JPH09114334A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a user from getting into a dangerous situation caused by fault and breakage due to use exceeding the working limit of a cartridge. SOLUTION: This device is provided with the cartridge 12, a new cartridge detecting means 15, a means 14 for counting the number of using times of the cartridge 12, a means 16 for counting the number of recycling times of the cartridge 12, and a high voltage power source 17. In such a case, it is equipped with a means 13 judging whether the cartridge 12 exceeds the working limit and masking a trigger signal to the high voltage power source 17 in the case the cartridge 12 exceeds the working limit.

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 such as a copying machine, a printer or a facsimile having a cartridge which can be attached to and detached from a main body.

[0002]

2. Description of the Related Art Conventionally, in image forming apparatuses such as laser printers, process cartridges and the like have been disposable, but in recent years, recyclable process cartridges have been developed in view of environmental protection and ecology. The process cartridge is detachable from the main body of the image forming apparatus, constitutes a part of the image forming apparatus, and executes at least a part of the image forming process. A voltage of several hundreds to several thousands of V is usually applied from a high voltage power source to the process cartridge and its periphery.

There are various approaches to the recyclable design of the process cartridge, such as making the parts constituting the process cartridge recyclable and refilling only the contents of the process cartridge. For example, a process cartridge that integrates a toner cartridge, a developing unit, a cleaning unit, etc. usually runs out of toner in the toner cartridge before the life of the photoconductor or the like, so the toner in the toner cartridge must be replaced when the process cartridge is replaced. The process cartridge can be used again if the toner cartridge is refilled with toner. In this way, recycling process cartridges will make effective use of resources.

Japanese Laid-Open Patent Publication No. 2-252910 discloses a new article detecting means for detecting a new article of an image forming unit to be replaced after a predetermined number of times of use, and a number-of-use computing apparatus for computing the number of times of use of the unit. A display means for displaying a replacement request when the number of times of use reaches a predetermined number of times,
When a new unit is detected, the new unit is initialized with the number of times of use calculated by the number-of-uses calculating unit and clearing means for erasing the replacement request displayed by the display unit. A hole, a shield plate slidably provided in the through hole to shield light penetrating the through hole, a moving unit provided on the apparatus main body side for moving the shield plate, and a shield plate in the through hole An image forming apparatus is described which comprises a position sensor for detecting the position.

[0005]

In the above process cartridge, since the components such as the toner cartridge have a life, the toner cartridge and the like are refilled with the toner and recycled for many times, and the operation limit of the process cartridge is exceeded. If used, the components may be damaged. Further, the process cartridge and its surroundings are the parts to which a voltage of several hundreds to several thousands of volts is usually applied from the high voltage power source, and are one of the most dangerous parts in the image forming apparatus. Failure or damage to this part
Risk of danger to the user. An object of the present invention is to provide an image forming apparatus that can be used by a user in a stable and safe state.

[0006]

In order to achieve the above object, the invention according to claim 1 is a cartridge that is exchangeable every predetermined number of times and that is removable from the main body, and whether this cartridge is new or not. New article detection means for detecting
A use number counting means for counting the number of times of use of the cartridge, a recycle number counting means for counting the number of times the cartridge is recycled, and a high voltage power source for applying a high voltage to at least the cartridge by inputting a trigger signal. In the image forming apparatus having the above, the high-voltage power supply is used when the cartridge exceeds the operation limit by judging whether the cartridge exceeds the operation limit based on the count value of the use count counting means and the count value of the recycle count counting means. It is provided with means for masking the trigger signal to the.

According to a second aspect of the present invention, a cartridge which is exchanged every predetermined number of times and which can be attached to and detached from the main body, operating limit detecting means for detecting whether or not the cartridge has exceeded the operating limit, and a trigger signal are provided. In an image forming apparatus having a high voltage power source for applying a high voltage to at least the cartridge by being input, a trigger signal to the high voltage power source is sent when the cartridge exceeds the operating limit by the detection signal of the operating limit detecting means. It is equipped with a masking means.

According to a third aspect of the present invention, a cartridge which is exchanged every predetermined number of times and which can be attached to and detached from the main body, operation limit detecting means for detecting whether or not the cartridge exceeds the operation limit, and power supply from a power source In an image forming apparatus having at least a high-voltage power supply for applying a high voltage to the cartridge, the power supply from the power supply to the high-voltage power supply is shut off when the cartridge exceeds the operation limit according to the detection result of the operation limit detection means. It is equipped with a means to do.

