JPH0643706A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain an image forming device with a developing device, having the fitting of the specified number cartridge corresponding to the life of a photosensitive body, so that a cartridge can not be exchanged after that, without requiring a display to show fitting order on a toner cartridge, the complication of a constitution, etc. CONSTITUTION:In the image forming device attachably/detachably supporting a process unit provided with a process unit main body 1 obtained by unitizing the photosensitive body and the developing device constituting an image forming part by an electrophotographic system, and the toner cartridge 2 attachably/ detachably fitted to the process unit main body 1, a counting means 33 stepped by the fitting of the toner cartridge 2 and restraining means 35 and 26d operated when the counting means 33 is stepped by prescribed times, to lock the toner cartridge 2 and restraining the process unit so as not to exchange are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, in an electrophotographic image forming apparatus having a photoconductor drum which is replaced together with a developing device at the end of its life, prohibits attachment / detachment and replacement of a toner cartridge at the end of the life of the photoconductor. To an improved developing device.

[0002]

2. Description of the Related Art In an image forming apparatus using an electrophotographic process such as a copying machine, a printer, a facsimile machine, a latent image formed on a photoconductor is visualized by adhering toner from a developing device, An image is formed by transferring and fixing a visible image on a recording paper.

The photoconductor in the image forming unit is removed from the main body of the apparatus and replaced when the life of the photoconductor is reached. Recently, however, peripheral units such as a developing unit and a cleaning unit are not the photoconductor alone but a common process unit. In many cases, it has been made possible to be integrated and replaced. Particularly in a small personal type image forming apparatus, the toner life (toner amount) in the developing device is set so that the life of the photoconductor and the life of the photoconductor and the unitized development device correspond to each other. Consideration is given to the life of the. Therefore, running out of toner means that the process unit itself has reached the end of its life.

In such a conventional process unit system, the developing device can be sufficiently miniaturized as long as the life of the photoconductor is about several K sheets, but due to the improvement of the performance of the photoconductor, a long life of several tens of K sheets or more is achieved. If the toner storage amount on the developing device side is increased accordingly, the size of the process unit is increased. Therefore, a toner cartridge for replenishment can be attached to and detached from the developing device according to the life of the photoconductor. Recently, a method has been adopted in which the process unit is replaced when the toner is exhausted after the cartridge is replaced a predetermined number of times. According to this method, it is possible to greatly improve the print cost per copy.

As a conventional photoreceptor life notification means, a counter for counting the number of prints is provided on the apparatus main body side, and when the specified number of prints is counted, the life of the life is notified by a display on the operation unit or the like. Met. Similar to the conventional image forming apparatus, even in the image forming apparatus adopting the above-mentioned cartridge exchange system, the operator is notified of the fact that the process unit has reached the end of its life or just before it reaches the end of its life. It will be necessary to take measures such as stopping. As a conventional specific notification method, the order of use is displayed on a predetermined number of cartridges (for example, 5 cartridges) according to the life of the photosensitive member, and only the cartridge to be used last is replaced after the completion of mounting. A mechanical lock mechanism for prohibiting the above is provided, and the replacement of the process unit is displayed at the time of the toner end of the last cartridge (Japanese Patent Laid-Open No. 63-75756). According to this method, the toner end of the last cartridge reaches the end of the life of the unit itself, and the operator can recognize the life because replacement of the cartridge is impossible, but in reality it is not easy to manage the order of the cartridges. If the last cartridge is attached out of order, the process unit may become unusable before the end of its life.

[0006] In Japanese Utility Model Laid-Open No. 61-124052, a counting means that advances each time a toner cartridge is mounted in a developing device, and a prohibiting means that operates when a cartridge corresponding to the end of a prescribed number of replacements is mounted are activated. However, there is a drawback in that the configuration becomes complicated, although a configuration in which mounting after that is prohibited is disclosed.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is not necessary to provide an indication of the mounting order on the toner cartridge or to complicate the configuration, and the specified number of toner cartridges corresponding to the life of the photosensitive member can be obtained. An object of the present invention is to provide an image forming apparatus including a developing device in which the cartridge cannot be replaced after the cartridge is mounted.

