JPH0981015A - Process cartridge and electrophotographic image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of sensors, to reduce the number of assembling processes and that of inspection processes of the sensor and to attain the cost reduction by detecting the remaining quantity of the toner and the loading state of a process cartridge by one detecting means. SOLUTION: In the case the output voltage value of a magnetic bridge sensor 25 is equal to or exceeding a specified value, it shows such the state that the process cartridge C is normally loaded, and also, the toner required for forming an image remains in the cartridge, then, the device is controlled so as to form the image. The presence or absence of the remaining quantity of toner in the process cartridge C and the loading/unloading state of the process cartridge C are detected by one sensor 25 in such a way, and in the case the toner does not remain, or, in the case the process cartridge C is not loaded, an alarm is displayed, and also, forming the image is stopped. Thus, it is unnecessary to individually install a sensor for detecting the presence or absence of the remaining quantity of toner and a sensor for detecting the loading of the cartridge.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process cartridge used in an electrophotographic recording system and an electrophotographic image forming apparatus for forming an image using the process cartridge.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic image forming process, an electrophotographic photosensitive member and a developing means having a developing roller for developing a latent image formed on the electrophotographic photosensitive member are provided. A process cartridge system is adopted in which the cartridge is integrally formed and the cartridge can be attached to and detached from the main body of the image forming apparatus. According to this process cartridge system, the maintenance of the apparatus can be performed by the user himself without relying on a service person, so that the operability can be remarkably improved. Therefore, this process cartridge system is widely used in image forming apparatuses.

Many of the image forming apparatuses as described above have a toner remaining amount detecting means for detecting the presence or absence of a developer (hereinafter referred to as "toner") or the remaining amount.
As the method of detecting the remaining toner amount, various methods such as an optical method using a light emitting element and a light receiving element, an electrostatic capacity method for detecting the electrostatic capacity of the toner, a piezoelectric method for detecting the toner pressure by vibration, and the like are available. A scheme has been proposed.

The amount of remaining toner is detected by the above-mentioned method, and when the amount of toner falls below a certain amount, replenishment of toner or replacement of the process cartridge is urged, or the image forming operation is stopped to prevent image fading or omission. There is.

Further, in the image forming apparatus in which the process cartridge is mounted, in order to detect the mounting of the process cartridge so that the image forming operation is not performed in the state where the process cartridge is not mounted, a photo sensor or A sensor such as a micro switch is provided.

[0006]

SUMMARY OF THE INVENTION The present invention is a further development of the above process cartridge and image forming apparatus. The object of the present invention is to find the number of parts for toner remaining amount detection and process cartridge mounting detection. The present invention provides a process cartridge and an electrophotographic image forming apparatus capable of reducing the cost by reducing the assembly process and the detection process.

Another object of the present invention is to provide an electrophotographic image forming apparatus capable of suppressing the probability of erroneous detection of the remaining toner amount and the mounting state of the process cartridge.

[0008]

A typical structure of the present invention for achieving the above object is to provide an electrophotographic image forming apparatus for forming an image on a recording medium in which a process cartridge can be attached and detached. And a mounting means for removably mounting a process cartridge having a developing means for developing the latent image formed on the electrophotographic photosensitive member, and a residual toner amount in the toner storage portion of the process cartridge. The present invention is characterized in that detection means and detection means for detecting the attachment / detachment state of the process cartridge and conveyance means for conveying the recording medium are provided.

In the above structure, the detection of the remaining amount of toner and the mounting state of the process cartridge are performed by one detecting means, so that the number of sensors can be reduced, and the assembly process and the inspection process of the sensor can be reduced to reduce the cost. Can be planned.

Further, by using a magnetic permeability sensor as the detecting means, the probability of erroneous detection can be suppressed.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, as a preferred embodiment of the present invention, a first embodiment will be described first, and then another embodiment will be described.

[First Embodiment] A first embodiment will be described with reference to FIGS. 1 to 8. In the first embodiment, the electrophotographic image forming apparatus according to the present invention is applied to a facsimile machine. FIG. 1 is an explanatory view of the entire configuration of the facsimile machine, FIG. 2 is an external view of the facsimile machine, and FIG. 4 is an explanatory view of the structure of the process cartridge, FIG. 4 is an external view of the process cartridge, FIG. 5 is an explanatory view of the mounting structure of the process cartridge, and FIGS. 6 to 9 are explanatory views of the remaining toner amount and the process cartridge mounting detection structure.

