JPS6299764A - Developing member shutter opening and closing mechanism for developing device - Google Patents

Abstract

PURPOSE:To obtain the reliable shutter opening and closing mechanism of automatic opening and closing system by providing an elastic member that interferes elastically with a part of a developing member shutter in the direction of opening the developing member shutter of a developing device side when the developing device is mounted and operated, and in the direction of closing when the device is operated for detaching. CONSTITUTION:When the developing device B is lowered between the front and rear side plates 1, 1 of a cartridge frame, claw parts 17, 17 at both ends of upper side of a shutter plate 14 are abutted with the upper faces of elastic sheet pieces 23, 23 of the cartridge frame side and become the state of stopping. The shutter plate 14 becomes open state relatively to a developing sleeve 12, and pin shafts 16, 16 at both ends of upper side of the shutter plate are positioned respectively at upper ends of guide long holes 20, 20. The tips of elastic sheets 23, 23 warp downward while resisting elasticity, and claw parts 17, 17 drops into a space between an L-shaped edge 21 of cartridge frame side and a longitudinal side 21b, and the state of opening of the shutter plate 14 is maintained stably thereafter.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention [Field of Industrial Application] The present invention relates to a developing device in an image forming apparatus such as an electrophotographic type, an electrostatic recording type, or a magnetic recording type. More specifically, the present invention relates to a developing member shutter opening/closing mechanism of a developing device.

[Conventional technology]

In general, the developing device of an image forming apparatus (hereinafter referred to as this machine) is subject to maintenance, inspection, repair, and replacement with another developing device (for example, to change the developed color, the developing device contains a developer of the desired color). In order to facilitate the replacement of the cartridge, etc., it is configured to be removable from the machine or from a so-called process cartridge that is inserted into and removed from the machine.

Generally, in the above-mentioned removable developing device, the externally exposed surface of the developing member (developing sleeve, developing roller, etc.) of the developing section is hidden when it is removed from the machine or the process cartridge. A shutter member is provided to protect the member and prevent the developer from scattering to the outside.

The shutter mechanism operates the shutter member in the opening direction against a positive biasing member in the closing direction or against the closing force of its own weight in conjunction with the mounting operation of the developing device on the machine or the process cartridge. On the other hand, an automatic type in which the shutter member is moved in the closing direction by a member that actively urges the shutter member in the closing direction in conjunction with the removal operation, or by its own gravity, and it is closed when the developing device is removed and opened when it is installed. There are manual opening/closing types that can be operated.

[Problem that the invention seeks to solve]

However, as image forming apparatuses - process cartridges, developing devices, etc. - become as miniaturized as possible, the above-mentioned shutter mechanism installed in the developing section has become more and more important. In many cases, it is impossible to adopt an automatic shutter mechanism as described above due to lack of installation space or the weight of the shutter member, and manual opening/closing is cumbersome and requires a developing device. It's easy to forget to close the shutter when you take it out or open it when you put it on, so it lacks reliability.

The present invention has been proposed in view of the above, and is an automatic opening/closing type that can be adopted without problems even in a developing device that is as small as possible, and has reliability in that the shutter member is always opened and closed reliably. The purpose of the present invention is to provide a practical shutter opening/closing mechanism with a simple configuration.

Summary: Structure of the Invention [Means for Solving the Problems] The present invention provides an image forming apparatus or a developing device that can be attached to and detached from a process cartridge that can be freely inserted and detached from the image forming apparatus according to a guide. When the developing member shutter on the developing device side is operated, the developing member shutter on the developing device side is opened, and when it is removed, the developing member shutter is moved in the opposite direction, so that the member that elastically interferes with a part of the developing member shutter is moved to the image forming device. This is a developing member shutter opening/closing mechanism of the developing device, which is disposed on the machine or the process cartridge side.

[For production]

With a simple configuration just arranging the elastic member as above,
If a part of the developing member shutter on the developing device side interferes with the elastic member during the process of attaching and detaching the developing device to the main image forming apparatus or the process cartridge, the opening/closing movement of the shutter member may occur in conjunction with the operation. automatically and reliably.

〔Example〕

In FIG. 1, A indicates a process cartridge (drum unit) inserted into and removed from an image forming apparatus (not shown), and B indicates front and rear side plates 1 and 1 of the cartridge frame (housing).
A developing device is detachable between the two.