[0008]

To achieve the above object, the first invention of the present application is to provide a process unit main body in which a photosensitive member and a developing device forming an electrophotographic image forming unit are unitized, and to the process unit main body. In the image forming apparatus, which detachably supports a process unit including a toner cartridge detachably attached to the process unit, the process unit main body is provided with a counting unit that advances by attachment of the toner cartridge, and the counting unit. The toner cartridge is activated when the means has stepped a predetermined number of times, and the toner cartridge is locked so as to be non-replaceable with respect to the process unit.

In the second aspect of the present invention, the toner cartridge side is provided with a restraint detection means which operates in conjunction with the operation of the restraint means, and the image forming apparatus main body side is provided with the presence or absence of the restraint detection means. It is characterized in that a sensor for detecting is provided.

In the third invention of the present application, the toner cartridge has a toner case which is mounted on the process unit main body and then rotated to align the replenishment opening with the opening of the developing device. On the outer peripheral surface of the toner case, a pressing claw for advancing the counting means and a lock hole are arranged along the circumferential direction, and the counting means is provided with a predetermined number of counting claws projecting along the circumferential direction on the outer circumference. The counting claw is configured to be rotated by one pressing claw by the pressing claw when the toner case is rotated, and a cam is fixed to the side surface of the counting means substantially coaxially. A groove is formed at one place on the outer peripheral surface of the cam, and a lever elastically biasing a hook portion at the tip toward the outer peripheral surface of the cam is rotatably supported near the counting means. The tip of the toner A lock lever that elastically fits into a lock hole on the outer peripheral surface of the case and locks the toner case to the process unit body is rotatably supported, and the toner cartridge of the same number as the total number of the counting claws is attached to the process unit body. When the final counting claw of the counting claws is pressed by the pressing claw, the tip of the lock lever is attached to the lock hole. And the toner case and the toner cartridge are constrained to the process unit.

In the fourth invention of the present application, a recognizing means is provided at an appropriate position on the side surface of the counting means or the cam, and when the mounting of the final toner cartridge is completed, the recognizing means is provided at the position of the process unit corresponding to the recognizing means. Is provided with an opening so that the recognition means can be seen through the opening.

According to a fifth aspect of the present invention, when the toner end of the developing device is detected after the lock lever restrains the final toner cartridge, the display unit displays the arrival of the process unit replacement time. It is characterized in that it is provided with a control unit.

The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic diagram of the overall configuration of a laser printer as an image forming apparatus to which the developing device of the present invention is applied. This device body 1
0 is composed of an upper structure 10a and a lower structure 10b,
The upper structure 10a is pivotally supported on the lower structure 10b by a shaft 11 so that the upper structure 10a can be opened and closed, and the photosensitive drum 12 is disposed at substantially the center of the apparatus main body 10. Around the photosensitive drum 12, a charging unit 13, a developing device 14, a transfer unit 15, and a cleaning unit 16 are arranged in order along the rotation direction indicated by the arrow. The optical writing means 18 is arranged below these electrophotographic process means, and the paper feed cassette 1 is further arranged below that.
Place 9

In the above structure, the recording sheet fed from the sheet feeding cassette 19 by the sheet feeding roller 20 is conveyed to the upper side of the photosensitive drum 12 at a timing by the registration roller pair 21. The photoconductor drum 12 is rotationally driven in the counterclockwise direction, the surface of the photoconductor drum 12 is uniformly charged by the charging unit 13, and the laser beam from the optical writing unit 18 is applied to the photoconductor drum 12 so that the electrostatic latent image is formed on the photoconductor drum 12. An image is formed. This latent image is visualized by the toner from the developing device when passing through the developing device 14. Then, this visible image is transferred by the transfer means 15 onto the lower surface of the recording paper conveyed to the upper side of the photosensitive drum 12. The transferred recording paper is conveyed to the fixing means 17, is heated and pressed between the fixing roller 17a and the pressure roller 17b to be fixed, and is conveyed to the paper ejection portion by the paper ejection roller 22, and is ejected to the paper ejection tray. 23
Stacked on top.

