JPH01250974A - Developing device and process cartridge - Google Patents

Abstract

PURPOSE:To reduce production cost by arranging rotating member so that its rotational axial line passes in the opening area of an opening part. CONSTITUTION:The rotational axial line of the rotating member 3e passes in the opening area of the opening part 94 for charging developer. Since the opening part 94 for charging developer is arranged so as to include, without evading, the rotational axial line of the rotating member 3e in its opening area, the effective area thereof is enlarged in comparison with an existing opening part. As a result, time required to charge developer in a developer container 3c is reduced, thereby increasing the production of process cartridges per unit time. The rationalization of production process is thus promoted, and the production cost can be thereby reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a developing device and a process cartridge for an image forming apparatus using electrophotographic technology, such as a copying machine or a laser beam printer.

(Prior Art) FIGS. 9 and 10 show a sectional view and a side view, respectively, of a conventional process cartridge 100 for an image forming apparatus.

The process cartridge 100 includes, in its sink 10, an electrophotographic photosensitive drum l as an image carrier, and a corona charger 2 as a charging device that uniformly charges the circumferential surface of the photosensitive drum l to a predetermined polarity. The process cartridge 100 includes four process devices, a developing device 3 and a cleaning device 4, and is attached to and removed from the main body of the image forming apparatus in the direction of the rotation axis of the photosensitive tram 1. .

Note that when such an image forming apparatus is installed in the process cartridge 100 at a predetermined position in the main body of the image forming apparatus, the mechanical drive system and electric circuit system on the image forming apparatus side or the mechanical drive system on the process cartridge 100 side are connected. It is designed to match and integrate with the drive system and electrical circuit system, respectively. In particular, the alignment between the photosensitive tram 1 in the process cartridge 100 and the optical system on the main body side of the image forming apparatus is made precisely.

The developing device 3 has a developing chamber 3b and a toner container 3c, a developing roller 3a is accommodated in the developing chamber 3b, and a toner t is stored in the toner container 3c. Toner container 3
A communicating hole 3d is provided at the bottom of C, and the toner t falls into the developing chamber 3b through the communicating hole 3d, and is placed on the developing roller 3a to participate in development. However, when the toner t is left standing for a long time, it has a tendency to aggregate and form a lump due to its own weight, and the communication hole 3d is blocked by the agglomerated toner t, resulting in a delay in replenishing the toner t. Normal developing action will no longer be obtained. To prevent this, use the stirring bar 9
It is set to 0. The stirring rod 90 is connected to the photosensitive tram 1 via a power transmission system (not shown), rotates around a shaft portion 90a in synchronization with the rotation of the photosensitive tram 1, and stirs the toner t. , thereby preventing agglomeration of toner t. In addition, one end of the stirring R590 (front side in Figure 9)
is a bearing part (not shown) provided on the side wall of the toner container 3c.
is supported by.

As seen in FIG. 10, an opening 91 for filling toner is provided in the side wall of the toner container 3c having the bearing, and this opening 91 is normally closed with a lid (not shown). It is being

The smaller the size of the opening 91, the longer the time required to fill the toner, which has a disadvantageous effect on production efficiency and production cost, especially when mass producing process cartridges 100 on an assembly line as described above.

(Problem to be solved by the invention) However, in the above conventional example, the opening 91 for filling the developer
must be bored while avoiding the shaft portion 90a of the stirring rod 90, and therefore its size must be relatively small. For this reason, it is difficult to shorten the time it takes to fill developer containers with developer, and due to this time loss, the number of process cartridges produced per unit time does not increase, which hinders the rationalization of the production process. There was also the disadvantage that it was difficult to keep costs low.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to make it possible to make the developer filling opening provided on one end surface of the developer container larger than that of the conventional one. An object of the present invention is to provide a developing device and a process cartridge.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a developer storage container having an opening for filling the developer and a rotating member for stirring and transporting the developer. The developing device is characterized in that the rotational axis of the rotating member passes through an opening area of the opening.

(Function) The developer filling opening according to the present invention is provided so as to include the rotational axis of the rotating member within the opening area without avoiding the rotational axis of the rotating member. The opening area can be made larger than conventional openings, which reduces the time required to fill the developer container with developer, increases the number of process cartridges produced per unit time, and streamlines the production process. This has also made it possible to lower production costs.

(Example) Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 11 is a longitudinal sectional view of a laser beam printer according to the present invention. In the laser beam printer, a large number of cut sheets P... are stacked on a paper feed tray 121, and each cut sheet P is fed It is transported to the image forming section by rollers 122 and transport rollers 123, and transferred to the transfer roller 12.
After the image is transferred by the printer 4, the sheet is guided to a fixing device 125 where it is fixed with a heat roller, and then discharged onto a paper discharge tray 127 outside the apparatus by a discharge roller 126.