A photosensitive drum D as an image carrier is rotatably built into the frame of the cartridge A, and process equipment such as a charger and a drum cleaner are also built in according to design specifications.

FIG. 2 is a sectional view of the cartridge A with the developing device B attached thereto. To attach the developing device B to the cartridge A, hang the developing device B using a hanging handle 4 that is freely rotatable about shafts 3 and 3 between the front and rear side plates 2 of the developing device B (see 2 in Fig. 8). The dotted chain line indicates the angular attitude of the developing device B with respect to the handle 4 when it is held in a suspended state), and the developing device B
The support shafts 5 provided at the bottom of the front and rear side plates 2φ2, respectively, projecting outward, are fitted into guide grooves 6-6 formed on the inner surfaces of the front and rear side plates 1, 1 of the cartridge frame, respectively.・
Grate it in 1 hour. In conjunction with this lowering operation, the developing member shutter plate 14 of the developing device B, which is in the closed state, automatically opens (FIG. 5 is an intermediate state diagram). This will be discussed later. Finally, as shown in the second figure, the supporting shafts 5, 5 on the side of the developing device B are received by the lower ends of the guide grooves 6, 6, respectively, and are also extended outwardly by the vertical rods on the front and rear sides of the hanging handle 4, respectively. The protruding support shafts 7, 7 are received in the middle of the guide grooves 6, 6 in correspondence with the four parts 8, 8, and the developing device B
is stably mounted in a predetermined attitude facing the photosensitive drum D within the cartridge frame.

To remove the developing device B in the above-mentioned installed state, grasp the hanging handle 4 and move the handle 4 so that the supporting shafts 7 and 7 of the handle are supported by the recess 8.
- Rotate the developing device a little around shaft 3 until it escapes from 8! This is done by pulling up tB from between the front and rear side plates 1 and 1 of the cartridge frame along the guide grooves 6 and 6. In conjunction with this lifting operation, the developing member shutter plate 14 of the developing device B, which is in the open state, is automatically closed. This will be discussed later.

In the developing device B, reference numeral 10 denotes a housing housing for storing the developer T, which has approximately the same length as the photosensitive drum D and is long in the front-back direction. The top surface of the casing is a lid plate 11 that can be opened and closed, and the developer T is introduced into the casing 10 by opening the lid. Reference numeral 12 denotes a developing sleeve as a developing member, and approximately the right half circumferential surface thereof is inserted into the housing 10 at the lower part of the left side wall plate of the housing facing the photosensitive drum D side, and the approximately left half circumferential surface is exposed to the outside of the housing. It is horizontally installed with both front and rear ends rotatably supported by front and rear side plates of the housing 10. 13 is the housing 10
This is a rotating member for stirring the developer disposed inside.

Reference numeral 14 denotes an oblong shirt plate having a width and length that can cover and hide substantially the left half circumferential surface of the developing sleeve 12, that is, the outer exposed surface of the sleeve. Pin shafts 15, 15, 16, and 16 are formed at both ends of the lower longitudinal side and at both ends of the upper longitudinal side of the shirt shirt plate, projecting in the extending direction of the lower longitudinal side and the upper longitudinal side, respectively. In addition, the above-mentioned pin shafts 16 are provided at both ends of the upper longitudinal side.
・Separately from 16, a claw portion 17 is made to protrude in the direction in which the upper longitudinal side extends.
・It forms 17.

18Φ18 is a pair of rotary levers whose bases are disposed on both ends of the developing sleeve 12 so as to be freely rotatable about the axis of the sleeve, and a small hole is formed at the tip of each of the levers. The pin shafts 15, 15 on both ends of the longitudinal lower side of the shirt shirt plate are fitted into the small holes so as to be rotatable, thereby connecting the lower side of the shirt shirt plate and the levers 18, 18.

Reference numerals 19 and 19 designate a pair of longitudinally extending plates provided on the front and rear side plates 2 and 2 of the developing device housing 10 so as to protrude in the direction of the drum D, respectively, and each longitudinally extending guide hole 2 is formed in the surface of each of these protruding plates.
0 and 20 are formed, and by fitting the pin shafts 16 and 16 at both ends of the longitudinal upper side of the shirt flap plate 14 into the long holes 20 and 20, respectively, the upper side of the shirt flap plate 14 and the both overhanging plates 19 are inserted.・It is connected with 19.