FIG. 2 is a schematic explanatory view of an electrophotographic process unit to which the present invention is applied, and FIG. 3 is a perspective view showing a state in which the toner cartridge is removed from the process unit. The photosensitive drum 12, the charging means 13, Developing device 1
The toner cartridge 2 is detachably attached to the unit main body 1 in which the waste toner conveying unit 24, the toner end sensor 4, and the toner end detection connector 25 are integrated. As shown in FIG. 3, the toner cartridge 2 includes a replenishment toner case 26 and a replenishment toner case 2.
6, a waste toner box 27 located on one end side, an agitator rotation gear box 28 located on the other end side, the waste toner box 27 and the agitator rotation gear box 2
8 and an integrated lever 29, the replenishment toner case 26 is supported rotatably in the arrow direction with respect to these integrated members.

A recess 14a for mounting a cartridge is formed in the developing device 14 which constitutes the process unit main body 1. Guided projections 29a at both ends of the lever 29 of the cartridge are formed on inner wall surfaces at both ends in the longitudinal direction of the recess 14a. A groove 1a for receiving is formed, and the guided projection 29 is formed in the groove 1a.
The cartridge 2 is mounted in the recess 14a by inserting a. The toner case 26 has a replenishment opening 26a. After the cartridge is mounted in the recess 14a in the posture shown in FIG. 3, the toner case 26 is rotated in the direction of the arrow to open the opening 26a as shown in FIG. It is fitted in the supply port 30 of 14. When the image forming process is started, the toner is supplied to the toner tank of the developing device 14 by the rotation of the agitator 3 as shown in FIG.

FIG. 4 shows a waste toner collecting means, which conveys between the waste toner conveying means 24 integrated with the process unit body 1 as shown in FIG. 4 and the waste toner box 27 of the toner cartridge 2. Connected by path 24a,
The waste toner is transferred into the box 27 by rotating the spiral transfer means in the transfer path.

FIGS. 5 and 6 are explanatory views of the structure of a lock mechanism which is an essential part of the present invention. FIG. 5 shows a state where the toner case is locked, and FIG. 6 shows a state immediately before being locked. . A pressing claw 31 is rotatably supported at its base end in a recess 26b formed at an appropriate position on the outer peripheral surface of the toner case 26 of the toner cartridge 2 (for example, both ends in the axial direction of the toner case). The tip portion is configured to be retractable inside and outside, and is urged by a spring 32 in the protruding direction. The pressing claw 31 has its base end portion restricted from rotating in the protruding direction by a stopper portion 26c which is a peripheral edge portion of the recess 26b. A lock hole 26d is formed below the recess 26b (downstream side in the rotation direction of the toner case 26 shown in FIG. 3).

Inside the mounting recess 14a of the developing device, there is provided a gear-like counting means 33 having a plurality of claws on the outer peripheral portion of the shaft 3.
It is supported in a unidirectional manner indicated by an arrow around 3A with a certain friction. The counting means 33 is arranged at a position facing the pressing claw 31. A cam 34 is integrated around the shaft 33A on the side surface of the counting means 33, and a groove 34a is formed on the outer peripheral surface of the cam 34. The groove 34a is formed at the same position as the fifth counting claw 33e. A shaft 40a located near the counting means 33
The base end portion of the lever 40 is pivotally supported on the lever 40, and the lever 40 is urged by a spring 37 so that the hook portion 40b at the tip thereof comes into pressure contact with the outer peripheral surface of the cam 34. The hook portion 40b locks the rotation of the counting means 33 by being fitted into the groove 34a. By forming five counting claws in the counting means 33, the maximum number of times the toner cartridge can be replaced is five in this embodiment. That is, the total number of counting claws is the same as the number of usable toner cartridges. Further, the lever 40 serves as a rotation stop for the counting means 33 by the hook portion thereof pressingly contacting the outer peripheral surface of the cam 34.

Further, a lock lever (restraint means) 35 is pivotally supported at its base end portion by a shaft 35a on the side of the lever 40, and a projection 35a at the tip end portion is spring-loaded by a spring 36 to a lock hole 26d on the outer peripheral surface of the toner case. It is elastically biased to fit inside. A gear portion is coaxially integrated with the shaft 35a, and the gear portion meshes with a gear 38a at a base end portion of a lock detection lever (restraint detection means) 38 rotatably provided on the process unit 1 side. And rotate it. On the image forming apparatus main body 10 side, a sensor 39 including a photo interrupter is fixed so as to project into the rotation path of the tip of the lock detection lever 38, and the lock lever is determined depending on whether the lever 38 operates the sensor 39 or not. The state of 35 is detected. The sensor 39 outputs a detection signal to a controller (not shown) provided on the apparatus body 10 side. The control unit provides necessary display on a display unit such as an operation unit (not shown).