Here, the order of the description is as follows: the overall structure of the facsimile device, the structure of a reading device for reading document information, the structure of an image forming device for recording a received image, and the process cartridge used for the image forming device. Of the process cartridge, the structure for mounting the process cartridge, and the structure of the toner remaining amount and the process cartridge mounting detecting means.

{Overall Configuration of Facsimile Apparatus} This facsimile apparatus has a document reading apparatus A in the upper left and an electrophotographic image forming apparatus B in the lower right as shown in FIG. Then, the information read by the reader A is
In the facsimile mode, the image is transmitted to another facsimile machine, and in the copy mode, its own image forming apparatus B
To record.

As shown in FIG. 1, the electrophotographic image forming apparatus B irradiates a laser beam from the optical means 1 on the basis of image information to form a toner image on a photoconductor drum 7 which is an electrophotographic photoconductor. . Then, the recording medium 2 is conveyed by the recording medium conveying means 3 in synchronization with the formation of the toner image,
In addition, the toner image formed on the photoconductor drum 7 in the image forming portion formed as the process cartridge C is transferred onto the recording medium 2 by the transfer means 4, and the recording medium 2 is conveyed to the fixing means 5 to transfer the toner image. Is fixed and the sheet is discharged onto either the face-down tray 6a or the face-up tray 6b.

Further, a magnetic bridge sensor 25, which is a detecting means for detecting the presence or absence of toner in the toner chamber 10a so as to contact the developing wall member 12b of the process cartridge C, and for detecting the mounting of the cartridge. It is provided on the device body side.

{Reading Device} The reading device A is for reading the information described in the original document by conveying the original document 13 by the original document conveying means 14. The structure is as shown in FIG.
And the document 13 stacked on the auxiliary table 14b is separated by the separation roller 14
Separated one by one by a separating piece 14d pressed against c, the original 13 is conveyed by a pair of conveying rollers 14e, and the original 13 is conveyed by a pressing means 14f.
Is read against the contact type sensor of the reading means 15 while closely contacting the information, and then the document 13 is discharged to the outside of the reading device A by a pair of discharge rollers 14g.

The reading means 15 includes an LED 15 as a light source.
The information recording surface of the manuscript 13 is irradiated with light from a, and the reflected light is imaged on the photoelectric conversion element 15c through the short-focus imaging lens 15b to read the information. In the facsimile mode, the image is transmitted to another device, and in the copy mode, it is transmitted to the image forming apparatus B of its own.

Incidentally, as shown in FIG.
In a, a direction perpendicular to the conveying direction of the document 13 (width direction of the document 13)
A slidable slider 14h is provided on the original document. By sliding the slider 14h in accordance with the width of the original document 13, both sides of the original document 13 loaded on the original document table 14a can be aligned.

{Image Forming Apparatus} Next, the configuration of each part of the image forming apparatus B which forms an image in response to a recording signal will be described.

The optical means 1 irradiates a light image on the photoconductor drum 7 by irradiating light on the basis of image information read from the reading device A or a facsimile device of another machine, and as shown in FIG. A laser diode 1b, a polygon mirror 1c, a scanner motor 1d, an imaging lens 1e, and a reflection mirror 1f are housed in the optical unit 1a.

Then, for example, when an image signal is given from a facsimile machine of another machine, the laser diode 1b emits light according to the image signal and illuminates the polygon mirror 1c as image light. The polygon mirror 1c is rotated at a high speed by a scanner motor 1d, and the image light reflected by the polygon mirror 1c is radiated to the rotating photosensitive drum 7 via the imaging lens 1e and the reflection mirror 1f, and the surface of the drum 7 is covered. It is selectively exposed to form a latent image according to image information.

