JPH07113804B2 - Counter reset device for image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to an image forming apparatus such as a copying machine or a laser printer, in which a counter reset is performed when a developer (including toner) cartridge drum or a drum cartridge is replaced. It relates to a reset device.

<Prior Art> Generally, in an image forming apparatus such as a copying machine and a laser printer, an image forming photoreceptor, a developing device, a transfer section, a cleaning section, a charging section, and a fixing section are detachably mounted.
Further, the developing device has a developing tank and a toner replenishing tank.

In recent years, copiers, laser printers, and the like have become user-maintained due to their personalization, and the maintenance is facilitated. The developer cartridge of the developing device can usually make 10,000 to 20,000 copies by using a two-component developer.

However, from the viewpoint of downsizing and space saving with the personalization of copying machines and the like, the toner hopper capacity is limited, and toner cartridges capable of copying several thousand sheets are supplied.

By the way, as for the life of the developer, the number of copies is counted by the control circuit in the main body of the copying machine, and at the same time as the normal life, the indicator is turned on to prompt the replacement of the developer cartridge. Therefore, after the replacement of the developer cartridge, it is necessary to operate the maintenance counter for resetting.

The conventional reset device has the following configuration.

First, as shown in FIG. 9, after replacing the developer cartridge,
The key switches 1, 2, 3, 4, 5, 6 on the operation panel are sequentially operated to perform reset by simulation.

Secondly, the image forming apparatus body is provided with a reset switch,
This is to be pushed by the user during maintenance.

Third, resetting is performed by pushing a mechanical counter or the like.

Fourth, as shown in FIG. 10, when the photoconductor cartridge is replaced, the reset pawl 8 is formed near the front end when the photoconductor cartridge 7 is mounted, and the resetting claw 8 is formed during the mounting operation process (movement operation in the direction of the arrow in the figure). The front surface of the claw 8 pushes the tip of the reset rod 10 of the counter 9, the counter 9 is reset until the photoconductor cartridge 7 is set to a predetermined position, and the photoconductor 7 is further pushed to the regular set position. The claw 8 is pushed and broken by the tip of the reset bar 10 (see Jitsukai Sho 59-176059).

<Problems to be Solved by the Invention> However, in the above-mentioned conventional counter reset device,
There are the following problems.

The first counter reset device compels the user to perform complicated operations. In addition, the service manual must be pulled out when operating. In addition, there is a possibility of mistakenly performing another simulation.
Further, it must be done with the power turned on, and it is necessary to provide a protective measure such as prohibiting copying when the indicator is turned on in case the reset operation is forgotten.

The second counter reset device must be powered on. If the reset switch is attached to the exterior of the main unit, there is a danger that it may be reset by mistake at times other than maintenance and inspection. If it is attached inside the main body, it is difficult to reset and there is a problem such as electric shock.

The third counter reset device is expensive.

According to the fourth counter reset device, the counter is automatically reset by mounting a new cartridge, and the counter is not reset again by this cartridge, which eliminates the above-mentioned first to third drawbacks. it can. However, in this counter reset device, broken pieces of the claws 8 fall into the device, causing troubles such as a failure of the main body of the image forming apparatus.

Therefore, as a counter reset device for eliminating all the above-mentioned drawbacks, there is, for example, the one proposed in Japanese Utility Model Laid-Open No. 62-79251. This is to cut the fuse by supplying a cutable fuse provided in the cartridge with electricity for a certain period of time, and reset the counter on the main body side of the copying machine when the fuse is cut. In this case, since the nail or the like will never be broken, no trouble will be caused by this. However, according to this counter reset device, the old and new cartridges to be mounted are not confirmed and power is supplied, and if the current path is short-circuited for some reason, even the old cartridges will be reset. . That is, if the terminals for energizing are short-circuited due to incorrect mounting of the cartridge (such as when the cartridge is not securely mounted or the cartridge is mounted in the opposite direction), the counter is reset.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a counter reset device of an image forming apparatus which can confirm the old and new of the mounted cartridges and can surely perform the reset operation of the counter.