By the way, the paper feed tray 121, the paper feed section including the paper feed roller 122, the transport section including the transport roller 123, and the fixing device 1
25, an ejection roller 126, and an ejection tray 1.
The paper discharge section including 27 is rotatably supported on the apparatus base B by a shaft A, and these sections are divided at the positions indicated by the dashed dotted lines in the figure and configured to be openable and closable.

Further, the image forming section constitutes a cartridge CG which integrates a photosensitive tram KD, a cleaning section C1, a secondary charging section T, and a developing section. The above-mentioned secondary phase electric device T charges the photosensitive drum KD by applying an electric bias to a semiconductive elastic body, for example, the conductive rubber roller 12B. The conductive rubber roller 128 is driven by the photosensitive tram KD and is in contact with the photosensitive tram KD under a pressure of several 100 g/cm 2 .

By the way, the cartridge CG is replaced with a new one after a certain amount of image formation, taking into consideration the life of the photosensitive tram KD, the life of the cleaning plate, and the lack of toner. It is done. That is, as shown in FIG. 12, when a part K of the exterior cover including the paper feeding, conveying, fixing, and paper ejection sections is opened, the cartridge CG can only be inserted and removed from the part K of the exterior cover that is opened. Therefore, the operator can take out the cartridge CG from the main body in a direction perpendicular to the drum generatrix direction.

Further, a new cartridge CG is installed in the main body by operating in the opposite manner to the above-mentioned removal process, and after installation, when the outer cover part K is closed, the cartridge CG is placed in a predetermined position under pressure from the transfer roller 124. It is securely set in position. Incidentally, when the exterior cover part K is opened, as shown in FIG. 12, the paper discharge tray 127 (see FIG. 11) is removed and the paper feed tray 121 is folded.

1 to 3 show an embodiment of a process cartridge 101 according to the present invention, FIG. 1 is a sectional view of the process cartridge 101, and FIG. 2 is a developing device included in the process cartridge 101. FIG. 3 is a sectional view taken along the line H--H of the toner container i3c in the developing device 3. FIG.

In the process cartridge 101 of this example, the photosensitive drum l as an image carrier is located in the cartridge housing (
It is located on the right side in Fig. 1 in (frame body) When stored, the drum cover 5 is hidden and protected as shown by the solid line in the closed state.

The left side of the photosensitive tram 1 is a photoimage exposure process section 19.
When the process cartridge 101 is installed in the image forming apparatus main body, the process cartridge 101 is inserted into the housing sink 10 almost horizontally from the image exposure device on the apparatus main body side through the slit-shaped exposure window 6 provided on the left side of the cartridge housing sink 10. It is irradiated by the incoming optical image exposure light.

The cleaning device 4 and the developing device 3 are arranged above and below a substantially horizontal optical image exposure optical path 17 extending from the exposure window 6 to the optical image exposure process section 19 of the photosensitive tram 1 across the optical path 17. It is.

Reference numeral 2A denotes a contact charging or friction charging roller as a charger that uniformly charges the circumferential surface of the photosensitive tram 1 to a predetermined polarity. It contacts the surface of the photosensitive drum 1 at a position upstream of the image exposure process section 19 in the photosensitive drum rotation direction (counterclockwise direction).

The cleaning plate 4a of the cleaning device 4 is in contact with the upper surface of the photosensitive tram l on the upstream side of the charging roller 2A in the rotational direction of the photosensitive drum.

The cleaning device 4 has a waste toner chamber 4d.

The developing roller 3a provided in the developing chamber 3b is in contact with or faces the lower surface of the photosensitive tram l on the downstream side of the photosensitive drum rotation direction from the photoimage exposure process section 19 with a predetermined small gap therebetween.

The cartridge 101 is installed into the image forming apparatus by opening the tram cover 5 about the support shaft 5a as shown by the two-dot chain line. Alternatively, during the process of installing the process cartridge 101 into the apparatus main body, the tram cover 5 is automatically opened by an opening/closing mechanism (not shown) on the apparatus main body side.

The developing device 3 includes a developing chamber 3b that accommodates a developing roller 3a;
The developing chamber 3b and the toner container 3c are connected to each other on the left side thereof, and the developing chamber 3b and the toner container 3c communicate with each other via a communication hole 3d provided in a partition wall between the developing chamber 3b and the toner container 3c. The toner t in the toner container 3c is agitated by the stirring rod 3e being rotated at a predetermined speed, and a portion of the stored toner t is agitated by the thin sheet member 3f provided at the radial end of the stirring rod 3e. The liquid is intermittently fed into the developing chamber 3b from the communication hole 3d every rotation of the stirring rod 3e.

Next, the operation of the process cartridge 101 having the above configuration will be explained.

