Process cartridge, development apparatus, and electrophoto-graphic image formation apparatus

Abstract: A process cartridge detachably mountable relative to a main assembly of an electrophotographic image forming apparatus, includes an electrophotographic photosensitive member; developing device for developing a latent image formed on the electrophotographic photosensitive member; a toner accommodating portion for accommodating toner to be used by the developing device to develop the latent image; a first toner feeding member for feeding the toner accommodated in the toner accommodating portion toward the developing device; a second toner feeding member for feeding the toner accommodated in the toner accommodating portion toward the developing device; wherein the second toner feeding member starts to operate in response to detection of decrease of a remaining amount of the toner accommodated in the toner accommodating portion to feed the toner accommodated in the toner accommodating portion toward the developing device.

Description: The present invention relates to a process cartridge, a development apparatus, and an electrophotographic image formation apparatus. In this specification, an electrophotographic image formation apparatus means an apparatus such as an electrophotographic copy machine, an electrophotographic printer (LED printer, laser beam printer, and the like), an electrophotographic facsimile apparatus, an electrophotographic word processor, and the like, which employ an electrophotographic image formation process to form an image on recording medium. A process cartridge means a cartridge which is removably mountable in the main assembly of an image forming apparatus, and in which at least one processing means among a charging means, a developing means, and a cleaning means is integrally disposed with an electrophotographic photosensitive drum, and a cartridge which is removably mountable in the main assembly of an image forming apparatus, and in which at least a developing means, and an electrophotographic photosensitive member, are integrally disposed. A conventional image formation apparatus employing an electrophotographic image formation process employs a process cartridge system in which an electrophotographic photosensitive member, and processing means which act on the electrophotographic photosensitive member, are integrally disposed in a cartridge which is removably mountable in the main assembly of an image forming apparatus. According to this process cartridge system, an image forming apparatus can be maintained without relying on service personnel; an image forming apparatus can be maintained by a user alone. Therefore, operational efficiency can be greatly improved. Thus, the process cartridge system is widely employed in the field of an image formation apparatus. EP-A-0514874 describes a cartridge for an image forming apparatus wherein multiple rotary conveyors are provided to transport toner to a developing station, the conveyors being driven from a power source external to the cartridge. Some of image forming apparatuses are provided with a means for detecting the amount of developer remaining. This detecting means issues a warning to a user before the amount of developer in the developer containing portion decreases to a critical point below which the apparatuses begin outputting a blurred image, that is, a low density image. The present invention was made as the results of further development of the above described conventional art. Accordingly, the primary object of the present invention is to provide a process cartridge, a development apparatus, and an electrophotographic image formation apparatus, which are capable of effectively dealing with decrease in the toner supply in the toner containing portion before it reaches a critical point. Another object of the present invention is to provide a process cartridge, a development apparatus, and an electrophotographic image formation apparatus, which comprise a means which begins to feed developer toward a development station as the amount of the toner in the toner containing portion decreases to a predetermined level. Another object of the present invention is to provide a process cartridge, a development apparatus, and an electrophotographic image formation apparatus, which are capable of consuming the toner contained in the toner containing portion, with high utilization efficiency. According to an aspect of the present invention there is provided a process cartridge detachably mountable to a main assembly of an electrophotographic image-forming apparatus, comprising: an electrophotographic photosensitive member; developing means for developing a latent image formed on said electrophotographic photosensitive member; a toner accommodating portion for accommodating toner to be used by said developing means to develop the latent image; a sensor for generating a signal when detecting the decrease of a remaining amount of the toner accommodated in the toner accommodating portion; a first toner feeding member for feeding the toner accommodated in the toner accommodating portion from a sweeping range of the first toner feeding member toward said developing means; and a second toner feeding member for feeding the toner accommodated in the toner accommodating portion toward said first toner feeding member; wherein said second toner feeding member