<Means for Solving Problems> The means for solving problems according to the present invention is, as shown in FIGS. 1 to 8, an image forming cartridge 12 on an image forming apparatus main body 11.
In a detachably mounted image forming apparatus, a light emitting element 13 arranged in the cartridge 12 and a light receiving element 14 arranged at a position facing the light emitting element 13 when the cartridge 12 is mounted, and the cartridge 12 A power supply circuit 15 for supplying power to the light emitting element 13 from the image forming apparatus body 11 side separately from the power source in the image forming apparatus body 11 when the
A counter 18 for counting the number of copies and the like, and a control circuit 19 for resetting the counter 18 by an output signal of the light receiving element 14 by receiving light from the light emitting element 13, the control circuit 19 being provided. When the power source of the image forming apparatus main body 11 is switched from the off state to the on state or when the door of the image forming apparatus main body 11 is switched from the open state to the closed state, the operation detecting means 20 that outputs an on signal, and the on signal Output determining means 21 for determining whether or not the light emitting element 13 emits light based on the output of the light receiving element 14, and reset means for resetting the counter 18 when the light emission of the light emitting element 13 is determined by the output determining means 21. 22 and a light emitting element destruction means 23 for outputting a destruction signal to the power supply circuit 15 so as to supply an overcurrent that destroys the light emitting element 13 in connection with the mounting of the cartridge 12 Is.

<Operation> In the means for solving the above problems, when the cartridge 12 is replaced, a new cartridge 12 is attached to the image forming apparatus main body 11 and the power switch is turned on, or when the door switch of the image forming apparatus main body 11 is turned on, the power supply circuit is turned on. Energization of the light emitting element 13 by 15 is started. Due to this energization, the light emitting element 13 emits light, the light is received by the light receiving element 14, the light receiving signal (H signal) of the light receiving element 14 is input to the output determining means 21 of the control circuit 19, and the output determining means 21 It is determined that the light emitting element 13 emits light. In other words, a new cartridge 12
Is confirmed to have been installed.

Therefore, when the new cartridge 12 is attached, the light emitting element 13 emits light, and this light emission is confirmed via the light receiving element 14. As a result, a signal instructing to reset the counter 18 is output from the reset means 22 to the counter 18, and the contents of the counter 18 are reset.

On the other hand, in connection with the mounting of the cartridge 12, the light emitting element destruction means 23 supplies an overcurrent to the light emitting element 13 via the power supply circuit 15, and the light emitting element 13 is destroyed.

Here, when the non-new cartridge 12 is mounted and the power switch is turned on, even if the light emitting element 13 is energized for some reason, the light emitting element 13 has already been destroyed, so no light reception signal is confirmed. , I will not reset the counter unless it is a new cartridge 12.

<Embodiment> An embodiment in which the counter reset device of the image forming apparatus according to the present invention is applied to a developing device will be described below with reference to the 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 flow chart thereof, and FIG. 3 is an electric circuit diagram of a signal generating element and a light receiving element. FIG. 5 is a rear view of the developing device showing a 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 is directed to an image forming apparatus in which a developing device cartridge 12 is detachably attached to an image forming apparatus main body 11 and a signal generating element 13 disposed in the cartridge 12 is provided.
A signal receiving element 14 arranged at a position facing the signal generator 13 in the image forming apparatus main body 11, and a power supply circuit 15 for supplying power to the signal generating element 13 from the image forming apparatus main body 11 side. , The image forming apparatus main body interposed in the power supply circuit 15
An energizing connector 16, 17 for electrically connecting the 11 side and the cartridge 12 side, a counter 18 for counting the number of copies, etc.,
A control circuit 19 for resetting the counter 18 according to the output signal of the light receiving element 14 is provided.

