JP2003295595A - Developing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device capable of informing an operator that there is possibility that a specified-quality image can not be formed in a state where the residual amount of developer is found, and an image forming apparatus. <P>SOLUTION: The developing device 2 having a rotating developer carrier 21 and a developer storing part 24 is provided with at least the parts 28 and 29 of a developer residual amount detection mechanism for detecting the residual amount of the developer in the storing part 24 and a counter means 3 for counting the number of revolutions of the carrier 21. <P>COPYRIGHT: (C)2004,JPO

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 using an electrophotographic system, an electrostatic recording system, etc., and a developing device used in this image forming apparatus.
In particular, it can be suitably applied to an image forming apparatus capable of forming a color image.

[0002]

2. Description of the Related Art Conventionally, for example, in an electrophotographic image forming apparatus, an electrophotographic photosensitive member (hereinafter simply referred to as "photosensitive member"), which is generally a rotating drum type as an image bearing member, is used as a charging means. The surface of the charged photoconductor is imagewise exposed by an image exposure means to form an electrostatic latent image corresponding to the exposed image, and the toner of the developer is developed by the developing means on the electrostatic latent image. Are attached to develop a toner image, and the toner image is transferred to a recording material. The toner image transferred onto the recording material is fixed by the fixing means, and then the recording material is discharged as a recorded image (copy, print) out of the apparatus.

In such an image forming apparatus, the developing means and the developer accommodating portion are integrally formed into a cartridge (development cartridge) which can be attached to and detached from the main body of the apparatus, or a photosensitive member and a photosensitive member. The cartridge attaching / detaching method is widely adopted in which at least one of a charging unit, a developing unit, and a cleaning unit as a process unit that acts on the device is integrally formed into a cartridge to form a process cartridge that can be attached / detached to / from the apparatus main body. .

Conventionally, the developers used in the developing means are roughly classified into a one-component developer mainly composed of resin toner particles and a two-component developer mainly composed of resin toner particles and magnetic carrier particles. .

The one-component developing system is superior to the two-component developing system in the following points, and is particularly suitable for the cartridge system in which the user replaces the developing device. (1) Since only the toner is mainly used as the developer, a means for stirring the magnetic particles and the toner is unnecessary. (2) A mechanism for keeping the mixing ratio of the magnetic particles and the toner constant is unnecessary. (3) When a non-magnetic toner suitable for forming a color image is used, a magnet is not required inside the developer carrying body for supplying the developer to the image carrying body.

From the above, it is possible to provide a simple, small-sized and low-cost device.

FIGS. 10A and 10B schematically show a cross section of a conventional one-component developing device using a one-component developer. Next, with reference to FIGS. 10A and 10B, a conventional one-component developing device will be described.

The developing device 2A shown in FIG. 10 (a) is a developing system in which the developing roller 21 as a developer carrying member and the drum type photosensitive member as an image carrying member, that is, the photosensitive drum 1 are not in contact with each other. It is suitable. The toner in the toner hopper 24, which is the developer accommodating portion, is sent from the toner hopper 24 to the developing chamber 25 by the stirring member 26 rotating in the direction of the arrow in the drawing. The toner sent to the developing chamber 25 is configured by providing a sponge layer such as urethane sponge on a core metal, and is configured by a coating roller 22 that rotates in the arrow direction in the figure, and is configured by a rigid body such as aluminum, SUS, or resin. It is supplied onto the developing roller 21 which rotates in the direction of the arrow in the figure.

The toner supplied onto the developing roller 21 is
Thin layer coating by a developing blade 23 as a developer layer thickness regulating member configured by providing a rubber or elastomer such as urethane rubber or silicon rubber on a support plate as an elasticity imparting member composed of phosphor bronze or SUS To be done. The developing roller 21 and the photosensitive drum 1 are held in a gap of 50 μm to 500 μm by a space member (not shown).
Further, at least at the time of development, a predetermined bias is applied to the developing roller 21 from a bias power source (not shown), the toner applied to the developing roller 21 is supplied to the photosensitive drum 1, and the toner formed on the photosensitive drum 1 is discharged. The latent image is developed into a visible image (toner image).

The developing device 2B shown in FIG. 10 (b) is suitable for a developing system in which the developing roller 21 as a developer bearing member and the photosensitive drum 1 as an image bearing member are in contact with each other. Figure 10
The difference from the non-contact type developing device 2A of (a) is that the developing roller 21 is an elastic roller made of rubber such as urethane rubber, silicon rubber, and NBR.
Is the point of contact with the photosensitive drum 1. Further, the developing blade 23 may be a blade in which rubber or elastomer is provided on the elastic supporting plate, but as shown in FIG. 10B, an elastic metal plate such as phosphor bronze or SUS is bent into an L-shape. Alternatively, the bent portion may be brought into contact with the developing roller 21.