starts to operate in response to the signal from said sensor, characterized in that: the second toner feeding member is arranged for movement by a driving energy source contained in said process cartridge itself to move the toner into the sweeping range of the first toner feeding member. According to a second aspect, there is provided developing apparatus detachably mountable to a main assembly of an electrophotographic image-forming apparatus for developing a latent image formed on an electrophotographic photosensitive member of the electrophotographic image-forming apparatus, the developing apparatus comprising: a toner accommodating portion for accommodating toner to be used by said developing means to develop the latent image; a sensor for generating a signal when detecting the decrease of a remaining amount of the toner accommodated in the toner accommodating portion; a first toner feeding member for feeding the toner accommodated in the toner accommodating portion from a sweeping range of the first toner feeding member towards a developing means; and a second toner feeding member for feeding the toner accommodated in the toner accommodating portion toward said first toner feeding member; wherein said second toner feeding member starts to operate in response to the signal from said sensor, characterized in that: the second toner feeding member is arranged for movement by a driving energy source contained in said developing apparatus itself to move the toner into the sweeping range of the first toner feeding member. A third aspect of the invention provides an electrophotographic image-forming apparatus for forming an image on a recording material, to which a process cartridge is detachably mountable, comprising: (a) a mounting portion for detachably mounting a process cartridge, said process cartridge including: an electrophotographic photosensitive member; developing means for developing a latent image formed on said electrophotographic photosensitive member; a toner accommodating portion for accommodating toner to be used by said developing means to develop the latent image; a sensor for generating a signal when detecting the decrease of a remaining amount of the toner accommodated in the toner accommodating portion; a first toner feeding member for feeding the toner accommodated in the toner accommodating portion from a sweeping range of the first toner feeding member toward said developing means; and a second toner feeding member for feeding the toner accommodated in the toner accommodating portion toward said first toner feeding member; wherein said second toner feeding member is operable in response to the signal from said sensor; wherein the second toner feeding member is arranged for movement by a driving energy source contained in said process cartridge itself to move the toner into the sweeping range of the first toner feeding member; and wherein the movement of said second toner feeding member is prevented by a releaseable locking member; (b) detecting means for detecting the remaining amount of the toner accommodated in said toner accommodating portion of said process cartridge; (c) a releasing member cooperable with the locking member of the process cartridge to permit the operation of the second toner feeding member in response to the detection of the decrease of remaining toner. A fourth aspect of the invention provides an electrophotographic image-forming apparatus as defined in claim 20. Embodiments of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a schematic sectional view of an embodiment of the image formation apparatus in accordance with the present invention, and depicts the general structure thereof. Figure 2 is a sectional view of the process cartridge in the first embodiment. Figure 3 is a schematic drawing of the developer conveying means of the process cartridge illustrated in Figure 2. Figure 4 is a circuit diagram for a toner remainder detection circuit in the image formation apparatus illustrated in Figure 1. Figure 5 is a graph showing the discrimination reference for the toner remainder detection circuit illustrated in Figure 4. Figure 6 is a sectional view of the process cartridge illustrated in Figure 2, and depicts a state of the process cartridge in which the developer conveying means is in operation. Figure 7 is a block diagram which shows the first no-toner detection. Figure 8 is a block diagram which shows the second no-toner detection, and Figure 9 is a sectional view of the development apparatus in the second embodiment of the present invention. Hereinafter, electrophotographic image formation apparatuses, process cartridges, and development apparatuses, which are in accordance with the present invention, will be described in detail with reference to the drawings. Embodiment 1 First, referring to Figures 1 - 8, the process cartridge in this embodiment, and an electrophotographic image formation apparatus compatible with such a process cartridge, will be described in detail. Referring to Figure 1, in image formation apparatus A (laser beam printer), a laser beam which is carrying image data is projected from an optical system 51 onto an electrophotographic photosensitive member 8 (hereinafter, photosensitive drum) in the form of a drum, and forms a latent image on the photosensitive layer thereof, and this latent image is developed into a toner image. In synchronism with