Therefore, the shutter plate 14 is moved downward, that is, on the substantially left half circumferential surface side, which is the outwardly exposed surface of the developing sleeve 12, by the rotation of the levers 18, 18 and the guidance of the elongated holes 20, 20. It can be opened and closed freely.

Reference numeral 21 designates the edge of the upper plate of the process cartridge frame on the side where the developing device is disposed, and is an abbreviated step-sewn edge. 22・22
The block pieces 22 and 2 are integrally formed on the inner surfaces of the front and rear side plates 1 and 1 of the cartridge frame body in close proximity to both the front and rear ends of the above-mentioned shaped edges.
The upper surface of 2 is positioned 1σ higher than the upper surface of the horizontal side 2La of the above-mentioned forming edge 21. 23-23 is a comparative multilayered polyethylene terephthalate sheet piece (having spring elasticity) as an elastic member whose tip end protrudes in the direction of the L-shaped edge 21 on the upper surface of each of the block pieces 22, 22, and is fixed with the bins 24, 24. The claw portion 17 of the shirt shirt plate 14 is attached to the elastic sheet pieces 23, 23, which are mylar sheet pieces).
-17 have a corresponding relational structure.

(1) Opening operation of the shutter plate 14 As mentioned above, the developing device B is suspended by the hanging handle 4 and is lowered between the front and rear side plates 1 and 1 of the cartridge frame. It is in a closed state with respect to the sleeve 12. When the developing device is lowered to a certain extent, the claws 1 on both ends of the upper side of the shutter plate 14
7 and 17 come into contact with the upper surfaces of the elastic sheet pieces 23 and 23 on the cartridge frame side, respectively, and are in a receiving state (FIGS. 3, 4(a), and 5).

As a result, from then on, the shirt shirt plate 14 is replaced by the elastic sheet piece 2.
3 and 23, but as the main body of the developing device B continues to descend, the shutter plate 14 becomes open relative to the developing sleeve 12.

Then, the main body of the developing device B is lowered, and as the device B is moved in a direction in which it approaches the photosensitive drum D by the oil passages of the guide grooves 6 to a predetermined position and directly faces the photosensitive drum D, the claw portions 17 and 17 of the shutter plate 14 are moved. 17 moves in the direction of the tip of the elastic sheet pieces 23, 23 receiving it (see Fig. 4).
b)・(C)).

Then, just before the supporting shafts 5 and 5 of the developing device reach the lowest ends of the guide grooves 6, the bottle shafts 1 at both ends of the upper side of the shutter plate are moved.
6-16 are positioned and received at the upper ends of the guide elongated holes 20-20, respectively, and the opening of the shirt shirt plate 14 becomes maximum, so that the claw portions 17- The downward force of the main body of the developing device B acts directly and strongly through 17.

As a result, the tips of the elastic sheet pieces 23, 23 bend downward against the elasticity (FIG. 4(d)), and the claws 17, 17 are connected to the block pieces 22, 2 to which the elastic sheet pieces 23, 23 are attached.
2 and the vertical side 21b of the L-shaped edge 21 on the cartridge frame side.
The front bent edge 14a of the upper longitudinal side of the shutter platework 4 including the claws 17, 17.
is received on the upper surface of the horizontal side 21a of the L-shaped edge 21, and the opened state of the shirt shirt plate 14 is stably maintained thereafter. The claw portions 17, 17 and the elastic sheet piece 23 with cut edges.
The tip of 23 returns to its original bulging state due to its own elasticity (FIG. 4(e)).

Immediately after that, the supporting shafts 5, 5 of the developing device B reach the lower ends of the guide grooves 6, 6 and are received, and the supporting shafts 711 on the side of the hanging handle 4
The receiver 7 located in the middle of the guide groove 6-6 is received in correspondence with the four parts 8 and 8, and the developing device B is in the shutter plate open state and is facing the photosensitive drum D in the cartridge frame in a predetermined direction. It is stably attached in the posture state (Fig. 2).