Next, the recording medium conveying means 3 for conveying the recording medium 2 is arranged below the image forming apparatus B,
The uppermost one of the recording mediums 2 loaded in the feeding cassette 3a that can be pulled out from one end of the feeding unit D is a pickup roller 3b provided on the upper end of the leading end of the recording medium 2.
Then, the sheet is separated and fed one by one by the separation pad 3c pressed against the sheet, and is fed to the pair of conveying rollers 3e while making a U-turn along the conveying guide 3d. The recording medium 2 is conveyed to the image transfer portion so that the conveying roller pair 3e is synchronized with the image forming operation. Then, the recording medium 2 after the image transfer
Is conveyed to the fixing means 5 by the guide member 3f, and the recording medium 2 after fixing is discharged to the face-down tray 6a by the discharge roller pairs 3g and 3h when face-down discharge, and discharged by switching the switching guide 3j when face-up discharge. The sheet is discharged onto the face-up tray 6b by the roller pair 3g.

The transfer means 4 is an image forming portion in the photosensitive drum 7.
The toner image formed on the recording medium 2 is transferred onto the recording medium 2. The transfer means 4 of this embodiment is composed of a transfer roller 4 as shown in FIG. That is, the recording medium 2 conveyed to the photosensitive drum 7 of the mounted process cartridge C is pressed by the transfer roller 4, and the transfer roller 4 is pressed.
The toner on the photosensitive drum 7 is transferred to the recording medium 2 by applying a voltage having a polarity opposite to that of the toner image formed on the photosensitive drum 7 to a.

The fixing means 5 is for fixing the toner image transferred to the recording medium 2 by applying a voltage to the transfer roller 4. As shown in FIG. 1, the structure is composed of a driving roller 5a that is driven to rotate, and a fixing member 5c that has a heater 5b inside and a sheet member that is driven to rotate by being pressed against the driving roller 5a. When the recording medium 2 to which the toner image has been transferred in the image forming section passes between the driving roller 5a and the fixing member 5c, pressure is applied by pressing the both 5a and 5c and heat is generated by the heater 5b. Is applied to fix the toner on the recording medium 2 to the recording medium 2.

As described later, such an image forming apparatus is provided with mounting means for the process cartridge C,
The process cartridge C is mounted by the mounting means to form an image.

{Process Cartridge} Next, the structure of each part of the process cartridge C will be described. As shown in FIG. 3, in the process cartridge C, a photosensitive drum 7 having a photosensitive layer as an electrophotographic photosensitive member rotates in the direction of the arrow, and a voltage is applied to a charging roller 8 serving as a charging means on the surface of the photosensitive drum 7. The photosensitive drum 7 is charged with a light and is exposed to the photosensitive drum 7 through the exposure opening 9a to form a latent image, and the latent image is developed by the developing means 10.

The developing means 10 supplies the toner in the toner chamber 10a, which is a toner storage portion, to the developing chamber 10b, rotates the developing roller 10c attached to the developing chamber 10b, and imparts a triboelectric charge by the developing blade 10d. The toner layer is formed on the surface of the developing roller 10c containing a fixed magnet, and the toner is transferred to the photosensitive drum 7 according to the latent image to form a toner image and visualize it.

Then, after a voltage having a polarity opposite to that of the toner image is applied to the transfer roller 4 to transfer the toner image to the recording medium 2, the cleaning blade 11a scrapes off the toner remaining on the photosensitive drum 7 and discards it. Toner storage section 11b
The residual toner on the photosensitive drum 7 is removed by the cleaning means 11 which collects the toner.

Incidentally, the respective parts such as the photosensitive drum 7 are housed and supported in a cartridge frame body constituted by connecting the toner developing frame body 12a, the developing wall member 12b, and further the cleaning frame body 12c to form a cartridge. Has been done. That is, the toner developing frame 12a and the developing wall member 12b are welded to each other to fuse the toner chamber 10
a and a developing chamber 10b are formed, the toner chamber 10a is filled with magnetic toner, and the developing roller 10c and the developing blade 10d are attached to the developing chamber 10b. Further, the photosensitive drum 7, the charging roller 8, and each member constituting the cleaning means 11 are attached to the cleaning frame 12c.
Then, the cleaning frame 12 is attached to the toner developing frame 12a.
A process cartridge C is constructed by coupling c. Incidentally, the toner developing frame 12a in the present embodiment,
The developing wall member 12b and the click frame 12c are made of plastic, and are made of plastic such as polystyrene, ABS resin (acrylonitrile / butadiene / styrene copolymer), polycarbonate, polyethylene, polypropylene or the like.

