JP3869921B2 - Electrophotographic image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic image forming apparatus in which a process cartridge is detachable and forms an image on a recording medium using an electrophotographic image forming system such as a printer (laser beam printer, LED printer, etc.) or an electrophotographic copying machine. About.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus using an electrophotographic image forming process, an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member are integrally formed into a cartridge, and the cartridge is electrophotographic image forming apparatus. A process cartridge system that can be attached and detached is employed. According to this process cartridge system, the apparatus can be maintained by the user himself / herself without depending on the service person, so that the operability can be remarkably improved. Therefore, this process cartridge system is widely used in electrophotographic image forming apparatuses.
[0003]
The process cartridge is a cartridge in which charging means or cleaning means, developing means and electrophotographic photosensitive member are integrated. The cartridge can be detachably attached to the electrophotographic image forming apparatus main body, or at least one of charging means and cleaning means, a developing means and an electrophotographic photosensitive member are integrally formed into a cartridge to form an electrophotographic photosensitive member. The electrophotographic photosensitive member and the cleaning means are integrated into a cartridge so that the electrophotographic image forming apparatus main body can be attached and detached.
[0004]
In recent years, an electrophotographic image forming apparatus of a type in which a nonvolatile memory is mounted on a process cartridge, various information is stored, and communication with the apparatus main body is used.
[0005]
However, in the electrophotographic image forming apparatus as described above, even if the communication memory between the non-volatile memory mounted in the process cartridge and the image forming apparatus main body is not checked for an abnormality or a communication abnormality check is performed. Information on communication abnormality is not reported to the outside.
[0006]
In addition, some types of apparatuses that check for communication errors with a nonvolatile memory employ a method that also uses the detection of the process unit based on detection of communication errors.
[0007]
[Problems to be solved by the invention]
Accordingly, the present invention is a further development of the electrophotographic image forming apparatus as described above.
[0008]
Accordingly, a main object of the present invention is to provide an electrophotographic image forming apparatus that can accurately and in detail detect abnormality of the image forming apparatus and has good usability.
[0009]
Another object of the present invention is to provide an electrophotographic image forming apparatus capable of detecting an abnormality in communication between a nonvolatile memory provided in a process cartridge and the apparatus main body.
[0010]
Another object of the present invention is to provide an electrophotographic image forming apparatus capable of notifying the outside when an abnormality is detected in communication between the nonvolatile memory provided in the process cartridge and the apparatus main body. It is to be.
[0011]
Another object of the present invention is to provide an electronic photograph that can accurately detect when the process cartridge is not properly mounted and when there is an abnormality in communication between the nonvolatile memory provided in the process cartridge and the apparatus main body. An image forming apparatus is provided.
[0012]
[Means for Solving the Problems]
The above object is Ru is achieved by the image forming apparatus according to the present invention.
[0014]
In summary, according to the present invention, in an electrophotographic image forming apparatus for detaching a process cartridge and forming an image on a recording medium,
(A) mounting means for detachably mounting a process cartridge having an electrophotographic photosensitive member , developing means for developing an electrostatic latent image formed on the electrophotographic photosensitive member , and a nonvolatile memory;
(B) a developing bias output unit operable to output a developing bias to the developing means,
(C) when the applied said developing bias to said developing means from a developing bias output unit, a cartridge detecting means for outputting different signals depending on the presence or absence of the process cartridge,
(D) means for communicating with the non-volatile memory;
(E) a communication abnormality detecting means for detecting presence / absence of an abnormality in communication with the nonvolatile memory by the communication means;
(F) When the cartridge detection unit outputs a signal indicating the presence of the process cartridge, and when an abnormality is detected by the communication abnormality detection unit, the determination unit determines that there is a communication abnormality with the nonvolatile memory. And having
(G) When the cartridge detection unit outputs a signal indicating the absence of the process cartridge , the determination unit detects an abnormality in communication with the nonvolatile memory by the communication abnormality detection unit, and the communication abnormality When it is detected by the detection means that there is no abnormality in communication, it is determined that the development bias output means is abnormal or the cartridge detection means is abnormal , and the communication abnormality detection means detects an abnormality in communication. In this case, an electrophotographic image forming apparatus is provided in which it is determined that there is no process cartridge .
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the electrophotographic image forming apparatus according to the present invention will be described in more detail with reference to the drawings.
[0016]
Example 1
A first embodiment of the present invention will be described with reference to FIGS.
[0017]
FIG. 2 is a block diagram of an electrophotographic image forming apparatus (laser beam printer) 101 according to the present invention.