The control circuit 19 determines the output of the light receiving element 14 by the operation detecting means 20 for detecting the power-on or the door opening / closing state of the image forming apparatus main body 11 for detecting the ON state of the door stitch, and the ON signal of the operation detecting means 20. Output determining means 21, a resetting means 22 for resetting the counter 18 by a light receiving signal of the output determining means 21, and an overcurrent for destroying the signal generating element 13 after the output determination of the output determining means 21 is supplied. The power supply circuit 15 is provided with a signal generating element destruction means 23 for outputting a destruction signal.

The image forming apparatus main body 11 is detachably mounted with an image forming photoreceptor, a developing device, a transfer section, a cleaning section, a charging section, and a fixing section.

The cartridge 12 is for a developing device, and as shown in FIG. 5, a developing tank 28 containing a developing roller 26 and a stirring roller 27, and a toner replenishing tank for supplying toner to the developing tank 28.
29, and a developer supply chamber 30 in which a developer (toner and carrier) is housed in the developer tank 28. The fifth
In the figure, 31 is a toner replenishing roller, 32 is a seal material, and when used, the winding shaft 33 is rotated to peel off the seal material 32 and supply the developer from the developer supply chamber 30 to the developing tank 28.

The signal generating element 13 is, for example, a photodiode and is fixed to the back side of the developing device as shown in FIG. In FIG. 4, reference numerals 35 and 36 are a developing roller, a stirring roller drive gear, and 37 is a winding shaft drive gear.

The light receiving element 14 is a phototransistor
As shown in the figure, the image forming apparatus main body is opposed to the signal generating element 13.
It is fixed to the 11 side and the power source 38 (5V) is supplied as shown in FIG.

As shown in FIG. 4, the energizing connectors 16 and 17 are arranged on the back side of the developing device and on the side of the image forming apparatus main body 11 opposite thereto. A parallel connection body of a large resistance R1 (470 ohms), a small resistance R2 (10 ohms) and a relay contact 39 is interposed in the power supply circuit 15 and is connected to a power supply 40 (24V).

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

The control circuit 19 is a general one-chip microcomputer, which has a CPU, a ROM, and a RAM. A terminal for inputting a signal from the light receiving element 14 is input to its input portion, and a counter 18 is reset to its output portion. It has a terminal for outputting an instruction signal and a terminal for outputting a drive signal to a drive circuit (not shown, which is composed of a switching element and a relay coil) of the relay contact 39.

Next, the resetting method of the cartridge 12 will be described with reference to FIGS. When a new developing device is attached to the image forming apparatus main body 11 when the developing device is replaced, the energizing connectors 16, 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 circuit 15 is connected, current flows through the signal generating element 13, and the signal generating element 13 emits light. To do. The emitted light is received by the light receiving element 14, and the received light signal (H signal) is input to the output determination means 21 of the control circuit 19. The output determination means 21 determines whether or not the signal generating element 13 emits light.

As a result of the determination, when the signal generating element 13 emits light (in the case of H signal), it is determined to be a new developing device, and the counter 18
The reset means 22 outputs a signal instructing the reset to the counter 18.

At the same time, a signal for turning on the relay contact 39 of the power supply circuit 15 is output. When the relay contact 39 turns on, the power circuit
In the case of 15, the power source flows through the small resistance R2 side, so an overcurrent (a current of 2 to 100 times the normal current) flows and the signal generating element 13 (photodiode) is destroyed.

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

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

Further, since the reset signal is transmitted only once when the power is turned on when the cartridge is replaced and the door is closed, the cartridge may be replaced not when the power is turned on. In addition, there is no burden on the user such as pressing the reset switch or performing a simulation.

Further, since the phototransistor is used as the light receiving element, noise does not occur on the signal line to the CPU of the control circuit.

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

FIG. 6 is a control flow chart 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 a mounting state of the signal generating element and the light receiving element. It is an electric circuit diagram which shows.