An exposure opening 9a for image exposure is provided on the upper part of the process cartridge C, and a transfer opening 9b for bringing the photosensitive drum 7 into contact with the recording medium 2 is provided on the lower part. is there. Further, a shutter member 16 capable of opening and closing both openings 9a and 9b is attached. This shutter member 16 is, as shown in FIG. 3, a cleaning frame 12c.
Is attached so as to be rotatable around a shaft 16a, and is constantly biased in a closing direction by a torsion coil spring 17 (see FIG. 4) attached to the shaft 16a, and the process cartridge C is attached to the image forming apparatus B. Then, the locking portion 16b provided on the shutter arm is locked at a predetermined position of the apparatus main body to open the shutter member 16.

{Mounting of Process Cartridge} Next, the structure of the mounting means for detachably mounting the process cartridge C in the image forming apparatus B will be described.

As shown in FIG. 4, the process cartridge C has a circular first protrusion 18 as a positioning means on both side surfaces (both ends in the axial direction of the photosensitive drum 7) of the cleaning frame 12c in the longitudinal direction, and a posture. A circular second protrusion 19 for holding is provided (FIG. 4 shows only one side). The first protrusion 18
Is a cleaning frame 12c which is coaxial with the axis of the photosensitive drum 7.
It is provided so as to project to the outside. The second protrusion 19 is also provided so as to project to the outside of the cleaning frame 12c,
Further, it is behind the first protrusion 18 in the insertion direction when the process cartridge C is inserted into the image forming apparatus B,
Also, with the photosensitive drum 7 positioned below, the first protrusion
It is provided above 18. Further, in the present embodiment, the handle portion 12c1 is integrally provided on the upper surface of the cleaning frame 12c, and the operator holds and operates the handle portion 12c1 when attaching or detaching the process cartridge C. Incidentally, the handle part
As shown in FIG. 5, 12c1 is the first protrusion 18 and the second protrusion.
It is provided so as to be located above a line E-E connecting the centers of 19.

On the other hand, in the image forming apparatus B, as shown in FIG. 1, the apparatus main body is covered with an outer cover 20, and the outer cover 20 is provided with an opening / closing cover 20b which is an opening / closing member rotatable by a shaft 20a. It is attached. And the cover 20
When b is opened, a cartridge mounting space is provided inside the main body of the apparatus, and guide members 21 as cartridge mounting means as shown in FIG. 5 are mounted on both left and right sides of the space. The guide member 21 is provided with a guide groove 21a for guiding the first protrusion 18 and the second protrusion 19 of the process cartridge C in a diagonally downward direction, and a positioning recess 21b is formed at the end of the guide groove 21a. I am doing it.

Therefore, when the process cartridge C is mounted on the apparatus main body, the operator opens the opening / closing cover 20b,
As shown in FIG. 5, the first protrusion of the process cartridge C
18 and the second protrusion 19 along the guide groove 21a, the cartridge C is inserted into the apparatus, and the first protrusion 18 is positioned in the positioning recess.
Position the cartridge by dropping it into 21b. In the mounted state of the process cartridge C, the second protrusion 19 is locked in the guide groove 21a, and the posture of the process cartridge C is maintained.

Further, in this embodiment, the guide member 21
As shown in FIG. 5, the torsion coil spring is biased clockwise around the shaft 22a and locked to the locking portion 22b.
22 is attached. Therefore, process cartridge C
When the first protrusion 18 falls into the positioning recess 21b, the first protrusion 18 pushes up the spring 22. Therefore, the first protrusion 18
Is biased obliquely downward by the urging force of the spring 22 to be pressed against the positioning recess 21b, and is reliably positioned and fixed in the positioning recess 21b. As a result, the process cartridge C is reliably positioned and mounted in the apparatus main body in a stable state.

A drum gear 23, which is a helical gear and is a driving force receiving portion for receiving a driving force from the apparatus main body, is fixed to one end of the photosensitive drum 7 in the longitudinal direction.
Therefore, when the process cartridge C is mounted in the image forming apparatus B as described above, the drum gear 23 is provided in the apparatus main body and meshes with the drive gear 24 which is a helical gear for driving force transmission connected to the motor. The rotational force is transmitted to the photosensitive drum 7 by receiving the driving force from the main body of the apparatus.