[0018]
In FIG. 2, the laser beam printer 101 has a cassette 201 for storing the recording paper S, a pickup roller 202 for picking up the recording paper S from the cassette 201, and a paper feeding roller 203 for feeding the picked up recording paper S are provided. It has been. A conveyance roller 204 that conveys the fed recording paper S to a registration roller 205 described later is disposed downstream of the paper supply roller 203. A registration roller 205 that synchronously conveys the recording paper S is disposed downstream of the conveyance roller 204.
[0019]
Downstream of the registration roller 205, a process cartridge 206 is detachably disposed on the printer main body by a mounting means 220. The process cartridge 206 includes a photosensitive drum 208 that forms an electrostatic latent image upon receiving laser light from the laser scanner unit 211, a charger 207 that primarily charges the photosensitive drum 208, a photosensitive drum 208 that forms an electrostatic latent image, and a photosensitive drum. A charging unit 207 that primarily charges 208, a developing unit 209 that visualizes the electrostatic latent image by applying toner, and a toner storage unit.
[0020]
The user can replace the process cartridge 206 when the toner in the process cartridge 206 runs out or the photosensitive drum 208 reaches the end of its life.
[0021]
In addition, a transfer roller 210 for transferring the toner on the photosensitive drum 208 to the sheet is disposed across the photosensitive drum 210 and the conveyance path.
[0022]
Further, a fixing device 212 is disposed downstream of the transfer roller 210, and a fixing paper discharge roller 213 is disposed downstream of the fixing device 212. Further, FD (face-down) paper discharge transport rollers 214, 215, and 216 are disposed downstream of the fixing paper discharge roller 213 to transport the recording paper to the FD paper discharge tray 217.
[0023]
FIG. 1 is a block diagram showing the functional configuration of this embodiment.
[0024]
The laser beam printer 101 includes a main body main controller 102 that controls the main body. The main controller 102 is composed of a CPU, a ROM, a RAM, a gate element, and the like, and a main part of control is realized by software written in the ROM.
[0025]
The main body main controller 102 is connected to the external device 104 via the external interface 111 and the cartridge memory unit 103 via the cartridge memory interface 112. Further, the high voltage unit 5 and the main motor unit 6 are connected through a signal line.
[0026]
The main controller 102 includes a communication abnormality detection unit 105, a cartridge communication unit 106, and an external device communication unit 107.
[0027]
The cartridge memory unit 103 is provided in the cartridge 206 and includes a main body communication unit 109 and a memory main body 108.
[0028]
Further, a communication data analysis unit 110 is provided in the communication abnormality detection unit 105.
[0029]
Next, functions of the above-described units will be described.
[0030]
The main body communication means 109 of the cartridge memory unit 103 communicates with the main body main control device 102 via the cartridge memory interface 112 to write the data sent from the main body main control device 102 to the memory main body 108, and the data in the memory main body 108. Is output to the main body main control unit 102. The memory main body 108 is a storage area for various information relating to the cartridge, and a nonvolatile memory is used.
[0031]
The cartridge communication means 106 of the main controller 102 controls the writing and reading of information to and from the cartridge memory section 103 via the interface 112 with the cartridge memory section 103. I do.
[0032]
The external device communication unit 107 controls communication with the external device 104 via the interface 111. The main body main controller 102 outputs cartridge communication abnormality information, which will be described later, to the external device 104 via the external device communication means 107.
[0033]
The communication abnormality detection unit 105 checks communication abnormality between the main body main control unit 102 and the cartridge memory unit 103 based on the analysis result by the communication data analysis unit 110.
[0034]
The communication data analysis unit 110 analyzes the data received from the cartridge memory unit received from the cartridge communication unit 106. In this embodiment, a checksum of all data read from the memory body 108, that is, a total value of all data is calculated.
[0035]
The communication abnormality detection means 105 compares the checksum obtained by the communication data analysis means 110 with the read value of the checksum stored at a predetermined location in the memory main body 108 to check the success or failure of communication. Since these checking methods are well known, they will not be described in detail. Further, in the present invention, the communication abnormality detection method need not be the method shown in this embodiment. When the communication data analysis means detects a communication abnormality by checking the communication result, it outputs cartridge communication abnormality information to the external apparatus 104 via the external apparatus communication means 107.
[0036]
With the configuration of this embodiment, when a communication error occurs between the nonvolatile memory mounted on the process cartridge of the laser beam printer and the apparatus main body, the external device is notified of this, and the operator takes action according to the situation. The usability of the image forming apparatus and the entire system using the image forming apparatus can be improved.
[0037]
Example 2
In the first embodiment, communication abnormality between the main body main controller and the cartridge memory unit is only checked without any particular condition.
[0038]
However, as described above, the process cartridge can be easily removed by the user, and the user may operate the laser beam printer while forgetting to attach the process cartridge. In such a case, if the communication check is performed unconditionally as in the first embodiment, the communication abnormality detecting means notifies the cartridge communication abnormality information to the external device.