the formation of the toner image, a recording medium P is fed out of a sheet feeder cassette 5, and is conveyed into the image forming station of a process cartridge B, by a conveying means comprising a pickup roller 53b, a conveyer roller pair 53c, conveyer roller 53d, and the like. In the image forming station, the toner image formed on the photosensitive drum 8 is transferred onto the recording medium P by applying voltage to a transfer roller 54 as a transferring means. Then, the recording medium P is conveyed, being guided by a guide plate 53f, to a fixing means 55. The fixing means 55 comprises a driver roller 55a, and a fixer roller 55c containing a heater 55b, and fixes the transferred toner image to the recording medium P by applying heat and pressure, as the recording medium P passes through the fixing means 55. Thereafter, the recording medium P is further conveyed through a reversing path, and is discharged into a delivery tray 56, by a discharge roller pair 53g and a discharge roller 53h. The process cartridge B comprises an electrophotographic photosensitive member, and at least one processing means. The processing means includes a charging means for charging the electrophotographic photosensitive member, a developing means for developing a latent image formed on the electrophotographic photosensitive member, a cleaning means for cleaning the toner remaining on the surface of the electrophotographic photosensitive member, and the like means. Referring to Figure 2, in the process cartridge B in this embodiment, a charger 11, an exposure opening 12 for allowing the laser beam to be projected onto the photosensitive drum 8, a developing means 4 for developing a latent image with the use of toner, and a cleaning means 9, are disposed around the electrophotographic photosensitive drum 8. These components are integrally disposed in a toner containing frame portion 1 as a developer containing portion, a development frame portion 2, or a cleaning frame portion. In other words, the process cartridge B is constructed by uniting the toner containing frame portion 1, the development frame portion 2 which supports the development roller 5 or the like, and the cleaning frame portion 3 which supports the photosensitive drum 8, the cleaning means 9, and the charger 11. The developing means 4, which uses magnetic toner as developer to form a toner image, comprises a toner storing portion 1 for holding toner. The toner storing portion 1 is provided with a toner feeding member 21, which is rotated in the direction of an arrow mark to feed the toner toward the development roller 5 as a developer carrier, while preventing the coagulation and local concentration of the toner. The development roller 5 contains a magnet 6 which attracts the toner supplied to the development roller 5 and holds it on the surface of the development roller 5. Further, an elastic blade 9 is placed in contact with the surface of the development roller 5 to form a thin layer of toner on the surface of the development roller 5 by regulating the thickness of the toner layer formed on the surface of the development roller 5. While the toner layer is formed on the development roller 5 as the development roller 5 is rotated, the toner becomes charged due to the friction between the toner and the rotating development roller 5, and obtains a sufficient amount of triboelectric charge to develop the electrostatic image on the photosensitive drum 8. In this embodiment, a voltage composed by superposing a DC component (approximately -500 V) upon an AC voltage component (Vpp is approx. 1600 V) is applied as a development bias to the development roller 5. The development roller 5 on which the aforementioned toner layer is formed, and the photosensitive drum 8, are positioned adjacent to each other, holding a microscopic gap (approximately 250 µm). This positional arrangement is realized by fitting the development roller 5 with contact rings (unillustrated) having a diameter larger, by the aforementioned microscopic gap, than the diameter of the development roller 5. More specifically, the rings are fitted around the development roller 5, adjacent to the corresponding axial ends, outside the toner layer formation region, and make contact with the photosensitive drum 8, on the regions outside the latent image formation region. Further, one of the axial ends of the development roller 5 is provided with a first helical gear (unillustrated) through which the development roller 5 receives a force which rotatively drives the development roller 5. The first helical gear is meshed with a second helical gear (unillustrated) fixed to the corresponding axial end of the photosensitive drum 8, so that the development roller 5 is rotated by the rotation of the photosensitive drum 8. Also, the first helical gear is meshed with a third helical gear (unillustrated) connected to the toner feeding member 21, so that the rotational force of the photosensitive drum 8 is also transmitted to the toner feeding member 21. It should be noted here that the second helical gear is the gear which meshes with a helical gear provided on the main assembly side of an image formation apparatus, to receive the driving force therefrom, and therefore, the toner feeding member 21 is also rotated by the rotation of the photosensitive drum 8. In other words, the toner feeding member 21 rotates as it receives