Next, when the process cartridge C is to be removed from the main assembly of the apparatus, the first projection 18 fits into the positioning recess 21b even if the process cartridge C is to be pulled out as it is.
It cannot be pulled out. Therefore, it is necessary to remove the fitting state of the first projection 18 and the positioning recess 21b and then to pull out. In the present embodiment, the release of the fitted state can be performed in association with the pulling-out operation. As a result, in the present embodiment, when the process cartridge C is taken out, the engagement between the drum gear 23 and the drive gear 24 is smoothly released.

That is, when the process cartridge C is taken out, if the operator pulls the handle portion 12c1 toward the front, the process cartridge C rotates counterclockwise in FIG. The fitting state of the first protrusion 18 and the positioning recess 21b is easily released. At the same time, the engagement between the drum gear 23 and the drive gear 24 is smoothly released. This will be specifically described with reference to FIG.
As shown in FIG. 4, when the handle portion 12c1 is pulled in the direction of the arrow P, the y component Py of the force P of the first projection 18 with the second projection 19 as a fulcrum.
As a rotation moment, the first protrusion 18 easily comes out of the positioning recess 21b. Then, the x-component Px of the force P causes the first protrusion 18 and the second protrusion 19 to move into the guide groove 21.
By sliding along a, the process cartridge C is pulled out. Therefore, the operator can easily take out the process cartridge C from the image forming apparatus B simply by pulling the handle portion 12c1 in the direction of arrow P (the direction of taking out the cartridge C).

{Detection Unit for Toner Remaining Amount and Process Cartridge Mounting} Next, the structure of the detection unit for detecting the remaining amount of toner stored in the toner chamber 10a of the process cartridge C and the presence or absence of the process cartridge mounting will be described. .

In this embodiment, the remaining amount of toner and the presence / absence of mounting of the process cartridge are determined by one sensor 25. This sensor 25 is a magnetic bridge sensor which is a magnetic permeability sensor, and as shown in FIG. 6, a detection head 25a is mounted on the sensor body in a cylindrical shape. The signal line 25b is connected to exchange signals with the main body of the apparatus.

As shown in FIG. 3, when the process cartridge C is mounted on the sensor 25, the sensor head 25a is brought into contact with the wall portion of the toner chamber 10a in the developing wall member 12b of the cartridge C. , Attached to the device body.

A detection transformer (not shown) is embedded in the detection head 25a. This detection transformer is composed of one primary winding and two secondary windings consisting of a reference winding and a detection winding. It consists of three windings. The detection winding is located on the top surface side of the detection head 25a (the surface contacting the developing wall member 12b), and the reference winding is located on the back side of the detection head 25a with the primary winding interposed therebetween.

When a current having a signal of a constant waveform is input to the primary winding from the oscillator provided in the sensor body, electromagnetic induction is also applied to the two secondary windings including the reference winding and the detection winding. As a result, a current having a signal of a predetermined waveform flows. At this time, a signal having a constant waveform from the oscillator and a signal having the above-mentioned waveform of the current flowing from the detection winding due to electromagnetic induction are compared and judged by a comparison circuit (not shown) provided in the sensor main body to detect the detection head 25a. The density of the magnetic substance (toner) on the top surface side of is detected. That is, different output voltages can be obtained with and without the magnetic substance in front of the detection head 25a.
It is possible to magnetically detect the remaining amount of toner in 10a.

In the sensor 25, a ferrite screw core is movably provided at the center of the detection transformer in order to cope with the difference in magnetic density of the magnetic substance to be detected. It is possible to detect and adjust by adjusting, and it is possible to properly detect the magnetic substance.

In order to detect the toner with high accuracy by the sensor 25, as shown in FIG. 3, the developing wall member 12b of the process cartridge C, which is the wall portion of the toner chamber 10a with which the sensor 25 contacts. A concave portion 12b1 for magnetically detecting the remaining amount of toner is formed in the portion, and the thickness of the portion is made thinner than the other portions. As a result, when the process cartridge C is mounted, the portion of the detection head 25a comes closer to the toner contained in the toner chamber 10a, and the accuracy of detecting the remaining amount of toner is increased.