[0039]
Therefore, in the second embodiment, only the cartridge presence / absence detection means is provided in the printer main body in addition to the communication abnormality detection means, and only when it is determined that the process cartridge is normally set as a result of the check by the cartridge presence / absence detection means, The cartridge communication means communicates with the cartridge memory, and the communication abnormality detection means checks the communication abnormality.
[0040]
This embodiment will be specifically described below with reference to the block diagram of FIG.
[0041]
The laser beam printer shown in this embodiment has the same configuration as that of the first embodiment shown in FIG.
[0042]
FIG. 3 shows the functional configuration of this embodiment. In the figure, the elements denoted by reference numerals 302 to 304 and 306 to 312 are the same as the elements denoted by reference numerals 102 to 104 and 106 to 112 of the first embodiment, and thus description thereof is omitted.
[0043]
In the first embodiment, the main body main controller 101 (302) has the communication abnormality detection means 105, but in this embodiment, it has the cartridge abnormality detection means 305.
[0044]
The cartridge abnormality detection unit 305 includes a communication data analysis unit 310 and a cartridge presence / absence detection unit 313, and the main body main controller 302 further includes a development high-voltage output unit 314.
[0045]
The communication data analysis unit 310 has the same function as the communication data analysis unit 110 of the first embodiment. The development high voltage output means 314 applies a development high voltage to the developing device 209 of the process cartridge 206 and an antenna (not shown) for detecting the remaining amount of toner in the toner container 315. The development high voltage application timing is given by a laser beam printer state management means (not shown).
[0046]
When developing high voltage is applied, the cartridge presence / absence detection means 313 returns signals of different levels depending on the remaining amount of toner and the presence / absence of the cartridge from the antenna of the toner container 315. In this way, the cartridge presence / absence detection means 313 determines the presence / absence of a cartridge based on the signal level when a development high voltage is applied. The configuration of the cartridge presence / absence means is well known and will not be described in detail. In the present invention, the detection method for the presence / absence of a cartridge need not be the method shown in this embodiment.
[0047]
The cartridge abnormality detection unit 305 notifies the external device 304 of the cartridge presence / absence information obtained by the cartridge presence / absence detection unit 313 via the cartridge communication unit 306 and the external device communication unit 307. Also, the cartridge abnormality detection means 305 determines whether or not to detect a communication abnormality with the cartridge based on the information.
[0048]
FIG. 4 shows a flowchart of the control of the cartridge communication means 306 in this embodiment.
[0049]
First, it is confirmed whether or not the cartridge is in an indefinite state, that is, whether or not the process cartridge 206 is detachable by the user (step 401 (hereinafter referred to as “S401”)). The laser beam printer 101 according to the present embodiment has a structure in which a predetermined door is opened when the cartridge is attached / detached, and the opening / closing of the door can be detected by a sensor (not shown). Therefore, the open state of the door is determined as the cartridge indefinite state. If the cartridge is not in an indefinite state, the cartridge presence / absence determination unit 313 determines the cartridge presence / absence determination result (S402).
[0050]
If there is no cartridge in S402, the process returns to S401. If there is a cartridge in S402, cartridge communication is started (S403).
[0051]
Thereafter, it is checked whether the cartridge is in an indefinite state, that is, whether the door is not open (S404). If the cartridge is in an indefinite state, a predetermined communication end process is performed (S405), and the process returns to S401.
[0052]
FIG. 5 shows a flowchart of control of the cartridge abnormality detecting means 305 in this embodiment.
[0053]
First, the cartridge undefined state check similar to S401 is performed (S501), and if the cartridge undefined state is lost, it is checked whether there is a cartridge (S502). Here, if it is determined that there is no cartridge based on the information from the cartridge presence / absence detection means 313, the absence of the cartridge is confirmed and notified to the outside (S505). If it is determined in S502 that there is a cartridge, a cartridge communication check is started (S503). If it is determined that the cartridge communication is abnormal (S504), the cartridge communication abnormality is notified to the outside (S506). If it is determined in S504 that the cartridge communication is not abnormal, the process directly returns to S501.
[0054]
As described above, the abnormality information regarding the cartridge can be checked in detail by detecting the presence / absence of the cartridge and detecting the communication abnormality with the cartridge memory.
[0055]
Example 3
In the second embodiment, when it is determined that there is no cartridge, communication with the cartridge memory and communication abnormality check are not performed. However, in the third embodiment, even when it is determined that there is no cartridge. The communication with the cartridge memory is performed to detect the abnormality of the function related to the presence / absence of the cartridge.