the driving force from the main assembly of an image formation apparatus during image formation. A reference alphanumeric 21a designates an auxiliary toner feeding member, which rotates with the same timing as the toner feeding member 21. Next, referring mainly to Figures 2 and 3, the developer conveying means, which characterizes the present invention, will be described. The developer conveying means 30 is in the modified form of a crank and is disposed in the toner storing portion 1, outside the sweeping range of the toner feeding member 21. It comprises rotational axis portions 30a and 30a rotatively supported by the internal wall of the toner storing portion 1, arm portions 30b and 30b extending from the rotational axis portions 30a and 30a, a horizontal portion 30c connected to the arm portions 30b and 30b, and a flexible member 31 attached to the horizontal portion 30c. Referring to Figure 2, the arm portion 30b is bent so that the developer conveying means 30 remains substantially in contact with the ceiling portion of the toner storing portion 1 when not operating. The flexible member 31 is formed of a sheet of polyethylene terephthalate or rubber, for example. The rotational axis portion 30a, the arm portion 30b, and the horizontal portion 30c are formed of nonmagnetic metallic material or plastic resin. Referring to Figure 3, one of the rotational axis portions 30a and 30a is fitted with an operational spring 35 (torsional coil spring). One end of the operational spring 35 is attached to the wall of the toner storing portion 1, and the other end is attached to the arm portions 3b, to apply pressure to the developer conveying means 30 in the direction of the toner feeding member 21. The other rotational axis portion 30a is engaged with a claw portion 33a of a lever 33 which is put through the wall of the toner storing portion 1, to prevent the developer conveying means 30 from being rotated by the pressure from the operational spring 35, during the non-operational period of the developer conveying means. The lever 33 of the process cartridge 3 is in the form of a letter L, and is rotatively supported by a supporting member 1a at the middle of the vertical portion 33b connected to the claw portion 33a. One end of the vertical portion 33b, that is, the end opposite to the claw portion 33a, is provided with a spring member 1b which applies pressure to the vertical portion 33b in a manner to rotate the vertical portion 33b about the supporting member 1a in the counterclockwise direction. This arrangement keeps the claw portion 33a in contact with the arm portion 30b of the developer conveying means 30. The main assembly of the image formation apparatus is provided with a lever 32 and a solenoid 36. After the process cartridge is mounted in the apparatus main assembly, the lever 32 on the main assembly side is capable of pressing the vertical portion 33b of the lever 33 of the process cartridge B, on the surface opposite to the surface with which the spring member 1b is in contact. The solenoid 36 presses the lever 32 on the main assembly side. As described above, the toner feeding member 21 and the developer conveying means 30 are disposed within the toner storing portion 1, and the development roller 5 and the elastic blade 7 are attached to the development frame portion 2. The photosensitive drum 8, a primary charger 11, and the cleaning blade 10 are disposed in the cleaning frame portion 3. Further, the process cartridge B is provided with a drum shutter 25 which prevents the photosensitive drum 8 from being inadvertently exposed to light or damaged. This drum shutter 25 is automatically opened as the process cartridge B is mounted in the apparatus main assembly, and is automatically closed by the pressure from a spring (unillustrated) as the process cartridge B is removed from the apparatus main assembly. The developer conveying means 30 is activated in response to the detection of the decrease in the amount of the toner held in the toner storing portion 1, and feeds the toner held in the toner storing portion 1 toward the development roller 5. This action of the developer feeding means 30 is caused by the resiliency of the elastic member such as a coil spring or a compression spring. Further, the developing means 4 of this embodiment is provided with a toner remainder detecting means 26 for detecting the presence or absence of toner within the toner storing portion 1. Next, the structure of the toner remainder detecting means will be described. Referring to Figure 2, there is a metallic antenna wire 26 as an antenna member in the toner path through which toner is conveyed from the toner storing portion 1 to the development roller 5. It is fixed to the development frame portion 2 substantially in parallel to the metallic development roller 5. This antenna wire 26 and the development roller 5 are used as a first electrode and a second electrode, respectively, wherein voltage is applied between the two electrodes, and the presence or absence of the toner is detected by detecting the change in the electrostatic capacity between the two electrodes. In other words, when there is a sufficient amount of toner in the toner storing portion 1, toner is present between the two electrodes, and therefore, the electrostatic capacity between the two electrodes is large, but when toner disappears from between the two electrodes as toner is consumed, the electrostatic capacity between the two electrodes decreases. This change in the electrostatic capacity is detected by the toner remainder detection circuit provided on the apparatus main assembly side, and when the detected electrostatic capacity is below a predetermined value, it is determined that toner is absent. Figure 4 shows a toner remainder detection circuit 100 provided on the apparatus main assembly side. In this circuit 100, the circuit portion comprising the development roller 5 and the antenna wire 26 are equivalent to a condenser, wherein an AC voltage (Vpp is approx. 