According to a fourth aspect of the present invention, a cartridge which is exchanged at a predetermined number of times and which can be attached to and detached from the main body, operating limit detecting means for detecting whether or not the cartridge has exceeded the operating limit, and a trigger signal are provided. In an image forming apparatus having a high-voltage power supply for applying a high voltage to at least the cartridge by being input, a trigger signal to the high-voltage power supply is sent when the cartridge exceeds the operation limit due to the detection result of the operation limit detection means. It is provided with a means for shutting off.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the invention described in claim 1. This embodiment is an example 11 of an image forming apparatus including a laser printer, and has a main body and a process cartridge 12 that can be attached to and detached from the main body. This laser printer forms an image by a known electrophotographic process, and at the time of image formation, the photosensitive member is rotated by a driving mechanism to be uniformly charged by a charging unit.
The exposure means exposes the photoreceptor with an image signal to form an electrostatic latent image.

The electrostatic latent image is developed by a developing device as a developing means and transferred to a sheet by a transferring means, the toner on the sheet is fixed by a fixing means, and the photosensitive member is fixed by a cleaning unit as a cleaning means. To be cleaned. The developing device is replenished with toner from a toner cartridge, and the process cartridge 12 is a unit in which the toner cartridge, the developing device, the photoconductor, the cleaning unit, and the like are detachably integrated.

The main body has a CPU (microcomputer) 13 as a control means, a use number counter 14, a new article detecting means 15, a recycle number detecting means 16, a high voltage generating section 17, etc., and the process cartridge 12 is shown in FIG.
As shown in FIG. 3, a new article detecting member 18 and a recycling number member 19 are provided. The new-article detection member 18 is set when the process cartridge 12 is a pure new article that has not been recycled at all, is cleared when the process cartridge 12 is used, and is recycled to the main body when the process cartridge 12 is recycled. It will be set again when it is installed.

When the process cartridge 12 is a new product that has not been recycled at all, the recycle count member 1
9 is cleared, and the recycling number member 19 is incremented by +1 every time the toner cartridge is recycled by refilling the toner. The recycle count detecting means 16 detects the value of the recycle count member 19 when the process cartridge 12 is mounted on the main body to detect the recycle count of the process cartridge 12.

The new article detecting means 15 detects whether or not the new article detecting member 18 of the process cartridge 12 attached to the main body is set to determine whether the process cartridge 12 attached to the main article is new. It is also detected whether or not the process cartridge 12 is recycled. The number-of-uses counter 14 counts the number of times the process cartridge 12 is used when the process cartridge 12 is mounted in the main body.

The CPU 13 receives the output signal of the new article detecting means 15 and the output signal of the recycling number detecting means 16,
When the new process cartridge 12 is mounted on the main body, the usage number counter 14 is cleared, that is, the number of recycles of the process cartridge 12 detected by the number-of-recycling detection unit 16 is 0, and the new-unit detection unit 15 sets the process cartridge 12 When it is detected as a new product, the usage counter 14 is cleared.

As shown in FIG. 3, a gate 20 is provided between the CPU 13 and the high voltage generator 17. As shown in FIG. 4, the process cartridge 12 is operable and the mask signal MASK from the CPU 13 is at a low level (L).
, The inverted signal of the high voltage trigger signal (/ high voltage trigger signal) from the CPU 13 is sent to the high voltage generation unit 17 through the gate 20, and the high voltage generation unit 17 operates to apply a high voltage to the process cartridge 12 and a predetermined portion of the main body. Apply.

Here, the count value of the number-of-uses counter 14 is Ks (times), the detection result of the recycling number detecting means 16, that is, the number of times of recycling of the process cartridge 12 is Kr (times), and the process cartridge 12 is recycled once. In this case, if the average number of times the process cartridge 12 is used is n (times), and the number of times the process cartridge 12 is at the operating limit (the limit at which the process cartridge 12 can operate without fear of failure or damage) is Kl (times), then Kl ≦ n × Kt + Ks If the process cartridge 12 is used in the manner (1), the process cartridge 12 may be broken or damaged.

Therefore, as shown in FIG. 5 and FIG.
13 determines whether or not the expression (1) is satisfied (whether Kl> n × Kt + Ks is satisfied) from the count value Ks of the usage number counter 14 and the detection result Kr of the recycle number detection means 16. , Process cartridge 1
If the process cartridge 12 does not exceed the operating limit and the equation (1) is not satisfied, the normal operation is performed to perform the mask signal MA as described above.
By setting SK to L / Gate 2 for high voltage trigger signal
0 to the high voltage generator 17.