In each of the developing devices shown in FIGS. 10A and 10B, the toner hopper 24 is provided with optically transparent transparent members 27a and 27b. The transparent members 27a and 27b receive the irradiation light of the light emitting element 28 provided in the main body of the image forming apparatus by the light receiving element 29 also provided in the main body of the image forming apparatus.
It is provided to detect the remaining amount of toner in the toner cartridge 4.
That is, the irradiation light from the light emitting element 28 is irradiated in the direction of the arrow in the figure, but when the toner is sufficiently in the toner hopper 24, the toner blocks the irradiation light and is not received by the light receiving element 29. When the toner in the toner hopper 24 becomes low, the irradiation light is not blocked by the toner and is received by the light receiving element 29. The remaining toner amount detection method of the optical detection method is a method widely used today because it has a simple structure and can reliably detect the remaining toner amount.

[0012]

However, the conventional developing device has the following problems. That is, if an original document with an extremely low print ratio is continuously printed, the reproducibility of the highlight part will deteriorate and the granularity of the entire image will increase even if the toner in the toner hopper is sufficient. This may have caused deterioration of quality.

Although the one-component developing device has the above-mentioned advantages, when the toner is not consumed in the low print image, the toner not consumed is applied by the coating roller 22 and the developing blade 2.
Repeatedly rubbed at 3. The above problem is prominent particularly in the one-component developing device because the charging characteristics of the toner are deteriorated due to such repeated rubbing.

In particular, in a color image forming apparatus, an original document having a very low printing rate may be printed, for example, only a company / company name logo, a part of ruled lines, or only characters to be emphasized. Usually, toner consumption is 4% to 4% by using A4 or letter size recording material as a standard developer usage state.
It is designed assuming that an image is formed at an image printing rate of 5%, but in the case of the above-described image original, there are many cases where it is 1% or less.

On the other hand, in a color image forming apparatus, image data such as a photograph is also used as an original, and in this case, the required image quality is higher than that of a normal character original, and the above-mentioned deterioration of image quality becomes more serious. There is a risk. In this case, the user needs to replace the developing device with a new one and print again.

However, if the life of the developing device is defined only by the number of rotations of the developing roller 21, an image having a high image coverage of 10 to 20% is printed, contrary to the case of the low coverage image. In this case, before the number of rotations of the developing roller 21 reaches the number of rotations judged to be the end of life, the developer in the developing device is exhausted, and the original function of notifying the replacement time of the developing device does not work.

Therefore, it is an object of the present invention to provide a developing device and an image forming apparatus capable of notifying an operator that an image of a predetermined quality may not be formed in the state where there is a remaining amount of the developer. Is to provide.

[0018]

The above object is achieved by the developing device and the image forming apparatus according to the present invention. In summary, the first aspect of the present invention is, in a developing device having a rotating developer carrier and a developer accommodating portion, a developer residual amount detection for detecting the residual amount of the developer in the developer accommodating portion. A developing device comprising at least a part of a mechanism and a counter means for counting the number of rotations of the developer carrying member.

According to the second aspect of the present invention, in the image forming apparatus having the developing device including the rotating developer carrier and the developer accommodating portion, the remaining amount of the developer in the developer accommodating portion is detected. A developer remaining amount detecting mechanism, a counter means for counting the number of rotations of the developer carrying member, the developer remaining amount detecting mechanism detects that the developer remains, and the counter means An image forming apparatus is provided, which comprises: a control unit that generates a signal for indicating that when the number of rotations of the developer carrier reaches a predetermined number of rotations.

According to each of the embodiments of the present invention, the predetermined rotation speed is a rotation speed of the developer carrying member which is 2 to 10 times as high as that when the standard developer is used.

In each of the above inventions, according to one embodiment, the counter means rotates with the rotation of the developer carrying member, and the rotation of the developer carrying member via the gear train. And a display member capable of transmitting rotation speed information of the developer carrier, the image forming apparatus further detecting the rotation speed information of the developer carrier transmitted by the display member. Have. The display member is
The display state detected by the detection member may change when the number of rotations of the developer carrier reaches the predetermined number of rotations. According to each of the other embodiments of the present invention described above, the counter means is an electrical or magnetic storage means, and the image forming apparatus further stores the rotation speed of the developer carrier in the storage means. And means for writing magnetically or magnetically.

The image forming apparatus may further include display means, and can display information according to the signal generated by the control means. The image forming apparatus may further include means for transmitting the signal generated by the control means to an external device communicatively connected to the main body of the image forming apparatus.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION A developing device and an image forming apparatus according to the present invention will be described below in more detail with reference to the drawings.

Embodiment 1 FIG. 1 shows a schematic configuration of an embodiment of an image forming apparatus according to the present invention. In the present embodiment, the present invention is a recording material using an electrophotographic method according to an image information signal from an external host device such as a personal computer communicatively connected to an image forming apparatus main body (apparatus main body). , For example,
It is embodied in a laser beam printer that forms an image on a recording sheet, an OHP sheet, cloth, or the like.