Note that when the developing device B is attached to the process cartridge A as described above, the drum gear G integrated with the drum D
1 (FIG. 1), the developing sleeve gear G2 on the side of the developing device B is in mesh. When the process cartridge A is installed in the image forming apparatus (not shown), the drum gear G
1 is in mesh with the drive gear on the machine side, and the drive gear rotates the drum D/developing sleeve 1z, and the rotation of the developing sleeve gear G2 is transferred to a reduction gear train (not shown).
is transmitted to the rotating shaft of the developer agitating member 13, and the member 13 is rotated. Also, the electrical coupling members (not shown) on the machine side and the cartridge side are connected to each other, and the power supply on the machine side energizes the built-in charging devices on the cartridge A side and applies a developing bias to the developing sleeve 12. It becomes possible to apply electricity such as application.

(2) Closing operation of the shirt cover plate 14 Grasp the handle 4 of the developing device B of the process cartridge A that has been removed from the image forming apparatus, and hold the handle 4 in the recess 8. Axis 3 until it escapes from 8.
3 and pull it up from between the front and rear side plates 1 and 1 of the cartridge frame.

During the lifting operation process, the claw portion 17 of the shirt top plate 14
17 moves between the north surface of the horizontal edge 21a of the L-shaped edge 21a and the elastic sheet piece in the space between the block piece 22 into which the claws 17-17 are depressed and the vertical edge 21b of the L-shaped edge 21. 2
Since the shutter plate 14 is restricted in a narrow range between the tip and the lower surface (wing surface) of the tip 3 (FIG. 4(e)), the movement of the shutter plate 14 is restricted, while the main body of the developing device B is pulled upward. As the development progresses, the shutter plate 14 becomes closed relative to the developing sleeve 12 (FIG. 6).

As the main body of the developing device 21B continues to be pulled up, the pin shafts 16, 16 at both ends of the upper side of the shutter plate move into the guide elongated holes 20, 16, respectively.
When the lower end of the sheet material 20 is reached and received and the shirt flap plate 14 is completely closed, the developing device B
The lifting force of the main body acts strongly directly.

As a result, the tips of the elastic sheet pieces 23, 23 bend upward against the elasticity (FIG. 4(f)), and this bending causes the claws 17, 17 of the shirt flap plate 14 to
23 (Fig. 4(g)), and the edge with the elastic sheet piece is cut.

That is, the developing device B includes the front and rear side plates 1 and 1 of the cartridge frame.
The shutter plate 14 automatically closes with respect to the developing sleeve 12 in conjunction with the lifting operation from the gap, and finally the shutter plate 14 is always reliably taken out in a completely closed state.

Figures 7 and 8 are a cross-sectional view and a side view of the developing device B with the shutter plate 14 in the closed state, which is placed on a horizontal surface 30 such as a desk surface.C. More than the effects of the invention As described above, the present invention is designed to prevent problems such as problems in which the optimum fulcrum position of the shutter member and space for the biasing member cannot be secured due to the miniaturization of developing devices, etc., and the weight of the shutter member (its own weight). This is a simple and practical shutter opening/closing mechanism that is reliable, automatically opens/closes, always opens and closes the shutter member reliably, and does not pose a problem even in cases where it is impossible to generate sufficient force (force). .

[Brief Description of the Drawings] Figure 1 is a perspective view of a process cartridge and a developing device attached to and detached from it, Figure 2 is a sectional view of the developing device attached to the process cartridge, and Figure 3 is an elastic 4(a) to 4(e) are partially enlarged plan views showing the state in which the claw portion of the shirt cover is in contact with and received on the sheet piece.
Figure 5 is a diagram of the state change of the elastic sheet piece and the claw part during the process of installing the developing device, Figures (f) and (g) are the same diagrams showing the process of removing the developing unit, which is the opposite of the above, and Figure 5 is the process during installation. FIG. 6 is a cross-sectional view of the developing device in the middle of being taken out, and FIGS. 7 and 8 are cross-sectional views and side views of the taken-out developing device placed on a horizontal surface such as a desk surface. A is a process cartridge, B is a developing device, 12 is a developing sleeve, 14 is a shutter plate, and D is a photosensitive drum. Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] (1) When the image forming apparatus or the developing device, which is attached to and removed from the image forming apparatus or the process cartridge that can be freely inserted into and removed from the image forming apparatus, is operated along the guide, the developing member shutter on the developing device side is opened. , a developing member shutter of the developing device, wherein an elastic member is disposed on the main unit of the image forming apparatus or on the process cartridge side, the elastic member elastically interfering with a part of the developing member shutter in the reverse closing direction when the ejecting operation is performed; Opening/closing mechanism.