Further, when the process cartridge 12 exceeds the operation limit and (1) is established, the CPU 13
The mask signal MASK is set to a high level (H) so that the laser printer 11 and thus the user are not exposed to danger, so that the / high-voltage trigger signal is masked by the gate 20 and an error message is displayed on the display means.
As a result, when the process cartridge 12 exceeds the operating limit, the high voltage generator 17 does not generate high voltage, and there is no danger of danger to the laser printer 11 and the user. In addition, the mask of the high voltage trigger signal is the CPU 13
May be performed only by software processing.

As described above, in the embodiment of the invention described in claim 1, the cartridge 12 which is exchanged every predetermined number of times and which is attachable to and detachable from the main body, and whether or not the cartridge 12 is new is detected. CPU as new product detection means
13, new article detecting means 15 and recycling number detecting means 1
6, a number-of-times counting means 14 for counting the number of times the cartridge 12 has been used, a number-of-recycling member 16 as a number-of-recycling means for counting the number of times the cartridge 12 has been recycled, and at least a cartridge by inputting a trigger signal. In an image forming apparatus having a high voltage generator 17 as a high voltage power source for applying a high voltage to 12, whether the cartridge 12 has exceeded the operating limit based on the count value of the number-of-use counting means 14 and the count value of the number-of-recycling counting means 19. C as a means for masking the trigger signal to the high-voltage power supply 17 when the cartridge 12 exceeds the operating limit as judged.
Since the PU 13 and the gate 20 are provided, when the cartridge is used beyond its operating limit, the high-voltage power supply does not generate a high voltage, and the image forming apparatus and the user are not at risk, and are always stable. It can be used by the user in a safe state.

FIG. 7 shows an embodiment of the invention described in claim 2. This embodiment is an example 21 of an image forming apparatus including a laser printer. In this embodiment example 21,
In the eleventh embodiment of the invention described in claim 1, when the process cartridge 22 exceeds the operation limit and (1) is satisfied, the mask signal MASK is not set to H and an error message is not displayed. The operation limit member 23 provided in the process cartridge 22 as shown in FIG.
On the other hand, when the process cartridge 22 exceeds the operating limit and (1) is satisfied, information indicating that the process cartridge 22 exceeds the operating limit is given and stored.

The process cartridge 22 is the same as the process cartridge 12 except that the operation limit member 2 is used.
3 is provided. The main body is the operation limit detecting means 2
4 is provided, and the operation limit detecting means 24 operates the process cartridge 22 by detecting information from the operation limit member 23 of the process cartridge 22 mounted on the main body when the image forming operation is performed. Detects whether the limit has been exceeded.

As shown in FIG. 9, the CPU 13 determines from the output signal of the operating limit detecting means 24 whether the process cartridge 22 mounted in the main body has exceeded the operating limit, and outputs the output signal of the operating limit detecting means 24. If it is determined that the process cartridge 22 does not exceed the operating limit, the normal operation is performed and the mask signal MAS is set as described above.
By setting K to L / High-voltage trigger signal to gate 20
Through the high pressure generating unit 17.

Further, the CPU 13 uses the operation limit detecting means 2
When it is determined from the output signal of No. 4 that the process cartridge 12 has exceeded the operating limit, the mask signal MA
By setting SK to a high level H, the / high voltage trigger signal is masked by the gate 20 and an error message is displayed on the display means. As a result, when the process cartridge 22 exceeds the operating limit, the high pressure generating unit 17
Does not generate high pressure, and there is no danger of danger to the laser printer 21 and the user. The CPU 13 may mask the high-voltage trigger signal only by software processing.

As described above, in the embodiment of the present invention as set forth in claim 2, the cartridge 22 which is exchanged every predetermined number of times and which can be attached to and detached from the main body, and whether or not the cartridge 22 exceeds the operation limit is detected. Operating limit detection means 24
And an image forming apparatus having a high voltage power supply 17 for applying a high voltage to at least the cartridge 22 by inputting a trigger signal, in the case where the cartridge 22 exceeds the operation limit by the detection signal of the operation limit detecting means 24, the high voltage power supply C as a means for masking the trigger signal to 17
Since the PU 13 and the gate 20 are provided, when the cartridge is used beyond its operating limit, the high-voltage power supply does not generate a high voltage, and the image forming apparatus and the user are not in danger of danger. It can be used by the user in a safe state.