First, when the process cartridge 101 is loaded into the main body of the image forming apparatus (not shown), the drum cover 5 is automatically rotated to the open position shown by the two-dot chain line, and the photosensitive tram 1 is exposed.

In this state, when a copying switch provided on the main body of the apparatus is pressed, a drive system (not shown) is operated, and the photosensitive tram 1, developing roller 3a, frictional charging roller 2A, and stirring rod 3e rotate in the directions of the arrows. The rotation of the stirring rod 3e stirs the toner t in the toner container 3c, and the toner t in the toner container 3c is conveyed to the developing chamber 3b via the communication hole 3d by the scooping sheet 3f, and is magnetically attached to the surface of the developing roller 3a.

On the other hand, the peripheral surface of the photosensitive tram 1 is uniformly charged to a predetermined polarity by a frictional charging roller 2A, and is irradiated with optical image exposure light by the action of an optical system (not shown) to form a latent image. Subsequently, the photosensitive tram 1 receives the toner t from the developing roller 3a, and converts the latent image into a developed image by selectively adhering the toner t. The image is transferred onto a sheet (not shown) that advances along the path from a sheet feeding mechanism (not shown). The paper is sent to a fixing device (not shown) and the toner image is fixed on the paper 1-, thereby completing the image formation. Incidentally, residual toner that remains in the photosensitive tram 1 and does not participate in development is scraped off by a cleaning plate 4a and collected in a waste toner chamber 4d.

Next, details of the developing device 3 according to the present invention will be explained.

FIG. 2 is a partial perspective view of the toner container 3C, which is a view of the toner container 3C viewed from the side having the opening 94. As shown in FIG. FIG. 3 is a sectional view taken along the line H--H in FIG. 2, and shows the direction in which the toner container cap 90 and the opening 94 are fitted together.

The bearing 3j is supported at the center of the opening 94 by four bearing ridges 3g arranged in a cross shape. That is, the opening 94 is divided into four fan-shaped openings 1194' by these four bearing ridges 3g. The shaft 3h of the stirring rod 3e is rotatably supported at its end within a bearing hole 3m provided in a bearing 3j.

A toner container cap 90 formed of a flexible material, such as vinyl chloride, has four fan-shaped openings 94.
'... four protrusions 90a, which are inserted and crimped into
It is formed with... Furthermore, in order to reliably fit the toner container cap 90 into the opening 94, two click protrusions 90b are provided on the circumferential surface of the stepped portion of the cap.

In the embodiment described in -1-, the number of bearing rifs 3g is four, or the number of bearing rifs may be less than four as long as it can securely support the bearing 3J.

Next, the operation of the first embodiment having the structure shown in "-" will be explained.

First, since the four bearing rifts 3g and the bearings 3j supported by these are provided, the shaft 3h of the stirring bar 3e can be pivotally supported at the center of the opening 94, and therefore the opening 9
4 does not need to be bored to avoid the bearing portion of the stirring rod 3e, and the opening 94 can be made large enough to occupy most of the side wall 3n of the toner container 3C. As a result, it becomes possible to fill the toner container 3C with the toner t in a short time.

Further, the toner container cap 90 has four protrusions 90a.
Since the toner t is inserted and pressed into the four openings 94' of the opening 94, the toner t is completely sealed in the toner containers 1 to 3C and will not spill out. At this time,
Since the wooden bearings 1 to 4 are in close contact with the rift 3g and the bearing 3j, the bearing rib 3g and the bearing 3j are firmly fixed, and the bearing 3J is accurately fixed. To make the rotation of the stirring rod 3e more stable.

Next, a second embodiment will be described based on FIGS. 4 and 5. In FIGS. 4 and 5, the same elements as those shown in the first embodiment are denoted by the same reference numerals, and their explanation will be omitted. FIG. 5 is a sectional view taken along the line I--I of the developing device 3 shown in FIG.

In the second embodiment, opening 94 is a circular opening. The toner container cap 91 has the same shape as that of the second embodiment, and has four protrusions 91a that are inserted into the opening 94 and press-fitted. These 4
The opposing surfaces 91a of the two projections 91a are formed to define a truncated conical space whose diameter increases as it moves leftward in FIG. This 4
The four projections 91a are inserted into a truncated conical space defined by the opposing surfaces 91a' of the four protrusions 91a.
A truncated conical bearing 31 formed to press against the opposing surfaces 91a of the two projections 91a is rotatably fitted loosely into one end of the shaft 3h of the stirring rod 3e. That is,
Since the bearing 31 is firmly fixed to the toner container cap 91, the shaft 3h is rotatable relative to the stationary bearing 31.

In the second embodiment, since the bearing 3g required in the first embodiment is not necessary, the opening area of the opening 94 is increased accordingly, and the toner filling time can be further shortened. Moreover, it has the advantage that the toner container 3C can be easily molded.