The image forming apparatus 100, as an image carrier,
The photosensitive drum 1 is formed by applying an organic photoconductor (OPC) or a photoconductor such as A-Si (amorphous silicon), CdS, or Se to the outer peripheral surface of an aluminum cylinder. The photosensitive drum 1 is rotationally driven in the direction of the arrow in the figure by a driving unit (not shown), and its surface is uniformly charged by a charging roller 6 as a charging unit. Next, the charged photosensitive drum 1 is scanned and exposed by a laser beam L according to an image information signal by an exposure device (laser scanner) 7 as an image exposure means, and an electrostatic latent image is formed on the surface thereof.
When the photosensitive drum 1 is further rotated, the electrostatic latent image formed on the photosensitive drum 1 is visualized as a toner image by the developing device 2 supplying toner as a developer. In this embodiment, a one-component developer (toner) mainly composed of resin toner particles is used as the developer.

On the other hand, in synchronism with the formation of the toner image on the photosensitive drum 1, the recording material conveying means such as the sheet feeding roller 15 and the conveying roller pair 16a from the cassette 14 which is the recording material accommodating portion is connected to the photosensitive drum 1. The recording material P is conveyed to the transfer portion T, which is a portion facing the transfer roller 9 as the transfer means.

Then, in the transfer section T, the photosensitive drum 1
The upper toner image is electrostatically transferred onto the recording material P. The recording material P on which the toner image has been transferred is conveyed to the fixing device 11, where the unfixed toner image carried on the surface is fused and fixed by heat and pressure, and becomes a permanent image. After that, the recording material P is conveyed by the paper ejection roller 16b or the like and ejected to the outside of the machine. Also, after the toner image is transferred, the photosensitive drum 1
The toner remaining on the surface (transfer residual toner) and the like is provided with a cleaner 10 having a cleaning means in the form of a blade.
The photosensitive drum 1 is repeatedly subjected to image formation.

Next, with reference to FIGS. 2 and 3, the developing device 2 of this embodiment will be described. In the drawings, elements having the same configurations and operations as those of the conventional example described above are designated by the same reference numerals.

FIG. 2 schematically shows a cross section of the developing device 2, and FIG. 3 schematically shows the developing device 2 as viewed from the photosensitive drum 1 side. In this embodiment, the developing roller 21 and the photosensitive drum 1 are not in contact with each other. Similar to the conventional developing device 2A described with reference to FIG. 10A, the toner in the toner hopper 24 is generated by the stirring member 26 that rotates in the direction of the arrow in the drawing.
It is sent from the toner hopper 24 to the developing chamber 25. The toner sent to the developing chamber 25 is configured by providing a sponge layer such as urethane sponge on a core metal, and is configured by a coating roller 22 that rotates in the arrow direction in the figure, and is configured by a rigid body such as aluminum, SUS, or resin. It is supplied onto the developing roller 21 which rotates in the direction of the arrow in the figure.

The toner supplied onto the developing roller 21 is
Thin layer coating by a developing blade 23 as a developer layer thickness regulating member configured by providing a rubber or elastomer such as urethane rubber or silicon rubber on a support plate as an elasticity imparting member composed of phosphor bronze or SUS To be done. The developing roller 21 and the photosensitive drum 1 are held in a gap of 50 μm to 500 μm by a space member (not shown).
Further, at least at the time of development, a predetermined bias is applied to the developing roller 21 from a bias power source (not shown), the toner applied to the developing roller 21 is supplied to the photosensitive drum 1, and the toner formed on the photosensitive drum 1 is discharged. The latent image is developed into a visible image (toner image).

In this embodiment, the developing device 2 is a cartridge (developing cartridge) which can be attached to and detached from the main assembly A of the apparatus. The developing device 2 is detachably attached to the apparatus main body A via the attaching means 18 provided in the apparatus main body A. The developing device 2 is used as a standard currently used state,
It is designed assuming that an image is formed on an A4 or letter size recording material at an image printing rate of 4% to 5%.

The image forming apparatus 100 of this embodiment has a developer remaining amount detecting mechanism for detecting the remaining amount of the developer (toner) in the developing device 2, particularly in the toner hopper 24, and further, the developing roller. It has a counter means for counting the number of rotations of 21. When the number of revolutions of the developing roller 21 counted by the counter means reaches a predetermined number of revolutions while the presence of toner in the toner hopper 24 is detected by the developer remaining amount detecting mechanism,
Display that effect. Hereinafter, it will be described more specifically.