FIG. 10 shows an embodiment of the invention described in claim 3. This embodiment is an example 25 of an image forming apparatus including a laser printer. In the twenty-fifth embodiment, in the twenty-first embodiment of the invention described in claim 2, the CPU 13 does not perform the processing by the output signal of the operation limit detection means 26, and the micro switch is provided between the high voltage generation unit 17 and the power supply 27. The operation limit detecting means 26 consisting of is inserted. The high voltage generator 17 is supplied with power from the power source 27 through the operation limit detecting means 26, and the high voltage trigger signal is sent to the CPU1.
3 is directly input without passing through the gate 20 to generate a high voltage and apply the high voltage to the process cartridge 28 or a predetermined portion of the main body.

As shown in FIG. 11, the process cartridge 28 uses an operation limit member 29 having a projection as an operation limit member in the cartridge 22. The operation limit detecting means 26 is, for example, an operation limit member. A micro switch is used which is operated by being pressed by the protrusions of 29. Here, the protrusion of the operation limit member 29 is like being broken by the rotation of the gear.

Process cartridge 2 mounted on the main body
If 8 does not exceed the operating limit, normal operation is performed. That is, as shown in FIG. 12, the micro switch as the operation limit detecting means 26 is pressed by the protrusion 29 a of the operation limit member 29 to be turned on, and the high voltage generator 17 receives power from the power source 27 through the operation limit detecting means 26. The supplied / high voltage trigger signal is input from the CPU 13 to generate high voltage and apply the high voltage to the process cartridge 28 or a predetermined portion of the main body.

When the process cartridge 28 exceeds the operating limit and the condition (1) is satisfied, the CPU 13 causes the driving means (not shown) to rotate the gear and the operating limit member 2
By bending the projection 29a of No. 9, information indicating that the process cartridge 28 has exceeded the operating limit is given to the operating limit member 29 and stored. After that, when the process cartridge 28 is attached to the main body,
As shown in FIG. 13, the micro switch as the operation limit detecting means 26 is turned off because the operation limit member 29 is no longer pressed by the projection 29a. Therefore, the high voltage generator 17
Is no longer supplied with power from the power source 27 and does not generate high voltage, and there is no danger of danger to the laser printer 25 and the user.

As described above, in the embodiment of the present invention as set forth in claim 3, the cartridge 28 which is exchanged every predetermined number of times and which can be attached to and detached from the main body, and whether or not the cartridge 28 has exceeded the operating limit is detected. An image forming apparatus having a usage number counting means 14, a recycling number counting means 19 and a CPU 13 as operation limit detecting means, and a high voltage generating section 17 as a high voltage power source which is supplied with power from a power source 27 and applies a high voltage to at least a cartridge 28. In the above, the number-of-uses counting means 1 as the operation limit detecting means 1
4. Since the recycling number counting means 19 and the detection result of the CPU 13 provide the operation limit detecting means 26 as means for cutting off the power supply from the power supply 27 to the high voltage power supply 17 when the cartridge 28 exceeds the operation limit, the cartridge is installed. If the user tries to use the battery beyond the operating limit, the high-voltage power supply does not generate high voltage, and there is no danger of danger to the image forming apparatus and the user, and the user can always use the device in a stable and safe state. In addition, the power supply from the power supply to the high-voltage power supply is cut off by hardware, so that a safer configuration is achieved.

FIG. 14 shows an embodiment of the invention described in claim 4. This embodiment is an example 30 of an image forming apparatus including a laser printer. In the thirty-second embodiment, in the twenty-fifth embodiment of the invention described in claim 3, the high voltage generating unit 17 is directly connected to the power source 27 and supplied with power from the power source 27, and // the high voltage trigger signal is supplied. Is inputted from the CPU 13 via the operation limit detecting means 26. As the process cartridge, the above process cartridge 28 is used as shown in FIG.

Process cartridge 2 mounted on the main body
If 8 does not exceed the operating limit, normal operation is performed. That is, as shown in FIG. 16, the microswitch serving as the operating limit detecting means 26 is pressed by the protrusion 29a of the operating limit member 29 to turn on, and the high voltage generating unit 17 sends a high voltage trigger signal from the CPU 13 to the operating limit detecting means 2
A high voltage is generated by being input through a micro switch 6 and applied to the process cartridge 28 and a predetermined portion of the main body.