6 and 7 show the third embodiment, and in these figures, the same elements as those shown in the first or second embodiment are given the same reference numerals, and their explanations will be given below. is omitted. (Furthermore, FIG. 7 is a sectional view taken along the line J-J of the developing device 3 in FIG. A hypertrophic area of 3k has been formed. On the other hand, a bearing hole 92a is formed in the center of the toner container cap 92 and has a shape that can receive and stop the enlarged portion 3k. Here, the bearing hole 92
The inner diameter at the inlet of a is designed to be slightly smaller than the maximum diameter of the tapered enlarged portion 3, so that when the flexible toner container cap 92 closes the opening 94 of the toner container 3c, the bearing The entrance of the hole 92a is the stirring rod 3e.
The enlarged portion 3k of the shaft 3h expands the bearing hole 9.
2a gives a click feeling to the user and stops the enlarged portion 3h. Once inserted in this manner, the maximum diameter portion of the enlarged portion 3h is not hooked to the entrance of the bearing hole 92a, so that the toner container cap 92 is attached to the shaft 3 of the stirring rod 3e.
It will no longer be possible to drain it into a container. However, since the enlarged portion 3 is loosely fitted into the bearing hole 92a and the diameter of the bracket shaft 3h is designed to be slightly smaller than the inner diameter of the entrance of the bearing hole 92a, the shaft 3h is attached to the toner container cap. It is rotatable with respect to 92.

The advantage of this embodiment is that since the bearing and the toner container cap 92 are integrally formed, the number of parts can be reduced, and assembly work efficiency is improved, and the toner container cap 92 can be removed from the toner container 3c. <That's true. In the third embodiment, the enlarged portion 3 has a substantially conical shape, but by making it spherical, the click function can be maintained and the toner container cap 92 can be removed relatively easily. I can do it.

Next, the fourth embodiment will be explained based on FIG.

FIG. 8 is a sectional view of a process cartridge 102 showing a fourth embodiment of the present invention, and the same elements as those shown in FIG.

The stirring rod 30 is formed with three wooden legs 30a, each of which forms an angle of 120° with respect to each other.
A scoop sheet member 3f... is attached to each.

Further, the non-driven end (front side in FIG. 8) of the stirring rod 30 is a free end that is not supported by a shaft.

Therefore, although the stirring rod 30 is supported only at the other end, that is, the drive side end, it can stand on its own because it has three legs 30a, and the shaft 3h is always located at the center of the toner container 3c. is maintained.

The advantage of this embodiment is that the non-driving end of the shaft 3h of the stirring rod 30 is made a free end, thereby eliminating the need for a bearing. Also, the opening is similar to all other embodiments, and the toner container 3
It can be formed so as to occupy almost the entire side wall of C.

(Effects of the Invention) As described in 2 below, according to the present invention, the axis of rotation of the rotating member passes through the opening area of the opening, so the opening for filling toner is arranged to avoid the axis of rotation of the rotating member. Therefore, the opening can be made large enough to occupy substantially the entire side wall of the toner container. As a result, the time required to fill toner is greatly shortened, improving process cartridge production efficiency.
It has also become possible to keep production costs low.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a process cartridge according to the present invention;
FIG. 2 is a partial perspective view of the developing device according to the first embodiment, and FIG.
The figure is a sectional view taken along the line H--H of the developing device shown in FIG. 2, FIG. 4 is a partial perspective view of the developing device according to the second embodiment, and FIG. 5 is a sectional view taken along the line ■-■ of the developing device shown in FIG. 4. , FIG. 6 is a partial perspective view of the developing device according to the third embodiment, FIG. 7 is a sectional view taken along line J-J of the developing device of FIG. 6, and FIG. 8 is a sectional view of the process cartridge of the fourth embodiment. 9 is a sectional view of the conventional process car 1 to ridge, FIG. 10 is a side view of the process car L-ridge of FIG. 9, and FIG. 11 is a longitudinal sectional view of the laser beam printer according to the present invention. FIG. 12 is a longitudinal sectional view showing the laser beam printer in an open state. 3...Developer, 3C...Toner container (developer storage container), 3e, 30...Stirring bar (rotating member), 94...
・Opening, t...1~ner (developer), 100°10
1.102...Process cartridge. Patent applicant: Canon Co., Ltd. agent Patent attorney Ryo Yamashita −

Claims (3)

[Claims] (1) In a developing device including a developer storage container having an opening for filling the developer and a rotating member for stirring and transporting the developer, the axis of rotation of the rotating member is aligned with the opening of the opening. A developing device characterized by passing through an opening area. (2) The developing device according to claim 1, wherein the developer storage container has a substantially cylindrical shape, and the axis of rotation passes through substantially the center of the opening area. (3) A process cartridge including the developing device.