In this embodiment, the optical detection system described with reference to FIG. 10 is adopted as the developer remaining amount detection mechanism. That is, inside the toner hopper 24, optically transparent transparent members 27a and 27b are provided. The transparent members 27a and 27b are used for receiving the light emitted from the light emitting element 28 provided in the apparatus main body A, and the light receiving element 2 provided also in the apparatus main body A.
It is provided to detect the remaining amount of toner in the toner hopper 24 when the light is received by the light source 9. That is, the irradiation light from the light emitting element 28 is irradiated in the direction of the arrow in the figure, but when the toner is sufficiently in the toner hopper 24, the toner blocks the irradiation light and is not received by the light receiving element 29. When the toner in the toner hopper 24 becomes low, the irradiation light is not blocked by the toner and is received by the light receiving element 29. The detection output of the light receiving element 29 is the device body A.
It is transmitted to the CPU board 12, which is the control means provided in the. When the CPU board 12 determines from the output of the light receiving element 29 that there is no toner in the toner hopper 24,
Transmitting means for displaying a signal to that effect on the display unit 13 provided in the apparatus main body A or for displaying the effect to an external host device (not shown) communicatively connected to the apparatus main body A Send by. The CPU board 12 may be a control circuit that integrally controls the operation of the image forming apparatus 100, and a CPU control circuit that includes a normal storage unit, a calculation unit, and a control unit may be used.

Further, the developing device 2 has a rotation counter 3 for directly counting the number of revolutions of the developing roller 21 via a gear mechanism as a counter means for counting the number of revolutions of the developing roller 21. In the present embodiment, the rotation counter 3 is provided on one side surface of the developing device 2 in the longitudinal direction (direction substantially orthogonal to the conveying direction of the recording material P).

The rotation counter 3 is shown in FIGS. 4 (a) and 4 (b).
As shown in FIG. 3, a reduction gear train 31, a display member 32, and a housing 33 that support these are provided, each rotating in the direction of the arrow in the drawing. Gear 30 shown in FIGS. 3 and 4.
Is fixed to the developing roller 21, and the developing roller 21
And the display member 32 is driven via the reduction gear train 31 and the reduction gear train 31. (The gears in the drawing have teeth omitted. In the reduction gear train 31, some gears are omitted. Except for, the gear train in the middle is abbreviated with a dotted line).

Finally, the display member 32 is sufficiently decelerated and rotates in the direction of the arrow in the figure. In addition, a part of the display member 32 has a color different from that of the other part as a detection part 32a. In this embodiment, the detector 32a is black and the other parts are white. As a result, the photo sensor 4 described later
Then, the detection unit 32a can detect.

An opening 34 is provided in a part of the housing 33 so that the detection portion 32a of the display member 32 is exposed. Figure 4
(A) shows the initial state of the developing device 2, and the housing 3
A white portion of the display member 32 is exposed in the opening 34 of No. 3. With the rotation of the developing roller 21, the display member 32 rotates in the direction of the arrow in the figure, and finally the state shown in FIG.
FIG. 4B shows a state in which the number of rotations of the developing roller 21 has reached a predetermined value, and the black detection portion 32 a of the display member 32 is exposed in the opening 34 of the housing 33.

As shown in FIG. 3, the apparatus main body A has a photo sensor 4 as a means for detecting (recognizing) the rotation speed information of the developing roller 21 transmitted by the display member 32. That is, the display member 32 is a light emitting element 41 such as an LED that irradiates the display member 32 of the rotation counter 3 with light.
And a light receiving element 42 such as a photodiode or a phototransistor that detects reflected light from the display member 32, and the photosensor 4 provided in the apparatus main body A detects the light. The detection output of the photo sensor 4 is transmitted to the CPU board 12.

Referring also to FIG. 5, when the image forming apparatus 100 is forming an image, the developer remaining amount detecting mechanism detects the toner remaining amount in the toner hopper and the counter means performs the developing operation. The number of rotations of the roller 21 is constantly counted.

Then, in the state shown in FIG. 4B, that is, in the state where the detecting portion 32a of the display member 32 is located in the opening 34 of the casing 33 and the photosensor 4 detects the detecting portion 32a, When the developer remaining amount detecting mechanism detects that the toner in the toner hopper 24 still remains, the CPU board 12 may cause the developing device 2 to print a lot of low-printed images, which may deteriorate the toner. It is determined that there is a state, and the display unit 13 displays that effect, and the operator is notified of the image quality deterioration. Further, a signal for displaying that fact may be transmitted by the transmission means to an external host device (not shown) communicatively connected to the apparatus main body A.

In this case, the operator, for example, only the line drawing,
If an acceptable image is printed even if image deterioration occurs, printing is continued, and if a photographic image for which image quality is desired is printed, the developing device 2 may be replaced.

The replaced developing device 2 can be used without waste if it is used for printing an image such as a line drawing which can be tolerated even if image deterioration occurs.

On the other hand, the image printing rate of 4 to 4 which maintains the image quality.
When an image of 5% or more is printed, the toner in the toner hopper 24 is exhausted before the detection unit 32a of the display member 32 of the rotation counter 3 is detected by the photosensor 4, so that the remaining amount of the developer is detected. Using the detection result, the operator is notified of the replacement time of the developing device 2 as described above.

Here, the display member 32 of the rotation counter 3
According to the study by the present inventors, the number of rotations of the developing roller 21 detected by the detection unit 32a of A is 4 to 4 when the standard developer is used and the image printing rate of the recording material P is A4 or letter size.
It may be set to 2 to 10 times the number of rotations of the developing roller 21 when 5% printing is performed. Of course, this is appropriately selected depending on the toner used and the image quality that is acceptable, and is not limited to this value.