When the first cartridge 2 is attached to the process unit main body 1, the first counting claw 33a of the counting means 33 is located at a position that is returned counterclockwise by about 180 degrees from the position shown in FIG. When the toner case 26 of the first cartridge is rotated in the direction of the arrow, the recess 26b
The pressing claw 31 protruding from the first counting claw 3
By depressing 3a, the counting means 33 is rotated clockwise by one counting claw 33a. When the first cartridge becomes the toner end and the second cartridge is mounted and the toner case is rotated in the same direction, the second counting claw 33b is pushed down by the pressing claw 31. The same operation is repeated until the third and fourth cartridge mounting operations, and the hook portion 40b of the lever 40 slides along the outer peripheral surface of the cam portion 34. When mounting the fifth cartridge, as shown in FIG. 6, the pressing claw 31 becomes the fifth counting claw 33.
When e is pushed down, as shown in FIG. 5, the hook portion 40b of the lever 40 is fitted into the groove 34a on the peripheral surface of the cam 34 to lock the counting means 33. At the same time, the lock lever 35 is fitted into the lock hole 26d so that the toner case 2
Lock 6 At a position having a predetermined positional relationship with the counting means 33 or the fifth counting claw 33e on the cam 34, a color label, a label displaying numbers, characters, etc., and a marking (recognition means) 41 are attached and formed. An opening is provided on the side of the process unit corresponding to the label 41 so that the display can be viewed through the opening when the process unit is taken out of the apparatus main body 10.

Further, in the locked state shown in FIG. 5, the lock detection lever 38 interlocked with the lock lever 35 is rotated to a position to shield the sensor 39, so that the control unit on the side of the device holder 10 is a process unit. You can see that the last cartridge was installed in. Further, the toner end detection connector 25 is connected to the connector 45 provided on the main body 10 side and notifies the control unit of the toner end. That is, when the fifth toner cartridge is installed and the control unit is notified that the toner case is locked, and when the toner end is detected, the control unit is a display unit such as an LCD installed on the main body side. Indicates the end of service life of the process unit. The pressing claw 31 and the counting means 3
3, the levers 40 and 35 constitute counting / constraining means, and the lock lever 35 and the lock hole 26d constitute cartridge restraining means.

[0023]

As described above, according to the present invention, the counting means for incrementing the number of times the toner cartridge is replaced with respect to the process unit main body including the photoconductor and the developing device, and the count value by the counting means are predetermined. Since the last toner cartridge is locked to the process unit main body side when the number of times has been reached, and a restraint means is provided to prevent subsequent replacement, the user can not replace the toner cartridge at the last time. Since it is a toner cartridge, it can be known that the life of the process unit is approaching.
The life of the process unit can be used up to the full life regardless of the life of the toner, and the economical efficiency per print can be improved. Further, since the counting / constraining means has a simple structure including the pressing claw 31, the counting means 33, and the levers 40 and 35, the toner cartridge is equipped with the waste toner collecting box, and the developing device on the process unit main body side is equipped with the waste toner collecting box. Since the waste toner collecting means is provided to collect the waste toner in the box, it is not necessary to store the waste toner from a plurality of cartridges exchangeably mounted inside the apparatus main body or the process cartridge main body side. It is convenient for downsizing.

After the cartridge has been exchanged a specified number of times, a means for detecting that the final toner cartridge is installed is provided, so that the user can be warned, the failed printing can be prevented, and the used process unit can be re-used. It is possible to prevent input.

At the time when the final cartridge is completely installed, a message indicating that the subsequent replacement is impossible is made from the outside of the process unit by color, numbers, characters, etc., so that the user can easily recognize it and re-insert the cartridge. This makes it easy to sort out printing mistakes and collection / reuse. Further, a detection signal from the sensor 39 which is activated when the means for restraining the toner cartridge to the process unit is input to the control section of the apparatus main body, and further, a signal which detects that the toner in the final toner cartridge is exhausted. Is sensor 2
Since the display indicating that the process unit should be replaced is displayed on the main body of the apparatus when an input is made from 5 to the control section, the user can be surely notified of the end of life.