1600 V) having a rectangular waveform is applied to the development roller 5 from a high voltage power source HV provided in the apparatus main assembly. In reality, the waveform of the high voltage from the high voltage power source HV involves an inclination in its rising and falling portions, and is detected as a differential waveform ANT by the electrostatic capacity between the development roller 5 and the antenna wire 26, and resistors R1 and R2. A diode D1 is a clamping diode whose output is negative. The differential waveform ANT is divided by the resistances R1 and R2, and its peak is detected by a first peak hold circuit comprising an operational amplifier OA1, a diode D2, and a condenser C1, and is converted to a DC signal. A resistor R3 is provided for discharging the condenser C1. The electrostatic capacity between the development roller 5 and the antenna wire 26 is dependent on the amount of toner present between the development roller 5 and the antenna wire 26. That is, as the amount of the toner between two electrical conductors increases, the dielectric constant between the two conductors increases, which in turn increases the electrostatic capacity between the two conductors. Conversely, the dielectric constant between the two conductors decreases as the amount of the toner between the two conductors decreases, reducing thereby the electrostatic capacity between the two. Therefore, the voltage detected by the first peak hold circuit decreases as the amount of the toner decreases. On the other hand, the output from the high voltage power source HV is supplied to the development roller 5, and also to a differentiation circuit comprising a referential condenser C2, resistors R4, R5 (volume resistor), and R6. A diode D3 is a clamping diode whose output is negative. The differential waveform detected through the volume resistor R5 is converted into a DC signal by a second peak hold circuit comprising an operational amplifier OA2, a diode D4, the condenser C3, and a discharge resistor R7. The volume resistor R5 is adjusted so that the output from the second peak hold circuit matches a predetermined reference value (approximately 2.7 V in this embodiment). The output from the first peak hold circuit (potential of condenser C1 value proportional to the amount of the toner remainder), and the output from the second peak hold circuit (potential of condenser C3 referential value), are compared by a comparator CO1, and is outputted as a signal indicating the amount of the toner remainder. When there is a sufficient amount of toner between the development roller 5 and the antenna wire 26, the output of condenser C1 remains at a low level. Therefore, the amount of the toner remainder can be detected from the output of the comparator CO1. Figure 5 is a graph showing the relationship between the aforementioned electrostatic capacity and the amount of the toner in the toner storing portion 1, in which the axis of abscissas represents the amount of the remaining toner, and the axis of ordinates represents the electrostatic capacity. When there is toner between the two electrodes, the electrostatic capacity between the two electrodes is large, and as the amount of toner decreases, the electrostatic capacity decreases. Therefore, the change in electrostatic capacity is detected by the toner remainder detection circuit provided on the apparatus main assembly side, and when the detected electrostatic capacity drops below a predetermined value C, it is determined that the toner is absent. It should be noted here that even when it is determined based on the output of the toner remainder detection circuit 100 that toner is absent, toner T indicated by hatching in Figure 2 still remains in a space beyond the sweeping range of the toner feeding member 21, though the amount of toner T is very small. Figure 7 is a block diagram for toner remainder detection control. This diagram shows the control executed when the toner absence is detected first time. After it is determined by the toner remainder detecting means and the toner remainder detection circuit that toner is absent, an ON signal is sent through a solenoid driver circuit 200 to the solenoid 36 on the main assembly side of the image formation apparatus A illustrated in Figure 3, to move the lever 32. As a result, the lever 33 on the process cartridge side B is rotated, and the claw portion 33a is disengaged from the arm portion 30b of the developer conveying means 30. Consequently, the developer conveying means 30 rotates due to the pressure from the spring 35 having been wound to generate pressure to rotate the developer conveying means 30 in the direction of an arrow mark Y in Figures 2 and 6, and stops as it comes in contact with the stopper 30d. During this movement