Further, when the process cartridge 28 exceeds the operation limit and (1) is satisfied, the CPU 13 causes the drive means (not shown) to rotate the gear and the operation limit member 2
By bending the projection 29a of No. 9, information indicating that the process cartridge 28 has exceeded the operating limit is given to the operating limit member 29 and stored. After that, when the process cartridge 28 is attached to the main body,
As shown in FIG. 17, the microswitch as the operation limit detecting means 26 is turned off because the operation limit member 29 is no longer pressed by the projection 29a. Therefore, the high voltage generator 17
Does not generate a high voltage because the high voltage trigger signal is not input from the CPU 13 and there is no danger of danger to the laser printer 25 and the user.

As described above, in the embodiment of the present invention as set forth in claim 4, the cartridge 28 which is exchanged every predetermined number of times and which can be attached to and detached from the main body, and whether or not the cartridge 28 has exceeded the operating limit is detected. An image including the number-of-uses counting unit 14, the number-of-recycling counting unit 19 and the CPU 13 as an operation limit detecting unit, and a high voltage generating unit 17 as a high voltage power source for applying a high voltage to at least the cartridge 28 by inputting a trigger signal. In the forming apparatus, the number-of-uses counting means 14, the number-of-recyclings counting means 19 and C as operation limit detecting means are used.
When the cartridge 28 exceeds the operating limit by the detection result of the PU 13, the operating limit detecting means 26 as means for cutting off the trigger signal to the high-voltage power supply 17 is provided. The high-voltage power supply does not generate high voltage, and there is no danger of danger to the image forming apparatus and the user, and the user can always use the device in a stable and safe state. In addition, the trigger signal to the high-voltage power supply is cut off by hardware, so that a safer configuration is achieved. The present invention is not limited to the above-described embodiment, and can be applied to an image forming apparatus such as a copying machine or a facsimile, and an image forming apparatus in which a cartridge other than the process cartridge is attachable to and detachable from the main body. The operating limit detecting means 26 other than the microswitch can also be used.

[0035]

As described above, according to the first aspect of the present invention, a cartridge which is exchanged every predetermined number of times and which can be attached to and detached from the main body, and a new article detection for detecting whether or not this cartridge is new article Means, use number counting means for counting the number of times of use of the cartridge, recycle number counting means for counting the number of times the cartridge is recycled, and high voltage for applying a high voltage to at least the cartridge by inputting a trigger signal. In an image forming apparatus having a power source, when the cartridge exceeds the operating limit, it is judged whether the cartridge exceeds the operating limit based on the count value of the use number counting means and the count value of the recycle number counting means. A means for masking the trigger signal to the high-voltage power supply, , When attempting to use beyond the operating limits of the cartridge there is no possibility that dangerous to the image forming apparatus and the user high voltage power supply is no longer generates a high pressure, the user can use always a stable and secure state.

According to the second aspect of the present invention, a cartridge that is exchanged every predetermined number of times and that can be attached to and detached from the main body, operation limit detection means for detecting whether or not this cartridge has exceeded the operation limit, and a trigger. In an image forming apparatus having a high voltage power source for applying a high voltage to at least the cartridge when a signal is input, a trigger to the high voltage power source when the cartridge exceeds the operation limit by the detection signal of the operation limit detection unit. Since the signal masking means is provided, the high voltage power supply does not generate high voltage when the cartridge is used beyond the operating limit, and the image forming apparatus and the user are not in danger of danger. It can be used by the user in a safe state.

According to the third aspect of the present invention, a cartridge which is exchanged every predetermined number of times and which can be attached to and detached from the main body, operating limit detecting means for detecting whether or not the cartridge has exceeded the operating limit, and a power source An image forming apparatus having a high-voltage power supply for supplying a high voltage to at least the cartridge by supplying power from the power supply to the high-voltage power supply from the power supply when the cartridge exceeds the operation limit according to the detection result of the operation-limit detection unit. Since a means for shutting off the cartridge is provided, there is no risk that the high-voltage power supply will not generate high voltage and the image forming apparatus and the user will be at risk if the cartridge is to be used beyond its operating limit.
It is always stable and safe for users to use. In addition, the power supply from the power supply to the high-voltage power supply is cut off by hardware, so that a safer configuration is achieved.