The operation of detecting the remaining amount of toner by the sensor 25 will now be described more specifically. The concave portion 12b1 with which the sensor 25 abuts is sufficiently filled with toner in the toner chamber 10a, as indicated by Tf in FIG. While the toner is a magnetic substance, the detection head 25a faces the developing wall member 12b through the developing wall member 12b, and when the toner in the toner chamber 10a becomes almost empty as shown by Te in FIG. Is provided near the bottom of the toner chamber 10a where toner T does not exist at a position facing the detection head 25a.

The sensor 25 outputs a high voltage when the magnetic toner is present at the position facing the detection head 25a, and the output voltage is low when the toner is not present at the position facing the detection head 25a. Therefore, as shown in FIG. 7, a high voltage is output while the toner remaining amount is the maximum filling (the position of Tf) and the toner necessary for image formation exists, and the toner remaining amount is the mounting position of the magnetic bridge sensor 25. The output voltage decreases when it is near, and the lowest voltage is output when the remaining amount of toner is almost empty (the position of Te). As a result, the output of the sensor 25 can detect the remaining amount of toner in the toner chamber 10a and can output a signal indicating that the state is not suitable for image formation immediately before the toner is exhausted.

Further, when the process cartridge C is removed from the main body of the apparatus, since there is no magnetic substance near the sensor 25, the analog output signal of the sensor 25 has the lowest output as in the case where the toner is empty. Indicates the voltage. Therefore, it is possible to output a signal not suitable for image formation, as in the case of no toner.

Based on the signal detected by the sensor 25, the control means performs a predetermined display and controls the image forming operation. FIG. 8 is a block diagram showing the configuration of the control means, and 26 is a control unit for controlling the entire apparatus, for example, a CPU such as a microprocessor, a ROM for storing the control program of the CPU and various data, The RAM is used as a work area of the CPU, and includes a RAM for temporarily storing various data.

Further, the control unit 26 inputs a signal from the magnetic bridge sensor 25 to display a predetermined display on the display unit 27 provided on the upper part of the main body of the apparatus, and at the same time, the reading apparatus A, the optical means 1, the charging means. 8, the driving of the developing unit 10, the transfer unit 4, the fixing unit 5, the recording medium conveying unit 3, etc. is controlled.

The control procedure of the remaining toner amount detection and the process cartridge mounting detection by the control unit 26 is performed as shown in the flowchart of FIG. When the power of the apparatus main body is turned on, the initialization operation of the apparatus is performed in step S1. Next, in step S2, the output voltage of the magnetic bridge sensor 25 is detected, and when the value is below a certain value, the toner in the process cartridge C is empty or the process cartridge C is mounted in the apparatus main body. Since it is not in the state, the flow advances to step S3 to display on the display unit 27 a message prompting the user to inspect the cartridge, and the flow advances to step S4 to stop the image forming operation of the apparatus. At this time, if the image is received, the image forming operation is not performed, but the process proceeds to step S5 and the image data is stored in the memory provided in the control unit 26 by the proxy reception. As a result, it is possible to prevent the recorded image from fading or missing due to the absence of toner, and to prevent the device from being driven when the process cartridge C is not mounted.

On the other hand, in step S2, the sensor
If the output voltage value of 25 is a certain value or more, it means that the process cartridge C is normally mounted and the toner in the cartridge remains in an amount necessary for image formation. Therefore, the process proceeds to steps S6 and S7. Control to perform image formation with.

In this way, with one sensor 25,
It is possible to detect whether the process cartridge C has a toner remaining amount and whether the process cartridge C is mounted,
And when there is no toner remaining or the process cartridge C
If is not attached, a warning is displayed and the image forming operation can be stopped. Therefore, it is not necessary to separately provide a sensor for detecting the remaining amount of toner and a cartridge mounting detection sensor, the number of sensors and the assembly process thereof can be reduced, and the cost can be reduced.

Further, in the present embodiment, as described above, the sensor 25 and its sensor are used to detect the presence / absence of the remaining amount of toner and the presence / absence of the mounting of the process cartridge C by using the magnetic permeability sensor. If the detection circuit is normal, there is no erroneous detection, the operation inspection of the sensor is easy, and the probability of erroneous detection can be suppressed. That is, the defect rate can be suppressed only by the operation confirmation inspection process of the sensor 25, the inspection process is simplified, and the cost can be reduced also in this respect. Further, the recessed portion 12b1 of the process cartridge C in which the sensor 25 is located can accurately detect the remaining amount of toner or the like regardless of whether it is transparent or opaque.

