JPH02120754A - Counter reset device for image forming device - Google Patents

Abstract

PURPOSE:To prevent the counter from being reset erroneously by constituting the device so that when a power source switch is turned on after replacing a cartridge, a photodetecting signal is inputted to a control circuit and resets the counter, and simultaneously, breaks down a signal generating element. CONSTITUTION:When a cartridge 12 is installed in a body 11 and a power source switch is turned on, a current flows to a signal generating element 13 from a power source circuit 15 and the element 13 emits a light beam. This emitted light is photodetected by a photodetector 14, and whether it is an H signal or not is decided by an output deciding means 21 of a control circuit 19. At the time of an H signal, a counter 18 of the number of copy pieces is reset by a reset means 22, and simultaneously, an excess current is allowed to flow and the signal generating element 13 is broken down by a signal generating element breakdown means 23. Accordingly, thereafter, even if the power source is turned on and off, and the door is opened and closed, the element 13 is not generated, and it does not occur that the counter is reset erroneously.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a counter reset method for resetting a counter when replacing a developer (including toner) cartridge or a drum cartridge in an image forming apparatus such as a copying machine or a laser printer. It is related to the device.

2. Description of the Related Art Image forming apparatuses such as copying machines and laser printers are generally equipped with a photoreceptor for image forming, a developing device, a transfer section, a cleaning section, a charging section, and a fixing section removably attached.

Further, the developing device includes a developer tank and a toner supply tank.

In recent years, as copying machines, laser printers, etc. become more personalized, efforts have been made to facilitate user maintenance. The developer cartridge of the developing device can normally make 10,000 to 20,000 copies if a two-component developer is used.

However, as copying machines become more personalized, they are becoming smaller, and from the perspective of space saving, the toner hopper capacity is limited, and toner cartridges that can make several dozen copies are used.

By the way, the lifespan of the developer is determined by counting the number of copies made by a control circuit within the main body of the copying machine, and normally, at the same time as the lifespan is reached, an indicator is lit to prompt replacement of the developer cartridge. Therefore, after replacing the developer cartridge, it is necessary to perform an operation to reset the maintenance counter.

Conventional reset devices include those having the following configuration.

First, as shown in Figure 9, after replacing the developer cartridge,
Key switch group 1, 2.3°4.5.6 on the operation panel
The reset is performed by sequentially repeating and simulating the steps.

Second, a reset switch is provided on the main body of the image forming apparatus,
This button is pressed by the user during maintenance.

Thirdly, a mechanical counter or the like is pressed to reset it.

Fourthly, as shown in FIG. 10, in replacing the photoconductor cartridge 17, a reset melon 8 is formed near the front end when the photoconductor cartridge 7 is installed, and during the installation operation process (movement in the direction of the arrow in the figure). operation), the front of this gourd 8 pushes the tip of the reset rod 10 of the counter 9, and by the time the photoreceptor cartridge 7 is set in a predetermined position, the counter 9 is reset, and the photoreceptor 7 is further moved to the normal setting position. When pushed in, the gourd 8 is pushed and broken by the tip of the reset rod 10 (see Utility Model Publication No. 59-176059).

Problems to be Solved by the Invention However, the conventional counter reset device described above has the following problems.

The first counter reset device forces the user to perform complicated operations. Furthermore, during operation, it is necessary to pull out the service manual each time, and there is a possibility that another simulation may be performed by mistake.

Furthermore, it is troublesome as it must be done with the power turned on, and it is necessary to take protective measures such as prohibiting copying when the indicator lights up in case the reset operation is forgotten.

Regarding the second counter reset device, it is necessary to perform it while the power is on. If the reset switch is attached to the exterior of the main unit, there is a risk that it will be reset by mistake at times other than maintenance and inspection. If it is attached inside the main unit, it will be difficult to reset and there is a risk of electric shock.

The third counter reset device is costly.

In the fourth counter reset device, pieces of the broken melon 8 may fall into the mounting, causing problems such as failure of the main body of the image forming apparatus.

In view of the above, the present invention provides a counter reset function for an image forming apparatus that allows the cartridge to be replaced at times other than when the power is turned on, and eliminates the burden on the user such as pressing a reset switch or having the user perform a simulation. The purpose is to provide equipment.