of the developer conveying means 30, its flexible member 31 conveys the remaining toner T in a manner to move it into the sweeping range of the toner feeding member 21. Then, the toner T is conveyed in the normal manner by the toner feeding member 21 toward the development station. More specifically, the toner remainder T is pushed out by the flexible member 31 along a slanted surface 1a sloped toward the toner feeding member 21, that is, one of the walls of the toner storing portion 1 (Figures 2 and 6 depict the state of the process cartridge B in the main assembly of the image formation apparatus A). Also during the rotational movement of the developer conveying means 30, the amount of the toner remainder in the toner storing portion 1 is extremely small, and therefore, the effect of the increased rotational load upon the main assembly of the image formation apparatus remains at an extremely low level. The detection of "toner absence" is stored, as cartridge-specific information, in a storing means 50 such as an RAM provided in the process cartridge B. This storing means 50 is capable of receiving information from the main assembly of the image formation apparatus A through an electrical contact (unillustrated) provided in the process cartridge B. After being moved into the sweeping range of the toner feeding member 21 by the developer conveying means 30, and further conveyed by the toner feeding member 21, the toner T is supplied to the photosensitive drum 8 by the development roller 5. Thus, image formation is continued without interruption. Next, as this toner T is consumed to a point at which substantially no toner remains within the sweeping range of the toner feeding member 21, a second toner remainder detection process is carried out. Figure 8 is a block diagram for the control executed after the toner absence is detected second time. As shown in Figure 8, when the toner absence is detected for the second time, this information is combined with the information stored as toner remainder detection history in the storing means 50, that is, "toner absence has been detected once," and a "no toner" warning message is displayed in the display section of the apparatus main assembly. Further, an arrangement may be made so that the image forming operation on the apparatus main assembly side can be temporarily prohibited if necessary. Even when the process cartridge B is transferred to another image formation apparatus before the second toner remainder detection, the toner absence warning can be reliably displayed by the main assembly of the second image formation apparatus A, since "toner absence has already been detected once" is recognized as cartridge specific information by the main assembly of the second image formation apparatus A. As described above, in this embodiment, the activation of the developer conveying means is linked to the results of the toner remainder detection by the toner remainder detecting means, making it possible to reliably convey the toner remainder in the toner storing portion, to the toner feeding member. Therefore, it is possible to prevent production of an image with white spots caused by lack of toner, without increasing the capacity of the driving source on the main assembly of the image formation apparatus A. Embodiment 2 The development apparatus 100 in this embodiment (Fig. 9) is a process cartridge constructed by integrally disposing a developer carrier member 5 like the aforementioned development roller, and a developing means 4 comprising a developer container portion containing developer (toner) to be supplied to the developer carrier member 5, in a plastic frame 2. In other words, the development apparatus 100 in this embodiment can be thought to be the process cartridge described in the first embodiment minus the photosensitive drum. Therefore, the structures and operations of the developer storing portion and the developer conveying means are the same as those described in the first embodiment. Thus, the components or sections which have the same structure or function as those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and their descriptions will be omitted. In the first and second embodiments, the toner remainder detecting means was described as a means employing a system which detects the toner absence by detecting the change in electrostatic capacity, but the same effects can be obtained by employing a different system in which the toner absence is detected by detecting the change in light transmission, developer weight, or torque needed by a toner stirring member. As is evident from the above descriptions, according to the preceding embodiments, as the developer in the developer storing portion decreases, the developer is moved without the need for increasing the capacity of the driving power source on the apparatus main assembly side. Therefore, it is possible to provide a process cartridge and a development apparatus, which do not need to be shaken, and are capable of preventing production of an image with white spots caused by lack of toner, and also to provide an image formation apparatus compatible with such a process cartridge or development apparatus. Thus, it is possible to improve operational efficiency in image formation, and to produce a high quality image. Further, according to the present invention, waste in toner consumption can be further reduced.