The display member 32 may be directly recognized from the outside of the image forming apparatus, and in this case, the photo sensor 4 becomes unnecessary.

As described above, according to the present embodiment, it is detected by the developer remaining amount detecting mechanism that there is a developer remaining amount, and
Developing roller 21 counted by counter means
When the number of rotations of is reaching 2 to 10 times that of using the standard developer, by displaying that fact, the operator can recognize that image deterioration may occur, and high image quality can be obtained. When printing an image that requires printing, the developing device 2 can be replaced before printing, and when high image quality is not required, the developing device 2 can be used as it is by using the developing device as it is. Can be used. Further, when an image having a normal printing rate or a high printing rate is printed, it is possible to accurately know the replacement time of the developing device 2 by the developer remaining amount detecting mechanism. Further, by providing the detachable developing device 2 with the counter means, the developing device 2 itself can hold the rotation speed information of the developing roller 21, and, for example, the developing device 2 is reattached to the main assembly A of the apparatus. Even in such a case, the number of rotations of the developing roller 21 of each developing device 2 can be detected on the device main body A side based on the information held by the developing device 2.

Embodiment 2 Next, another embodiment of the present invention will be described with reference to FIGS. 6 and 7. FIG. 6 is an image forming apparatus according to this embodiment, and FIG.
Shows a schematic configuration of the developing device of this embodiment. The basic configuration and operation of the image forming apparatus according to the present exemplary embodiment are similar to those of the first exemplary embodiment. Therefore, elements having the same configurations and operations as those of the first exemplary embodiment are designated by the same reference numerals, and detailed description thereof will be given. The description is omitted.

In this embodiment, as the counter means for counting the number of rotations of the developing roller 21, a storage means for storing the number of rotations is used. Hereinafter, it will be described more specifically.

As shown in FIGS. 6 and 7, the developing device 2
Has an electric or magnetic storage means 5 for storing the number of rotations of the developing roller 21. Specifically, for example, RAM
Alternatively, electric storage means such as a rewritable ROM, magnetic storage means such as a magnetic recording medium, a magnetic bubble memory, or a magneto-optical memory can be used. In the present embodiment, the NV (Non
Volatile) RAM was used. NVRAM5
Is provided on the outer frame (upper wall) of the developing device 2 in this embodiment.

Here, the number of rotations of the developing roller 21 stored in the NVRAM 5 may be obtained by accumulating the rotation time of a drive motor (not shown) for rotating the developing roller 21, or printing in the rotating direction of the developing roller 21. The product of the image size ratio and the number of printed sheets may be accumulated. Here, the latter method using the number of printed sheets was used. Counting the number of rotations of the developing roller 21 also includes detecting information that changes according to the number of rotations of the developing roller 21 in this way. Table 1 shows the ratio of print image sizes.

[0051]

[Table 1]

That is, the print image size may be obtained from the image data, but here it is obtained from the size of the recording material P to be printed. Since the rotation time of the developing roller 21 is proportional to the size of the recording material P, for example, A4 size vertical feed is 1
If so, A5 size vertical feed is 210 mm / 297 mm =
0.7 (Table 1 describes all cases of vertical feed). This can be multiplied by the number of prints and accumulated. Usually, the life of the developing device 2 is specified when using a standard developer in which a printed image having an image printing rate of 4 to 5% is printed on the recording material P of A4 size (or letter size) which is most frequently used. Usually, it is set to 5,000 to 10,000 sheets. Taking 5000 sheets as an example, when the cumulative count of the number of rotations of the developing roller 21 reaches the 10000 to 50000 sheets which is 2 to 10 times as large as this, the toner hopper 24
If the toner inside is left, the operator may be notified.

The NVRAM 5 is connected to the CPU board 12 of the apparatus main body A via a connector 51 connected to the NVRAM 5 and a connector 52 provided in the apparatus main body A fitted with the connector 51. Then, every time image formation is performed, the CPU 100 determines the number of rotations of the developing roller 21 calculated by the above method through the connectors 51 and 52.
The VRAM 5 is cumulatively stored. Further, the cumulative number of rotations stored in the NVRAM 5 is fetched into the CPU board 12 via the connectors 51 and 52, for example, when the power of the apparatus main body A is turned on. The connector 52 constitutes a means for writing the rotation speed of the developing roller 21 into the NVRAM 5 as a counter means, reading the information, and detecting (recognizing) the rotation speed information of the developing roller 21. Then, when the cumulative number of rotations of the developing roller 21 reaches a predetermined number of rotations in a state where the remaining toner amount is detected in the toner hopper 24 by the developer remaining amount detection mechanism as described above, the operator To warn.

As described above, according to this embodiment, in addition to the effect described in the first embodiment, the counter means, which is the NVRAM 5, can be arranged not only in the vicinity of the developing roller 21 but also in any place, and further, it is complicated. Since a special gear train is not required, the device can be downsized.