[0056]
The laser beam printer shown in this embodiment has the same configuration as that of the first embodiment shown in FIG. The functional configuration of the present invention is the same as that of FIG. 3 of the second embodiment.
[0057]
However, the cartridge communication unit 306 communicates with the cartridge memory 303. In addition to the checksum check as in the first and second embodiments, the communication data analysis unit 310 also checks whether predetermined data is written in a constant area in the write data.
[0058]
Then, the cartridge abnormality detection means 305 determines the abnormality of the function relating to the presence / absence of the cartridge by the control shown in the flowchart of FIG. Hereinafter, the control of the cartridge abnormality detecting means 305 in this embodiment will be described with reference to FIG.
[0059]
First, a cartridge indefinite state check is performed (S601), and if the cartridge is not in an indefinite state, it is checked whether there is a cartridge (S602). If it is determined that there is a cartridge based on the information from the cartridge presence / absence detecting means 313, a cartridge communication check is started (S603). If it is determined in S604 that the cartridge communication is abnormal, the cartridge communication abnormality is notified to the outside (S605). If it is determined in S604 that there is no cartridge communication abnormality, the process directly returns to S601.
[0060]
On the other hand, even if it is determined that there is no cartridge in S602, a cartridge communication check is started (S606), and it is confirmed whether there is a communication abnormality (S607). Here, as described above, the communication data analysis unit 310 performs a checksum check and a check as to whether predetermined data is written in the constant area of the memory. Therefore, when the process cartridge is not set normally, an error can be detected because the constant data cannot be read. If it is determined that the communication is abnormal, the absence of the cartridge is notified to the outside (S608).
[0061]
If it is determined in step S607 that there is no communication abnormality, the development high-voltage output unit or the cartridge presence / absence detection unit is informed of the abnormality (S609).
[0062]
As described above, in this embodiment, the abnormality information relating to the cartridge and the high-voltage output system can be checked in detail by detecting the presence or absence of the cartridge and detecting the communication abnormality with the cartridge memory.
[0063]
【The invention's effect】
As described above, according to the electrophotographic image forming apparatus of the present invention, even when the cartridge detection unit outputs a signal indicating that there is no process cartridge, the communication abnormality detection unit detects an abnormality in communication with the nonvolatile memory. Thus, based on the detection result, the presence / absence of the process cartridge, the abnormality in communication with the cartridge memory, and the abnormality in the development high-voltage output system can be accurately determined , and the usability can be improved.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a functional configuration of a first embodiment of the present invention.
FIG. 2 is a schematic configuration diagram of a laser beam printer embodying the present invention.
FIG. 3 is a block diagram showing a functional configuration of second and third embodiments of the present invention.
FIG. 4 is a flowchart of control of cartridge communication means of the second embodiment.
FIG. 5 is a flowchart of the control of the cartridge abnormality detecting means of the second embodiment.
FIG. 6 is a flowchart of the control of the cartridge abnormality detecting means of the third embodiment.
[Explanation of symbols]
101 Laser beam printer 102, 302 Main unit main control device 103, 303 Cartridge memory unit 104 External device 105 Communication abnormality detection unit 106, 306 Cartridge communication unit 107, 307 External device communication unit 108, 308 Memory main unit 109, 309 Main unit communication unit 110 310 Communication data analysis means 206 Process cartridge 305 Cartridge abnormality detection means 313 Cartridge presence / absence detection means 314 Development high voltage output means

Claims (1)

In an electrophotographic image forming apparatus for detaching a process cartridge and forming an image on a recording medium,
(A) mounting means for detachably mounting a process cartridge having an electrophotographic photosensitive member , developing means for developing an electrostatic latent image formed on the electrophotographic photosensitive member , and a nonvolatile memory;
(B) a developing bias output unit operable to output a developing bias to the developing means,
(C) when the applied said developing bias to said developing means from a developing bias output unit, a cartridge detecting means for outputting different signals depending on the presence or absence of the process cartridge,
(D) means for communicating with the non-volatile memory;
(E) a communication abnormality detecting means for detecting presence / absence of an abnormality in communication with the nonvolatile memory by the communication means;
(F) When the cartridge detection unit outputs a signal indicating the presence of the process cartridge, and when an abnormality is detected by the communication abnormality detection unit, the determination unit determines that there is a communication abnormality with the nonvolatile memory. And having
(G) When the cartridge detection unit outputs a signal indicating the absence of the process cartridge , the determination unit detects an abnormality in communication with the nonvolatile memory by the communication abnormality detection unit, and the communication abnormality When it is detected by the detection means that there is no abnormality in communication, it is determined that the development bias output means is abnormal or the cartridge detection means is abnormal , and the communication abnormality detection means detects an abnormality in communication. In this case, it is determined that the process cartridge is not present .

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