Claims: A process cartridge (B) detachably mountable to a main assembly (A) of an electrophotographic image-forming apparatus, comprising: an electrophotographic photosensitive member (8); developing means (4) for developing a latent image formed on said electrophotographic photosensitive member (8); a toner accommodating portion (1) for accommodating toner to be used by said developing means (4) to develop the latent image; a sensor (26) for generating a signal when detecting the decrease of a remaining amount of the toner accommodated in the toner accommodating portion (1); a first toner feeding member (21) for feeding the toner accommodated in the toner accommodating portion (1) from a sweeping range of the first toner feeding member (21) toward said developing means (4); and a second toner feeding member (30) for feeding the toner accommodated in the toner accommodating portion toward said first toner feeding member (21); wherein said second toner feeding member (30) starts to operate in response to the signal from said sensor (26), characterized in that : the second toner feeding member (30) is arranged for movement by a driving energy source contained in said process cartridge itself to move the toner into the sweeping range of the first toner feeding member (21). A process cartridge according to claim 1, wherein said second toner feeding member (30) is operated by elastic force of an elastic member. A process cartridge according to claim 2 wherein said elastic member comprises a coil spring or a compression spring. A process cartridge according to any of claims 1 to 3, wherein the second toner feeding means (30) is arranged for a single pivoting movement of a predetermined angle to move the toner into the sweeping range of the first toner feeding member (21). A process cartridge according to any preceding claim, wherein the movement of said second toner feeding member is prevented by a releaseable locking member (33) which is releaseable by a releasing member (32) provided in the main assembly in response to the detection of the decrease of the toner to permit feeding of the toner into the sweeping range of the first toner feeding member. A process cartridge according to any preceding claim, further comprising a storing element (50) for storing detection hysteresis of the remaining amount of the toner accommodated in said toner accommodating portion. A process cartridge according to any preceding claim, wherein the first toner feeding member is rotated in accordance with rotation of said electrophotographic photosensitive member. A process cartridge according to claim 7, wherein said electrophotographic photosensitive member is rotatable by a driving force received from the main assembly when the process cartridge is mounted to the main assembly, and said first toner feeding member is rotated by the said driving force. A process cartridge according to any preceding claim, further comprising a charging member (11) for charging said electrophotographic photosensitive member. A process cartridge according to any preceding claim, further comprising a cleaning member (10) for removing the toner remaining on the electrophotographic photosensitive member after transfer of the toner image to a recording member. A developing apparatus detachably mountable to a main assembly (A) of an electrophotographic image-forming apparatus for developing a latent image formed on an electrophotographic photosensitive member (8) of the electrophotographic image-forming apparatus, the developing apparatus comprising: a toner accommodating portion (1) for accommodating toner to be used by said developing means (4) to develop the latent image; a sensor (26) for generating a signal when detecting the decrease of a remaining amount of the toner accommodated in the toner accommodating portion (1); a first toner feeding member (21) for feeding the toner accommodated in the toner accommodating portion (1) from a sweeping range of the first toner feeding member (21) towards a developing means (4); and a second toner feeding member (30) for feeding the toner accommodated in the toner accommodating portion toward said first toner feeding member (21); wherein said second toner feeding member (30) starts to operate in response to the signal from said sensor (26), characterized in that : the second toner feeding member (30) is arranged for movement by a driving energy source (35) contained in said developing apparatus itself to move the toner into the sweeping range of the first toner feeding member (21). A developing apparatus according to claim 11, wherein said second toner feeding member (30) is operated by elastic force of an elastic member (35). A developing apparatus according to claim 12 wherein said elastic member (35) comprises a coil spring or a compression spring. A developing apparatus according to any of claims 11 to 13, wherein the second toner feeding means (30) is arranged for a single pivoting movement of a predetermined angle to move the toner into the sweeping range of the first toner feeding member (21). A developing apparatus according to any of claims 11 to 14, wherein the movement of said second toner feeding member is prevented by a releaseable locking member (33) which is releaseable by a releasing member (32) provided in the main assembly in response to the detection of the decrease of the toner to permit feeding of the toner into the sweeping range of the first toner feeding member. A developing apparatus according to any of claims 11 to 15, further comprising a storing element (50) for storing detection hysteresis of the remaining amount of the toner accommodated in said toner accommodating portion. A