Embodiment 3 Next, still another embodiment of the present invention will be described. FIG. 8 shows the image forming apparatus 20 of this embodiment.
A schematic configuration of 0 is shown. In this embodiment, the image forming apparatus 20
Reference numeral 0 is a color image forming apparatus including a plurality of developing devices 2 (2a, 2b, 2c, 2d) and capable of forming a full-color image. Each of the developing devices 2a, 2b, 2c and 2d contains yellow, magenta, cyan and black developers (toners), and is detachably mounted on a rotatable support (mounting means) 8.

The image forming apparatus 200 has an organic cylinder (OPC) or A-Si, Cd on the outer peripheral surface of an aluminum cylinder.
It has a photosensitive drum 1 as an image carrier formed by applying a photoconductor made of S, Se or the like. Photosensitive drum 1
Is driven in a direction indicated by an arrow by a driving unit (not shown), and is uniformly charged to a predetermined potential by a charging roller 6 as a charging unit. Then, by the exposure device 7, the first
As a color, light based on a signal according to, for example, a yellow image pattern is scanned on the photosensitive drum 1 to form a latent image on the photosensitive drum 1. When the photosensitive drum 1 further advances in the direction of the arrow,
Developing devices 2a, 2b, 2c, 2d supported by the support 8
Of these, the support 8 rotates so that the developing device 2a containing the yellow toner faces the photosensitive drum 1,
The latent image formed on is visualized by the selected developing device 2a.

Then, the developed yellow toner image is
It is transferred onto the intermediate transfer member 9. The intermediate transfer member 9 is EPD.
A transfer belt 91 made of rubber such as M, NBR, urethane, or silicon rubber is used as a driving roller 92 and a driven roller 9.
3, tension roller 94 is stretched over three rollers. Then, the transfer belt 91 is driven in the direction of the arrow in the figure by rotating the drive roller 92 in the direction of the arrow in the figure by a motor (not shown) that is a drive unit. A primary transfer roller 95 as a primary transfer unit having a conductive sponge layer on its shaft is provided at a position where it abuts on the photosensitive drum 1 via the transfer belt 91. A bias is applied to the primary transfer roller 95 from a high voltage power source (not shown), and the toner image on the photosensitive drum 1 is transferred onto the transfer belt 91.
Transcribed on. Further, the transfer residual toner on the photosensitive drum 1 is cleaned by the cleaner 10.

By sequentially performing the above steps for magenta, cyan and black, toner images of a plurality of colors are superposed and transferred onto the transfer belt 91. When the four color toner images are transferred onto the transfer belt 91, the recording material P is conveyed in synchronization with the movement of the transfer belt 91. Then, a secondary transfer roller 96 as a secondary transfer means having the same structure as the primary transfer roller 95 contacts the transfer belt 91 via the recording material P, and the secondary transfer roller 96 has a high voltage power source (not shown). No.), the four color toner images on the transfer belt 91 are collectively transferred onto the recording material P.

The recording paper P on which the four color toner images have been transferred is
It is melted and fixed by a conventionally known heating and pressure fixing device 11 to obtain a color image. Further, the transfer residual toner on the transfer belt 91 is cleaned by a cleaning device 97 such as a fur brush or a web which can be contacted and separated.

In the image forming apparatus 200 of this embodiment,
The developing devices 2a, 2b, 2c, 2d have the same configuration as the developing device 2 of the second embodiment described with reference to FIG.

That is, each developing device 2a, 2b, 2c, 2
d is each of the developing rollers 21a, 21b, 21c,
NVRAMs 5a, 5b, 5 for storing the rotation speed of 21d
c, 5d. And in this embodiment, the support 8
The N provided in each developing device 2a, 2b, 2c, 2d.
Connectors 52a, 52b, 52c and 52d are provided which are connected to the VRAMs 5a, b, c and d, respectively. Through the connectors 52a, 52b, 52c, 52d, the CPU boat 12 and N for controlling the apparatus main body A
The VRAMs 5a, 5b, 5c and 5d are connected.

Further, the image forming apparatus 200 is the same as that in the first and second embodiments.
It has the same developer remaining amount detection mechanism as in. In the present embodiment, the light emitting element 28 and the light receiving element 2 of the developer remaining amount detecting mechanism.
9 is provided on the support 8 for each of the developing devices 2a, 2b, 2c, 2d (only the developing device 2 for yellow is shown).

The CPU boat 12 receives the developing rollers 2 of the developing devices 2a, 2b, 2c and 2d from the NVRAMs 5a, 5b, 5c and 5d when the power of the main assembly A of the device is turned on.
The current rotational speeds of 1a, 21b, 21c and 21d are read respectively. At this point, it is detected by the developer remaining amount detecting mechanism that toner remains in the toner hopper 24, and the NVRAMs 5a, 5b, 5c, 5d are detected.
If there is a developing device in which the number of rotations of the developing roller 21 read from the printer has reached a predetermined number of rotations, the CPU board 12
Displays that fact on the display unit 13.