[Other Embodiments] Next, other examples of each part of the process cartridge and the image forming apparatus according to the above-described embodiment will be described.

Although the above-mentioned process cartridge is for forming a monochromatic image, the process cartridge is not limited to the case of forming a monochromatic image, but a plurality of developing means are provided and a multicolor image (for example, a two-color image is formed). It can also be suitably applied to a cartridge that forms a three-color image or full-color image.

As the developing method, various known developing methods such as a two-component magnetic brush developing method, a cascade developing method, a touchdown developing method and a cloud developing method can be used.

The electrophotographic photosensitive member is not limited to the above-mentioned photosensitive drum, but includes, for example, the following. First, a photoconductor is used as the photoconductor, and examples of the photoconductor include amorphous silicon, amorphous selenium, zinc oxide, titanium oxide, and an organic photoconductor (OP).
C) and the like. The shape on which the photoconductor is mounted includes, for example, a rotating body such as a drum or a belt, and a sheet. In general, a drum-shaped or belt-shaped one is used. For example, in the case of a drum-type photoconductor, a photoconductor is deposited or coated on a cylinder of an aluminum alloy or the like. It is.

As for the structure of the charging means, the so-called contact charging method was used in the above-described first embodiment, but a tungsten wire conventionally used as another structure is provided with metal shields such as aluminum around the three sides, It goes without saying that a configuration may be used in which positive or negative ions generated by applying a high voltage to the tungsten wire are moved to the surface of the photosensitive drum to uniformly charge the surface of the drum.

The charging means may be of a blade type (charging blade), a pad type, a block type, a rod type, a wire type or the like, other than the roller type.

Further, as a method for cleaning the toner remaining on the photosensitive drum, the cleaning means may be constituted by using a blade, a fur brush, a magnetic brush or the like.

The process cartridge according to the present invention comprises at least an electrophotographic photosensitive member and developing means. Therefore, as a typical mode thereof, the developing means, the electrophotographic photosensitive member, the charging means and the cleaning means are integrally made into a cartridge which can be attached to and detached from the apparatus main body. Further, the developing means, the electrophotographic photosensitive member, and the charging means or the cleaning means are integrally formed into a cartridge,
It can be attached to and detached from the device body. Further, there is one in which the developing means and the electrophotographic photosensitive member are integrally made into a cartridge, which can be attached to and detached from the apparatus main body.

Further, in the above-described embodiment, in order to detect the magnetic toner with high accuracy by the magnetic permeability sensor, the toner accommodating portion of the process cartridge is provided with a thin walled concave portion, and the magnetic permeability sensor is positioned in the concave portion. However, if the magnetic permeability sensor has a good sensitivity to the wall thickness of the wall of the toner storage portion in the process cartridge, the recess may not be provided on the wall of the toner storage portion. It is possible to detect the toner remaining amount and the cartridge mounting state by the individual sensors.

Further, although the laser beam printer has been illustrated as the image forming apparatus in the above-described embodiment, the present invention is not limited to this, and other examples such as an LED printer, an electrophotographic copying machine, a facsimile machine, or a word processor can be used. Of course, it can be used in an image forming apparatus.

[0066]

As described above, the present invention reduces the number of sensors and the number of sensor assembling steps and inspection steps by detecting the remaining toner amount and the mounting state of the process cartridge by one detecting means. The cost can be reduced.

By using a magnetic permeability sensor as the detecting means, the probability of false detection can be suppressed.

Further, if a recess is provided on the wall surface of the process cartridge in which the sensor is located, the detection accuracy can be improved.

[Brief description of drawings]

FIG. 1 is an overall configuration explanatory diagram of a facsimile apparatus to which a process cartridge according to an embodiment of the present invention and an image forming apparatus are applied.

FIG. 2 is an explanatory view illustrating the appearance of a facsimile apparatus.

FIG. 3 is a configuration explanatory view of a process cartridge.

FIG. 4 is an external view of a process cartridge.

FIG. 5 is a diagram illustrating a mounting configuration of a process cartridge.

FIG. 6 is an external view of a magnetic bridge sensor.

FIG. 7 is an explanatory diagram showing the output of the magnetic bridge sensor with respect to the amount of toner in the toner chamber.