Means for Solving the Problems> The means for solving the problems according to the present invention is an image forming apparatus in which an image forming cartridge 12 is removably attached to an image forming apparatus main body 11, as shown in FIGS. 1 to 8. In this case, power is supplied to the signal generating element 13 disposed in the cartridge 12, the signal light receiving element 14 disposed at a position facing the signal generating element 13, and the signal generating element 13 from the image forming apparatus main body 11 side. A power supply circuit 15 for supplying power, a counter 18 for counting the number of copies, etc., and a control circuit 19 for resetting the counter 18 based on the output signal of the light receiving element 14 are provided. an operation detection means 20 for detecting the ON state of the door opening/closing switch of the image forming apparatus main body 11; an output determination means 21 for determining the output of the light receiving element 14 based on the ON signal of the operation detection means 20; and the output determination means Resetting means 2 for resetting the counter 18 by the light reception signal of 21;
2, signal generating element destroying means 23 for supplying an overcurrent that destroys the signal generating element 13 after determining the output of the output determining means 21 and outputting a destructive signal to the power supply circuit 15;
This is what we are made to have.

<Operation> In the above problem solving means, when replacing the cartridge 12, the new cartridge 12 is inserted into the image forming apparatus main body 11.
When the power switch is turned on or the door switch of the image forming apparatus main body 11 is turned on, the power supply circuit 1
5 is connected, current flows through the signal generating element 13, and the signal generating element 13 emits light. The emitted light is received by the light receiving element 14, and a light receiving signal (H signal) is input to the output determining means 21 of the control circuit 19. The output determining means 21 determines whether the signal generating element 13 emits light.

As a result of the determination, if the signal generating element 13 emits light (H
signal), it is determined that the developing device is new, and a signal instructing to reset the counter 18 is sent to the reset means 2.
2 and is output to the counter 18.

At the same time, an overcurrent flows through the power supply circuit 15 by the signal generating element destroying means 23, and the signal generating element 13 is destroyed.

If the result of the determination is a cull signal, the developing device is not new, so no signal for resetting the counter 18 is output.

Therefore, even if the door is opened or the power is turned on or off thereafter, the signal generating element 13 will not emit light and will not be erroneously reset.

Further, since the reset signal is applied only once when the power is turned on when replacing the cartridge and when the door is closed, the cartridge does not have to be replaced when the power is turned on.

In addition, there is no burden on the user such as pressing the reset F switch or having the user perform a simulation. (Embodiment) Hereinafter, an embodiment in which the counter reset device of an image forming apparatus according to the present invention is applied to a developing device will be described. The explanation will be based on the drawings.

FIG. 1 is a control function block diagram of a counter reset device showing the first embodiment of the present invention, FIG. 2 is the same control flowchart, and FIG. FIG. 4 is a rear view of the developing device showing the mounting state of the signal generating element and the light receiving element, and FIG. 5 is a sectional view of the developing device.

As shown in the drawings, the present invention provides an image forming apparatus in which a developing device cartridge (12) is detachably attached to an image forming apparatus main body 11. A signal light receiving element 1 disposed at a position facing the signal generating element 13 in the device main body 11
4, and the image forming apparatus main body 1 is connected to the signal generating element 13.
A power supply circuit 15' that supplies power from the power supply direction 15, and a current-carrying connector 16, 17 that is interposed in the power supply direction 15 and electrically connects the image forming apparatus main body 11 side and the cartridge 12 side.
A counter 18 for counting the number of copies, etc., and a control circuit 19 for resetting the counter 18 based on the output signal of the light receiving element 14 are provided.

The control circuit 19 controls whether the power is turned on or the image forming apparatus main body 11
an operation detection means 20' that detects the on state of a door switch that detects the opening and closing of the door; an output determination means 21 that determines the output of the light receiving element 14 based on the ON signal of the operation detection means 20; and the output determination means a reset means 22 for resetting the counter 18 in response to a received light signal of 21;
A signal generation element destruction means 23 is provided for outputting a destruction signal to the power supply circuit 15 so as to supply an overcurrent that destroys the power supply circuit 15.