On the other hand, when the value is less than the predetermined value, the printing is started and the developing devices 2a, 2b, 2c, 2
Start counting the number of rotations of the developing rollers 21a, 21b, 21c, 21d of d and display the new cumulative current number of rotations in NVRAM.
Write to 5a, 5b, 5c and 5d. Then, similarly to the above, regarding the developing device 2 in which the cumulative number of rotations reaches a predetermined value in the state where the toner is present in the toner hopper 24, that effect may be displayed.

Further, when there is the developing device 2 in which the amount of toner remaining in the toner hopper 24 is detected by the light emitting element 26 and the light receiving element 27 and the absence of toner is detected, priority is given to the display of the rotation speed of the developing roller 21. And display that effect.

Developing rollers 21a, 21b, 21c, 21
The method of counting the number of rotations of d is the same as that in the second embodiment.
That is, the number of rotations of the developing rollers 21a, 21b, 21c, 21d may be accumulated by the rotation time of a drive motor (not shown) for rotating the developing rollers 21a, 21b, 21c, 21d. , 21c, 21
The product of the ratio of the printed image size in the rotation direction of d and the number of printed sheets may be accumulated. In this example, the method using the number of printed sheets was used. When the standard developer is used, the image printing rate is 4 to 5% with the recording material P of A4 size or letter size.
2 to 10 with respect to the rotation speed of the developing roller 21 when printing
When the cumulative number of rotations of the developing roller 21 has reached twice (10,000 to 50,000 sheets), the operator is notified when there is toner remaining.

In this embodiment, the color image forming apparatus 200 is used.
In the above, the case where the number of rotations of the developing roller 21 is counted using the NVRAM 5 has been described, but it goes without saying that the counter using the gear train shown in the first embodiment can also be used.

As described above, according to the present embodiment, by applying the present invention to the color image forming apparatus 200 having a plurality of developing devices 2, the same effects as those of the above-described respective embodiments can be obtained for the developing devices 2 of each color. In particular, with respect to the color developing device 2 which is highly likely to repeat image formation with a low image printing rate and requires high image quality, the operator is informed that image deterioration has occurred. Therefore, the developing device 2 can be effectively used, and a good color image can always be formed.

In each of the above-described embodiments, the operator is warned when the number of rotations of the developing roller 21 which is 2 to 10 times that of the standard developer is used. However, for example, the display level is within that range. It is also possible to provide a plurality of units and display the possibility of image deterioration step by step in a timely manner.

In each of the above-described embodiments, the system using light is described as the developer remaining amount detecting mechanism, but the present invention is not limited to this, and a conventionally known system using electrostatic capacity detection or a piezo element may also be used. You can

The developer remaining amount detecting mechanism may be one that detects a state where there is no developer, or one that can sequentially detect the developer remaining amount. The sequential detection of the remaining amount of the developer is not limited to sequentially detecting the entire range of 100% to 0% when the unused state of the developer is 100% and the state without the developer is 0%. For example, it includes sequentially detecting in the range of 50% to 0%. Further, the absence or 0% of the developer means that not only the developer in the developing device is completely exhausted but also the developer remains, but the developer is reduced to the extent that a predetermined quality image cannot be formed. Also includes. Therefore, the presence (remaining) of the developer in the developing device is a state from the start of use of the developing device to a preset no-developer state.

In each of the above embodiments, the non-contact developing device was used, but it goes without saying that it can be used in the contact developing device shown in FIG. 10 (b).

Further, in each of the above embodiments, the fact that image deterioration may occur is displayed on the display unit 13 or the external host device communicatively connected to the apparatus main assembly A.
Here, the display is not limited to the display on the operation panel of the image forming apparatus or the display screen of the external host device. For example, it may be notified by a warning sound, a voice, or the like, or may be recorded on the recording material P and output.

Further, in each of the above embodiments, the developing roller 21
The case where the developing device 2 in which the developing chamber 25 that holds the developing means such as the above and the toner hopper that is the developer accommodating portion are integrally formed is a cartridge that is attachable to and detachable from the apparatus main assembly A has been described. However, the present invention is not limited to this. In the present invention, the developing device includes a charging unit,
It is equally applicable to at least one of the cleaning means and the process cartridge integrally formed with the electrophotographic photosensitive member, and the same effect as described above can be obtained.

For example, as shown in FIG. 9, the developing device 2 described in the first embodiment is integrally made into a cartridge by the frame 17 together with the photosensitive drum 1, the charging roller 6 and the cleaner 10, and the developing device 2 is mounted on the main assembly A of the apparatus. The process cartridge B can be detached. The process cartridge B is detachably attached to the apparatus main body A via the attaching means 18 provided in the apparatus main body A. Even in the image forming apparatus to which the process cartridge B can be attached and detached, similarly to the first embodiment, there is a possibility that image deterioration may occur based on the detection results of the developer remaining amount detection mechanism and the counter unit. The operator can be notified. As a result, the operator can take action such as temporarily replacing the process cartridge B in accordance with a desired output image. Here, the entire description of the above-mentioned embodiment is cited for the control itself for performing such notification. Similarly, it goes without saying that the developing device 2 described in the second embodiment can be configured as a process cartridge.