As shown in FIG. 8, the counter reset device of the image forming apparatus according to the present invention uses a photo interrupter 50 in which the signal generating element 13 of the first embodiment and the light receiving element 14 are integrated. , On the substrate 51 on the rear side of the developing device,
The photo interrupter 50 is installed.

The energizing connectors 16 and 17 and the signal line are connected to the image forming apparatus main body 11 side via the energizing connectors 16 and 17.

Further, the control circuit 19 is controlled so that an overcurrent (500 mA) larger than a normal current (for example, 50 mA) flows when the power is turned on or the door is closed.

The other structure is similar to that of the first embodiment.

Next, the control operation will be described with reference to FIG.

When the power is turned on or the door switch is turned on after the developing device is replaced, the control circuit 19 causes an overcurrent to flow in the power circuit 15 and an excessive current in the signal generating element 13 of the photo interrupter 50.

Then, for a moment, the signal generating element 13 (photodiode) is turned on, the light receiving element 14 (phototransistor) is activated, and the counter 18 of the CPU is reset.

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

Therefore, the same effect as the first embodiment can be expected.

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, in the above embodiment, the count reset at the time of replacement of the developing device has been described, but the present invention is also applicable to the counter reset at the time of replacement of cartridges such as a photoconductor, a cleaning device, and a charging device, which are necessary for image formation. Of course, it can be applied.

<Effects of the Invention> As is apparent from the above description, according to the present invention, after the new cartridge is mounted on the image forming apparatus main body, the power is turned on or the door opening / closing switch of the image forming apparatus main body is turned on so that the cartridge side is turned on. The light emitting element emits light, and this light is received by the light receiving element to confirm that a new cartridge has been installed and reset the contents of the counter. Prevents accidental resetting of the counter when a new cartridge cartridge is installed, or when a non-new cartridge cartridge is installed and the current path including the light emitting element is short-circuited for some reason. Therefore, the counter can be reset surely.

Further, it is not necessary to perform a simulation for resetting the counter or a manual resetting operation, and when the burden on the user is eliminated, an excellent effect can be obtained.

[Brief description 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 flow chart thereof, and FIG. 3 is an electric circuit diagram of a signal generating element and a light receiving element. FIG. 5 is a rear view of the developing device showing a mounting state of a signal generating element and a light receiving element, FIG. 5 is a sectional view of the developing device, and FIG. 6 is a control flow chart 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, FIG. 8 is an electric circuit diagram showing a mounting state of the signal generating element and the light receiving element, and FIG. 9 is a reset shimray of a conventional counter reset device. FIG. 10 is a front view showing the relationship between a photoconductor 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 detecting means, 2
1: output determination means, 22: reset means, 23: signal generating element destruction means.

Claims (1)

[Claims] 1. An image forming apparatus in which an image forming cartridge is detachably attached to an image forming apparatus main body, and the light emitting element is disposed on the cartridge and is disposed at a position facing the light emitting element when the cartridge is attached. Light receiving element, a power supply circuit that supplies power to the light emitting element from the image forming apparatus main body side when the cartridge is attached, a counter that counts the number of copies, and the light emitting element. And a control circuit for resetting the counter in response to an output signal of the light receiving element due to reception of light from the image forming apparatus, the control circuit is provided when a power source in the image forming apparatus main body is switched from an off state to an on state or an image. Operation detecting means for outputting an ON signal when the door of the forming apparatus main body is switched from open to closed, and the operation detecting means is turned on. Output determining means for determining whether or not the light emitting element emits light from the output of the light receiving element, and resetting means for resetting the counter when the light emission of the light emitting element is determined by the output determining means, A counter reset device for an image forming apparatus, comprising: a light emitting element destruction means for outputting a destruction signal to the power supply circuit so as to supply an overcurrent that destroys the light emitting element in connection with mounting of a cartridge. .