The image forming apparatus main body 11 has a photoreceptor for image forming, a developing device, a transfer section, a cleaning section, a charging section, and a fixing section removably attached thereto.

The cartridge 12 is for a developing device,
As shown in FIG. 5, there is a developer tank 28 containing a developing row 226 and an agitating row 227, a toner supply tank 29 that supplies toner to the developer tank 28, and a developer (toner and carrier) installed in the developer tank 28. A developer supply chamber 30 is formed. In addition, in FIG. 5, 31 is a toner supply roller, 32
is a sealing material, and when in use, the sealing material 32 is peeled off by rotating the winding shaft 33, and the developer is supplied from the developer supply chamber 30 to the developer tank 28.

The signal generating element 13 is, for example, a photodiode, and is fixed to the rear side of the developing device as shown in FIG.

In FIG. 4, 35 and 36 are developing roller and stirring roller drive gears, and 37 is a winding shaft drive gear.

The light-receiving element 14 is a phototransistor, and as shown in FIG.
) is supplied.

As shown in FIG. 4, the electrical connectors 16 and 17 are connected to the rear side of the developing device and the image forming apparatus main body 1 opposite thereto.
It is placed on the 1st side. The power supply circuit 15 includes a large resistance R
1 (470 ohms), a small resistance R2 (10 ohms) and a relay contact 39 are interposed in parallel, and a power source 40 (
24V).

The counter 18 counts the number of copies, etc., and is arranged on an operation panel or the like on the top surface of the image forming apparatus main body 11, and is controlled by a control circuit 19.

The control circuit 19 is a one-chip microcomputer with a CPU, ROM, and RAM, and has a terminal for inputting a signal from the light receiving element 14 at its input section, and a terminal for resetting the counter 18 at its output section. and a terminal for outputting a drive signal to a drive circuit (not shown, but consisting of a switching element and a relay fill) of the relay contact 39.

Next, we will explain how to reset the cartridge 12 in Section 1.2.3.
This will be explained based on the diagram. When a new developing device is attached to the image forming apparatus main body 11 at the time of replacing the developing device, the current-carrying connectors 16 and 17 are connected.

Then, when the power switch is turned on or the opening/closing door of the image forming apparatus main body 11 is closed and the door switch is turned on, the power supply circuit 15 is connected and current flows through the signal generating element 13. Emits light. The emitted light is received by the light receiving element 14, and a light receiving signal (H signal) is input to the output determining means 21 of the control circuit 19. The output determining means 21 determines whether the signal generating element 13 emits light.

As a result of the determination, if the signal generating element 13 emits light (H
signal), it is determined that the developing device is new, and a signal instructing to reset the counter 18 is sent to the reset means 2.
2 is output to the counter 18.

At the same time, a signal that turns on the relay contact 39 of the power supply circuit 15 is output. When the relay contact 39 is turned on, the power flows through the small resistor R2 in the power supply circuit 15, so an overcurrent (about 2 times to 100 times the normal current) flows.
The signal generating element 13 (photodiode) is destroyed.

If the result of the determination is an L signal, the developing device is not new, so the signal for resetting the counter 18 is not output.

Therefore, even if the door is opened or the power is turned on or off thereafter, the signal generating element 13 will not emit light and will not be erroneously reset.

In addition, since the only reset signal is sent only when the power is turned on when replacing the cartridge and when the door is closed, it is not necessary to replace the cartridge when the power is turned on6.Also, ask students to press the reset switch or perform a simulation. (There is no burden on the user such as).

Further, since a 7-bit transistor is used as a light receiving element, noise is not introduced to the signal line to the CPU of the control circuit.

Next, a second embodiment of the present invention will be described.

@Figure 6 is a control flowchart of a counter reset device showing a second embodiment of the present invention, Figure 7 is an electric circuit diagram of the signal generating element and light receiving element, and Figure 8 shows the mounting state of the signal generating element and light receiving element. FIG.

