made by the government, but the minimum width is used in the present invention. Further, the area is t3 sec after the rise of the synchronizing signal in the main scanning direction (in the case of FIG. 4), and is located almost at the center of the image area. That is, even when A3 recording paper is printed, the image signal is counted only in the central postcard width area at the center.
This is based on the grounds that it is unlikely that there is a printing method in which the image in the center of the image area is blank, and the lifetime of the photoconductor 11 can be estimated by adding only the number of image signals in the minimum area in the center. It is a method based on this.
By the method described above, it is possible to know an appropriate replacement time of the photoconductor 11 .

In the present invention, the life of the photoconductor 11 is determined by counting the amount of image signals only within a range that matches the minimum recording paper size, thereby reducing the size of the photoconductor life determination circuit such as a counter.
In addition, since the timing at which the count is started is always constant for each horizontal line, the reliability for determining the lifetime becomes higher than in the past.

As another embodiment of the present invention, when either the usage amount of the photoconductor 11 obtained based on the rotation time of the photoconductor 11 or the integrated value of the image signal amount described above reaches a predetermined value first. The life of the photoconductor 11 is determined. Means for determining the amount of the original to the photoreceptor 11 the rotation time of the photosensitive member 11 is a well-known technique, details are not described, the amount of the photosensitive member 11 obtained is written to the cartridge memory 17. The amount to be photoconductor life is stored in the ROM in the five-vivo imaging equipment, the amount used written to the cartridge memory 17 is in the life of the photosensitive member 11 when reaching this value To be judged.
On the other hand, the image forming equipment 5 are got together life determination means photoreceptor 11 based on the above-described embodiment, the photosensitive if any of the determination means has reached a predetermined value stored in ROM previously The life of the body 11 is determined.

Thus, by combining the technique described in one embodiment as a means for determining the life of the photoreceptor 11 with the technique determined from the usage amount of the photoreceptor 11 obtained based on the rotation time of the photoreceptor 11 , The accuracy of determining body life and determining the appropriate replacement time is even higher.

FIG. 5 is a block diagram for controlling the operation of the present invention. The image forming apparatus 5 includes a ROM 15, a RAM 16, and a nonvolatile memory (hereinafter referred to as a main body memory) 17 as memories for storing software, programming data, and the like. The CPU 14 performs printing by operating various components of the image forming apparatus 5 in an integrated manner. Further, the process cartridge 2 includes a second memory 17a and a third memory 17b (for backup), which can be read and written by the CPU 14 of the image forming apparatus 5, and is always accessible.

FIG. 6 is a flowchart showing the procedure for writing to the main body memory 16. For example, when the toner has run out of the process cartridge 2, when the access to the main memory 17, at which time, a brief can be determined from the CPU 14, 2 Tsunomemo Li 17a of the process cartridge 2, the correctness and 17b data Is written (a). Next, the written data is read again by the CPU 14 and compared with the original data sent earlier (b). From either one of the memory 17a, when the 17b or we sent data matches the original data, and writes the normal memory 17a, the data stored in 17b in the main body memory 17 (e) . If both of the data, if it does not match the original data, both the memory 17a, because 17b might have failed, by prohibiting writing of data into the main memory 17, mis information can be prevented from being stored in the main body memory 17.

1 is a schematic diagram illustrating an internal configuration of an image forming apparatus according to an embodiment of the present invention. It is a block diagram of the present invention. It is a figure which shows the perspective view of the process cartridge 2 of this invention. It is a figure which shows a simple timing chart. It is a block diagram which controls operation | movement of this invention. It is a flowchart which shows the write-in procedure to a main body memory.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical system 2 Process cartridge 3 Charging roller 4 Developing means and toner storage part 5 Image forming apparatus 6 Cleaning means and waste toner collection part 7 Paper feed roller 8 Paper feed cassette 9 Recording paper 10 Transfer roller 11 Photoconductor 12 Fixing roller 13 Substrate 14 CPU
15 ROM
16 RAM
17 Cartridge memory (nonvolatile memory)
17a Second memory 17b Third memory 18 Arithmetic circuit 19 LD
20 Main motor

Claims (5)

In an image forming apparatus to which a process cartridge can be attached,
At least one selected from a photoconductor, a charging roller, a cleaning unit, a waste toner collecting unit, a developing unit, and a toner storage unit is unitized, and a detachable process cartridge that can be recycled;
The image signal amount is counted and integrated within a range that matches the minimum recording paper size and the image signal amount count start timing is always constant at the center of the image area. An image forming apparatus comprising: a life determining unit that determines the life of the photoconductor based on the measured value. A first memory is provided in the image forming apparatus main body,
By holding the second memory for backup in the process cartridge,
The image forming apparatus according to claim 1, wherein data can be stored in the other memory even if any one of the memories is defective. The image forming apparatus according to claim 1, wherein the process cartridge includes a plurality of backup memories. 4. The image forming apparatus according to claim 1, wherein a timing for writing data to the first memory is limited. 5. The image forming apparatus according to claim 1, wherein a user is notified that a defect has occurred in any of the memories.

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