developing apparatus according to any of claims 11 to 16, wherein the first toner feeding member is rotatable in accordance with rotation of the electrophotographic photosensitive member of the image-forming apparatus, wherein the developing apparatus is mounted to the main assembly of the image-forming apparatus. A developer apparatus according to claim 17, wherein said first toner feeding member is rotatable by a driving force received from the main assembly when the developer apparatus is mounted to the main assembly. An electrophotographic image-forming apparatus for forming an image on a recording material, to which a process cartridge is detachably mountable, comprising: (a) a mounting portion for detachably mounting a process cartridge, said process cartridge including: an electrophotographic photosensitive member (8); developing means (4) for developing a latent image formed on said electrophotographic photosensitive member (8); a toner accommodating portion (1) for accommodating toner to be used by said developing means (4) to develop the latent image; a sensor (26) for generating a signal when detecting the decrease of a remaining amount of the toner accommodated in the toner accommodating portion (1); a first toner feeding member (21) for feeding the toner accommodated in the toner accommodating portion (1) from a sweeping range of the first toner feeding member (21) toward said developing means (4); and a second toner feeding member (30) for feeding the toner accommodated in the toner accommodating portion toward said first toner feeding member (21); wherein said second toner feeding member (30) is operable in response to the signal from said sensor (26); wherein the second toner feeding member (30) is arranged for movement by a driving energy source contained in said process cartridge itself to move the toner into the sweeping range of the first toner feeding member (21); and wherein the movement of said second toner feeding member is prevented by a releaseable locking member (33); (b) detecting means for detecting the remaining amount of the toner accommodated in said toner accommodating portion (1) of said process cartridge (B); (c) a releasing member (32) cooperable with the locking member (33) of the process cartridge to permit the operation of the second toner feeding member (30) in response to the detection of the decrease of remaining toner. An electrophotographic image-forming apparatus including an electrophotographic photosensitive member (8) for forming an image on a recording material, to which a developing apparatus is detachably mountable, comprising: (a) a mounting portion for detachably mounting a developing apparatus, said developing apparatus including: developing means (4) for developing a latent image formed on said electrophotographic photosensitive member (8); a toner accommodating portion (1) for accommodating toner to be used by said developing means (4) to develop the latent image; a sensor (26) for generating a signal when detecting the decrease of a remaining amount of the toner accommodated in the toner accommodating portion (1); a first toner feeding member (21) for feeding the toner accommodated in the toner accommodating portion (1) from a sweeping range of the first toner feeding member (21) toward said developing means (4); and a second toner feeding member (30) for feeding the toner accommodated in the toner accommodating portion toward said first toner feeding member (21); wherein said second toner feeding member (30) is operable in response to the signal from said sensor (26); wherein the second toner feeding member (30) is arranged for movement by a driving energy source contained in said developing apparatus itself to move the toner into the sweeping range of the first toner feeding member (21); and wherein the movement of said second toner feeding member is prevented by a releaseable locking member (33); (b) detecting means for detecting the remaining amount of the toner accommodated in said toner accommodating portion (1) of said developing apparatus; (c) a releasing member (32) cooperable with the locking member (33) of the developing apparatus to permit the operation of the second toner feeding member (30) in response to the detection of the decrease of remaining toner. An electrophotographic image-forming apparatus according to claim 19 or claim 20, wherein said releasing member (32) includes a solenoid actuated in response to an electrical signal produced in response to detection of a decrease in the remaining toner amount. An electrophotographic image-forming apparatus according to any of claims 19 to 21, further comprising a storing element (50) for storing detection hysteresis of the remaining amount of the toner accommodated in said toner accommodating portion (1). A method of refilling a toner accommodating portion (i) of a process cartridge according to any of claims 1 to 10 or a developing apparatus according to any of claims 11 to 18 wherein the second toner feeding means (30) has operated to move the toner into the sweeping range of the first toner feeding member (21), comprising the steps of: returning the second toner feeding means to its original position; and filling the toner accommodating portion (1) with toner. A method according to claim 23, wherein the step of returning the second toner feeding means (30) to its original position includes a step of engaging a locking member (33) to retain the second toner feeding means in its original position.

Inventors: IKEMOTO ISAO, SASAKI SHINICHI, IKEMOTO, ISAO, SASAKI, SHINICHI
Applicants: CANON KK, CANON KABUSHIKI KAISHA
Application year: 1997
Main classification: G03G21
IPC codes: G03G15, G03G21