According to the invention described in claim 4, a cartridge which is exchanged every predetermined number of times and which can be attached to and detached from the main body, operation limit detecting means for detecting whether or not the cartridge exceeds the operation limit, and a trigger In an image forming apparatus having at least a high voltage power source for applying a high voltage to the cartridge when a signal is input, a trigger to the high voltage power source when the cartridge exceeds the operating limit due to the detection result of the operating limit detecting means. Since a means for shutting off the signal is provided, there is no risk that the high voltage power supply will generate high voltage when the cartridge is used beyond the operating limit, and the image forming apparatus and the user will not be in danger. It can be used by the user in a safe state. In addition, the trigger signal to the high-voltage power supply is cut off by hardware, so that a safer configuration is achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an invention according to claim 1;

FIG. 2 is a schematic view showing a process cartridge of the embodiment.

FIG. 3 is a block diagram showing a part of the embodiment.

FIG. 4 is a timing chart showing an operation timing when the process cartridge is operable in the embodiment.

FIG. 5 is a timing chart showing the operation timing when the process cartridge exceeds the operating limit in the embodiment.

FIG. 6 is a flowchart showing an operation flow of the embodiment example.

FIG. 7 is a block diagram showing an embodiment of an invention according to claim 2;

FIG. 8 is a schematic view showing the process cartridge of the embodiment.

FIG. 9 is a flowchart showing an operation flow of the embodiment.

FIG. 10 is a block diagram showing an embodiment of an invention according to claim 3;

FIG. 11 is a schematic view showing a process cartridge of the embodiment.

FIG. 12 is a block diagram showing a state in which the process cartridge is operable in the embodiment.

FIG. 13 is a block diagram showing a state in which the process cartridge exceeds the operating limit in the embodiment.

FIG. 14 is a block diagram showing an embodiment of an invention according to claim 4;

FIG. 15 is a schematic view showing the process cartridge of the embodiment.

FIG. 16 is a block diagram showing a state in which the process cartridge is operable in the embodiment.

FIG. 17 is a block diagram showing a state in which the process cartridge exceeds the operating limit in the embodiment.

[Explanation of symbols]

 12, 22, 28 Process cartridge 13 CPU 14 Use count counter 15 New article detection means 16 Recycle number detection means 17 High voltage generation section 18 New article detection member 19 Recycle number member 20 Gate 23, 29 Operation limit member 24, 26 Operation limit detection Means 27 Power supply 29a Protrusion

Claims (4)

[Claims] 1. A cartridge which can be attached to and detached from a main body and which is replaced every predetermined number of times of use, a new article detecting means for detecting whether or not this cartridge is new, and a number of times of use counting the number of times of use of the cartridge. Means and
In an image forming apparatus having a recycling number counting means for counting the number of times the cartridge has been recycled, and a high voltage power source for applying a high voltage to at least the cartridge by inputting a trigger signal, a count value of the usage number counting means And a means for masking the trigger signal to the high-voltage power supply when the cartridge exceeds the operating limit from the count value of the recycling number counting means and the cartridge exceeds the operating limit. Image forming apparatus. 2. A cartridge which is exchanged every predetermined number of times of use and which can be attached to and detached from the main body, an operation limit detecting means for detecting whether or not this cartridge has exceeded an operation limit, and at least by inputting a trigger signal. An image forming apparatus having a high-voltage power supply for applying a high voltage to the cartridge, comprising means for masking a trigger signal to the high-voltage power supply when the cartridge exceeds the operation limit by a detection signal of the operation limit detection means. An image forming apparatus characterized by the above. 3. A cartridge which is exchanged every predetermined number of times and which can be attached to and detached from a main body, an operation limit detecting means for detecting whether or not the cartridge exceeds an operation limit, and at least the cartridge which is supplied with power from a power source. An image forming apparatus having a high-voltage power supply for applying a high voltage, comprising means for cutting off power supply from the power supply to the high-voltage power supply when the cartridge exceeds the operation limit by the detection result of the operation limit detection means. An image forming apparatus characterized by. 4. A cartridge which is exchanged every predetermined number of times and which can be attached to and detached from a main body, an operation limit detecting means for detecting whether or not the cartridge has exceeded an operation limit, and at least by inputting a trigger signal. An image forming apparatus having a high-voltage power supply for applying a high voltage to the cartridge, including means for cutting off a trigger signal to the high-voltage power supply when the cartridge exceeds the operation limit according to the detection result of the operation limit detection means. An image forming apparatus characterized by the above.