[Brief description of drawings]

FIG. 1 is a schematic view of the entire configuration of a laser printer as an image forming apparatus to which a developing device of the present invention is applied.

FIG. 2 is a schematic configuration explanatory view of an electrophotographic process unit to which the present invention is applied.

FIG. 3 is a perspective view showing a state immediately before the cartridge is attached to the process unit main body.

FIG. 4 is a structural explanatory view of a waste toner collecting mechanism of the process unit.

FIG. 5 is a structural explanatory view of a lock mechanism which is a main part of the present invention, and is a view showing a state in which the toner case is locked.

FIG. 6 is a diagram showing a state in which the toner case is locked.

[Explanation of symbols]

1 Process Unit Main Body, 1a Groove, 2 Toner Cartridge, 10 Device Main Body, 10a Upper Structure, 10b
Lower structure, 11 axis, 12 photoconductor drum, 13 charging means, 14 developing device, 14a cartridge mounting recess, 15 transfer means, 16 cleaning means, 18
Optical writing unit, 19 paper feed cassette, 20 paper feed roller, 21 registration roller pair, 25 toner end detection connector, 26 replenishment toner case, 26a opening,
26b recess, 26d lock hole, 27 waste toner box, 28 agitator rotation gear box, 29 lever, 29a guided projection, 30 supply port, 31 pressing claw, 33 counting means, 33A shaft, 33a, 33b,
33e counting claw, 34 cam, 34a groove, 35 lock lever, 35a protrusion, 36 spring, 38 lock detection lever (restraint detection means), 39 sensor, 40 lever, 40a shaft, 40b hook part,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shingi Miyamoto 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. (72) Iwa Matsumae 1-3-6 Nakamagome, Ota-ku, Tokyo Shares Within Ricoh Company (72) Inventor Takahiro Tamiya 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Company, Ltd.

Claims (5)

[Claims] 1. A process unit main body comprising a photosensitive member and a developing device forming an electrophotographic image forming unit, and a toner cartridge detachably attached to the process unit main body. In an image forming apparatus in which a process unit is detachably supported, a counting unit that advances by mounting the toner cartridge on the process unit main body side, and the toner that operates when the counting unit advances a predetermined number of times. A developing device, comprising: a locking unit that locks the cartridge so that the process unit cannot be replaced. 2. The toner cartridge side is provided with a restraint detection means that operates in conjunction with the operation of the restraint means, and the main body of the image forming apparatus is provided with a sensor for detecting the presence or absence of the action by the restraint detection means. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. 3. The toner cartridge has a toner case for aligning a replenishment opening with an opening of the developing device by rotating after being attached to the process unit main body, and an outer peripheral surface of the toner case. In this case, a pressing claw for advancing the counting means and a lock hole are arranged along the circumferential direction, and the counting means has a configuration in which a predetermined number of counting claws are provided on the outer circumference along the circumferential direction and the counting is performed. The claw is configured to be rotated by one pressing claw by the pressing claw when the toner case is rotated, and a cam is fixed to the side surface of the counting means in a substantially coaxial manner, and at the outer peripheral surface of the cam. A groove is formed at one place, and a lever elastically biasing a hook portion at the tip toward the outer peripheral surface of the cam is pivotally supported near the counting means, and the tip portion is provided near the lever. To lock the outer surface of the toner case. A lock lever that elastically fits into the hole and locks the toner case to the process unit body is rotatably supported, and the same number of toner cartridges as the total number of the counting pawls are attached to the process unit body. When the toner case is rotated to complete the mounting and the last counting claw among the counting claws is pressed by the pressing claw, the tip end of the lock lever is fitted into the lock hole. The image forming apparatus according to claim 1, wherein the toner case and the toner cartridge are constrained to a process unit. 4. A recognition means is provided at an appropriate place on a side surface of the counting means or the cam, and an opening is provided at a position of a process unit corresponding to the recognition means when mounting of a final toner cartridge is completed. The image forming apparatus according to claim 1, wherein the recognition unit is visible through the opening. 5. A control unit is provided for displaying the arrival of the replacement time of the process unit on the display unit when the toner end of the developing device is detected after the lock lever restrains the last toner cartridge. The image forming apparatus according to claim 1, 2, 3, 4, or 5.