[0076]

As described above, according to the present invention,
It is possible to notify the operator that there is a possibility that a predetermined quality image may not be formed in the state where there is a remaining amount of the developer.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a schematic configuration diagram of a developing device used in the image forming apparatus of FIG.

FIG. 3 is a diagram of the developing device in FIG. 2 viewed from a photosensitive drum side.

FIG. 4 is a schematic view of an embodiment of counter means using a gear train.

FIG. 5 is a flow chart for explaining an example of operations of a developer remaining amount detecting mechanism and a counter unit.

FIG. 6 is a schematic configuration diagram of another embodiment of the image forming apparatus according to the present invention.

7 is a schematic configuration diagram of a developing device used in the image forming apparatus of FIG.

FIG. 8 is a schematic configuration diagram of another embodiment of the image forming apparatus according to the present invention.

FIG. 9 is a schematic configuration diagram of still another embodiment of the image forming apparatus according to the present invention.

FIG. 10 is a schematic configuration diagram of a conventional (a) non-contact type developing device and (b) a contact type developing device.

[Explanation of symbols]

1 Photosensitive Drum (Image Carrier, Electrophotographic Photosensitive Member) 2 Developing Device 3 Rotation Counter (Counter Means) 4 Photo Sensor 5 NVRAM (Counter Means) 52 Connector

Continued front page    F-term (reference) 2H027 DA45 DD02 DE02 DE07 DE10                       EE08 EJ08 EJ13 EJ15 GB03                       GB07 GB11 HB02 HB13                 2H077 AA20 AB04 AB13 AC04 AD02                       AD06 AD13 AD23 AD35 DA15                       DA24 DA36 DA64 DB10 EA14                       EA16 FA13 GA03 GA04 GA13

Claims (14)

[Claims] 1. A developing device having a rotating developer carrier and a developer accommodating portion, and at least a part of a developer residual amount detecting mechanism for detecting a residual amount of the developer in the developer accommodating portion. And a counter means for counting the number of rotations of the developer carrying member. 2. The counter means rotates with the rotation of the developer carrier, which rotates with the rotation of the developer carrier, and with the rotation of the developer carrier through the gear train, and the rotation of the developer carrier. The developing device according to claim 1, further comprising a display member capable of transmitting numerical information. 3. The developing device according to claim 2, wherein the display state of the display member changes when the number of rotations of the developer carrier reaches a predetermined number of rotations. 4. The developing device according to claim 3, wherein the predetermined number of revolutions is a number of revolutions of the developer carrying member which is 2 to 10 times that of the standard developer. 5. The developing device according to claim 1, wherein the counter means is an electrical or magnetic storage means. 6. An image forming apparatus having a developing device including a rotating developer carrier and a developer accommodating portion,
A developer remaining amount detecting mechanism for detecting the remaining amount of the developer in the developer accommodating portion, a counter means for counting the number of rotations of the developer carrier, and a developer remaining by the developer remaining amount detecting mechanism. Is detected and the number of rotations of the developer carrying member counted by the counter means reaches a predetermined number of rotations, a control means for generating a signal to that effect is provided. An image forming apparatus characterized by. 7. The image forming apparatus according to claim 6, wherein the predetermined rotation speed is a rotation speed of the developer carrier that is 2 to 10 times that of the standard developer. 8. The gear train rotating with the rotation of the developer carrying member and the gear train rotating with the rotation of the developer carrying member via the gear train to rotate the developer carrying member. 7. A display member capable of transmitting numerical information, the image forming apparatus further comprising a detection unit for detecting rotational speed information of the developer carrier transmitted by the display member. Alternatively, the image forming apparatus of 7. 9. The display member according to claim 8, wherein the display state detected by the detection member changes when the number of rotations of the developer carrying member reaches the predetermined number of rotations. Image forming device. 10. The counter means is an electrical or magnetic storage means, and the image forming apparatus further has a means for electrically or magnetically writing the rotational speed of the developer carrying member in the storage means. 6. The method according to claim 6 or 7, wherein
Image forming device. 11. The image forming apparatus according to claim 6, further comprising display means for displaying information according to the signal generated by the control means. . 12. The apparatus according to claim 6, further comprising means for transmitting the signal generated by the control means to an external device communicatively connected to the image forming apparatus main body. The image forming apparatus according to the section. 13. The image forming apparatus according to claim 6, wherein at least the developing device is a cartridge that can be attached to and detached from the apparatus main body. 14. The image forming apparatus according to claim 13, wherein at least a part of the developer remaining amount detecting mechanism and the counter unit are provided in the developing device.