FIG. 8 is a block diagram of a control system.

FIG. 9 is a flowchart showing an operation procedure of toner remaining amount detection and cartridge mounting detection.

[Explanation of symbols]

1 ... Optical means, 2 ... Recording medium, 3 ... Recording medium conveying means,
4 ... Transfer means, 5 ... Fixing means, 6a, 6b ... Tray, 7
... Photosensitive drum, 8 ... Charging rollers, 9a, 9b ... Opening portion, 10 ... Developing means, 10a ... Toner chamber, 10b ... Developing chamber, 10
c ... developing roller, 10d ... developing blade, 11 ... cleaning means, 12a ... toner developing frame, 12b ... developing wall member, 12
b1 ... Recess, 12c ... Cleaning frame, 12c1 ... Handle, 13
... manuscript, manuscript conveying means, 15 ... reading means, 16 ... shutter member, 16a ... shaft, 16b ... locking part, 17 ... coil spring, 18 ... first projection, 19 ... second projection, 20 ... exterior cover, 20a ... Axis, 20
b ... Open / close cover, 21 ... Guide member, 21a ... Guide groove, 21
b ... concave part, 22 ... coil spring, 22a ... shaft, 22b ... locking part,
23 ... Drum gear, 24 ... Drive gear, 25 ... Magnetic bridge sensor, 25a ... Detection head, 25b ... Signal line, 26 ... Control section, 27
... Display

Claims (8)

[Claims] 1. A process cartridge attachable to and detachable from a main body of an electrophotographic image forming apparatus, an electrophotographic photosensitive member, a developing unit for developing a latent image formed on the electrophotographic photosensitive member, and the electrophotographic photosensitive member. And a cartridge frame body for supporting the developing means, and a recess for magnetically detecting the remaining toner amount in a part of the cartridge frame body forming the wall surface of the developer accommodating portion in the developing means. A process cartridge characterized by being provided. 2. The process cartridge is a cartridge in which the developing means, the electrophotographic photosensitive member, the charging means, and the cleaning means are integrally formed as a cartridge and can be attached to and detached from the main body of the image forming apparatus. Item 1. The process cartridge according to Item 1. 3. The process cartridge is a cartridge in which the developing unit, the electrophotographic photosensitive member, and a charging unit or a cleaning unit are integrally made into a cartridge and can be attached to and detached from the main body of the image forming apparatus. Item 1. The process cartridge according to Item 1. 4. The process cartridge according to claim 1, wherein the developing means and the electrophotographic photosensitive member are integrally made into a cartridge so as to be attachable to and detachable from the image forming apparatus main body. 5. An electrophotographic image forming apparatus for forming an image on a recording medium, wherein a process cartridge is attachable / detachable, for developing an electrophotographic photosensitive member and a latent image formed on the electrophotographic photosensitive member. Mounting means for detachably mounting a process cartridge having a developing means, detection for detecting the remaining amount of the developer in the developer storage portion of the process cartridge, and detection for detecting the mounting / dismounting state of the process cartridge An electrophotographic image forming apparatus comprising: a unit and a conveying unit configured to convey the recording medium. 6. An electrophotographic image forming apparatus for forming an image on a recording medium, wherein a process cartridge is attachable / detachable, for developing an electrophotographic photosensitive member and a latent image formed on the electrophotographic photosensitive member. A developing device and a cartridge frame for supporting the electrophotographic photosensitive member and the developing device are provided, and the remaining toner amount is provided in a part of the cartridge frame forming the wall surface of the developer accommodating portion in the developing device. A mounting means for removably mounting a process cartridge provided with a magnetically detecting recess, a detection of the remaining amount of the developer in the developer storage portion of the process cartridge, and a mounting / dismounting state of the process cartridge. A detection means for performing detection, and a conveyance means for conveying the recording medium, wherein the detection means is the electrophotographic image forming apparatus main body. Electrophotographic image forming apparatus is characterized by providing so as to be positioned in the concave portion of the process cartridge mounted. 7. The electrophotographic image forming apparatus according to claim 5, wherein the detection unit is a magnetic permeability sensor. 8. The electrophotographic image forming apparatus according to claim 5, wherein the image forming apparatus is an electrophotographic copying machine, a laser beam printer, or a facsimile machine.