As shown in the figure, the counter reset device for an image forming apparatus according to the present invention uses a photointerrupter 50 that integrates the signal generating element 13 and the light receiving element 14 of the first embodiment, as shown in FIG. , the substrate 5 on the back side of the developing device
1, a photo interrupter 50 is mounted.

These current-carrying connectors 16.17 and signal lines are connected to the image forming apparatus main body 1 via the current-carrying connectors 16.17.
Connected to side 1.

In addition, the control circuit 19 generates an overcurrent (50n+A) larger than the normal current (for example, 50n+A) when the power is turned on or the door is closed.
00mA) is controlled to flow.

The other configurations are the same as those of the first embodiment.

Next, the control operation will be explained based on FIG.

After replacing the developing device, when the power is turned on or the door switch is turned on, the control circuit 19 causes an overcurrent to flow through the power supply circuit 15.
An excessive current is passed through the signal generating element 13 of the photointerrupter.

Then, at a -moment, the signal generating element 13 (7 otodiodes) lights up, the light receiving element 14 (7 ototransistors) operates, and the counter 18 of the CPU is reset.

After that, the signal generating element 13 (photodiode) is destroyed, so the second reset signal is not generated.

Therefore, the same effects as in the first embodiment can be expected.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

For example, the signal generating element 13 is not limited to the 7-otodiode as in the above embodiment, but may also be a fuse lamp or the like.Also, in the above embodiment, the counter reset when replacing the developing device was explained, but other Of course, the present invention can also be applied to counter reset when replacing cartridges such as photoreceptors, cleaning devices, and charging devices necessary for image formation.

<Effects of the Invention> As is clear from the above description, according to the present invention, after replacing the cartridge, when the power switch is turned on or the door switch of the image forming apparatus main body is turned on, the signal generating element and the light receiving element are activated. The signal is input to the control circuit, and at the same time the counter is reset, the signal generating element destruction means causes an overcurrent to flow and destroy the signal generating element, so that the signal will not be generated even if the door is opened or the power is turned on or off. The element will not emit light and will not be reset by mistake.In addition, when the power is turned on when replacing the cartridge, as in the past,
Since the only reset signal is applied only when the door is closed, the cartridge does not have to be replaced when the power is turned on.

In addition, there is an excellent effect that there is no burden on the user such as pressing a reset switch or having to perform a simulation as in the past.

[Brief explanation of drawings]

FIG. 1 is a control function block diagram of a counter reset device showing a first embodiment of the present invention, FIG. 2 is a control flowchart thereof, FIG. 3 is an electric circuit diagram of a signal generating element and a light receiving element, and FIG. 4 5 is a sectional view of the developing device, and FIG. 6 is a control flowchart of a counter reset device showing a second embodiment of the present invention. FIG. 7 is an electric circuit diagram of the signal generating element and the light receiving element, and FIG. 8 is an electric circuit diagram showing the installation state of the signal generating element and the light receiving element.
FIG. 9 is a diagram showing a reset simulation of a conventional counter reset device, and FIG. 10 is a front view showing the relationship between a photoreceptor and a counter reset device in another conventional example. 11: Image forming apparatus main body, 12: Cartridge, 13:
Signal generating element, 14: Signal light receiving element, 15: Power supply circuit,
16.17: Energizing connector, 18: Counter, 19: Control circuit, 20: Operation detection means, 21: Output determination means, 2
2: Resetting means, 23: Signal generating element destruction means. Applicant Sharp Corporation

Claims (1)

[Claims] In an image forming apparatus in which an image forming cartridge is detachably attached to an image forming apparatus main body, a signal generating element disposed on the cartridge, a signal light receiving element disposed at a position facing the signal generating element, a power supply circuit that supplies power to the signal generating element from the image forming apparatus main body side;
A counter that counts the number of copies, etc., and a control circuit that resets the counter using an output signal from the light receiving element are provided. an output determination means for determining the output of the light-receiving element based on an ON signal of the operation detection means; a reset means for resetting the counter based on a light reception signal of the output determination means; and an output determination means. A counter reset device for an image forming apparatus, further comprising signal generating element destroying means for outputting a destroying signal to the power supply circuit so as to supply an overcurrent that destroys the signal generating element after determining the output of the signal generating element.