JP2537665B2 - Image forming device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to an image forming apparatus, and more particularly, in an image forming apparatus such as an electrophotographic copying apparatus, a laser beam printer, a printing machine, or a facsimile, two or more developing devices. The present invention relates to a color image forming apparatus equipped with.

2. Description of the Related Art As demand for color image forming apparatuses has increased sharply as in recent years, downsizing and cost reduction of the color image forming apparatuses have been achieved, and a compact and low cost color image forming apparatus has been developed. It came to be commercialized. In such a color image forming apparatus that is downsized and reduced in cost, a developing device in which developers of different colors are contained in a limited space around the image carrier is provided. Since a plurality of the developing devices are provided, it is necessary to downsize each developing device. Therefore, for example, when high-speed recording is required, in consideration of the situation that the developer consumption amount per unit time increases, the developing device is developed in an empty space near the developing device in the image forming apparatus. An image forming apparatus has been proposed in which a hopper for supplying the agent is provided. To further explain the proposal, a shutter mechanism is interposed in a connecting portion that communicates between the developing device and the hopper, and in the shutter mechanism, the developing device is formed on the image carrier. The connection portion is opened when the electrostatic latent image is in the state of being close to the image carrier to make it visible, and the connection portion is opened when the developing device is separated from the image carrier and when the developer is supplied to the hopper itself. Is designed to close.

FIGS. 3, 4, and 5 show a developing device and a hopper included in the image forming apparatus according to the above proposal. That is, in FIG. 3, FIG. 4, and FIG. 5, in the peripheral portion of the image bearing member, that is, the photosensitive drum 2, which is rotatably supported in the clockwise direction in FIG. A developing device 4 is disposed on the upstream side, and a developing device 3 is disposed on the downstream side of the developing device 4 in the rotation direction of the photoconductor drum 2 in proximity to the developing device 4. (That is, the developing device 4 is provided above the developing device 3.) In the space portion above the developing device 4 in the image forming apparatus main body 1 and above the developing device 3, the developing device is provided. A hopper 5 for supplying the developer T to the developing device 3 is provided adjacent to the developing device 3 and the developing device 4. The above-mentioned configuration will be described in more detail below.
The developing device 3 as a whole is configured to be reciprocally movable in the left-right direction in FIGS. 3, 4, and 5, and a developing device housing 3d having an opening formed in a portion facing the photoconductor drum 2 is shown.
And a developing sleeve 3a that is rotatably supported by the opening of the developing device housing 3d, and the black developer T, which is frequently used, is stored in the developing device housing 3d. At the top of the developer housing 3d, the developer receiving port 3b
And an operating member 3c for opening and closing the shutter 20, which will be described later. Like the developing device 3 described above, the developing device 4 is also configured to be reciprocally movable in the left-right direction as a whole as shown in FIGS. 3, 4, and 5, and has an opening at a portion facing the photoconductor drum 2. It has a developing device housing 4d (not shown) and a developing sleeve (not shown) rotatably supported at the opening of the developing device housing 4d. A color developer that is used less frequently is stored. A hopper such as the hopper 5 for supplying the developer T to the developing device 3 is not provided near the developing device 4, and the developing device 4 allows the color developer to be supplied to the developing device 4. For developing device 4
When the developing device 4 is separated from the photoconductor drum 2, the developing device 4 can be easily detached from the device body 1 by pulling out the developing device 4 from the device body 1 to the front side. As apparent from FIGS. 4 and 5, the hopper 5 has a rectangular box shape as a whole, and the developing device 3 is provided on the lower surface thereof.
A developer replenishment port for replenishing the developer, that is, a developer discharge port 5a of the hopper 5 is formed, and a rotation shaft 5b is planted on the upper surface and the lower surface of the image forming apparatus main body 1. It is attached rotatably. A conveyance screw 18 is provided inside the popper 5, and the conveyance screw 18 is driven by a motor 19 attached to the outside of the hopper 5 to convey the developer T toward the developer discharge port 5a. It is like this. The hopper 5 is arranged at a position that does not adversely affect the movement of the developing device 4 in the left-right direction of FIGS. 3, 4, and 5 and the attachment and detachment of the developing device 4 from the apparatus main body 1. Shall be set. Developer 3
And within the slight void defined by the hopper 5,
The shutter 20 is rotatably attached to the lower surface of the hopper 5 by a rotary shaft 21. Shutter 20
Is a plate-like member having a substantially triangular shape as a whole. The shutter 20 has a projection 20a formed at one end thereof, and the developer discharge port 5a of the hopper 5 and the developing device 3 are A hole 20b communicating with the developer receiving port 3b and allowing the developer to pass from the inside of the hopper 5 to the developing device 3 is formed. The projection 20a of the shutter 20 is provided with a fourth shutter 20a.
By urging the shutter 20 in the direction of arrow A,
In order to forcibly position the developer discharge port 5a to the position where it is always closed (the position shown by the broken line in FIG. 6), one end is connected to the other end of the spring 22 attached to the lower surface of the hopper 5. There is. The lower surface of the hopper 5 is engaged with the projection 20a of the shutter 20,
A stopper 20d for restricting the rotation of the shutter 20 is attached.

In the structure as described above, as shown in FIG. 6, the developing device 3 is located at the position closest to the photosensitive drum 2 from the position farthest away from the photosensitive drum 2 (that is, formed on the photosensitive drum 2). When the electrostatic latent image is moved to a position for developing the electrostatic latent image), the operating member 3C provided on the upper portion of the developing device 3 engages with the side surface portion 20C of the shutter 20, and the shutter 20 6 is rotated counterclockwise in FIG. 6 against the biasing force of the spring 22. By rotating the shutter 20 as described above, the developer discharge port 5 of the hopper 5
a, the developer receiving port 3b of the developing device housing 3d and the shutter 2
The 0 holes 20b communicate with each other in an aligned state (the state shown by the solid line in FIG. 6). In this state, when the remaining amount of the developer T accommodated in the developing device 3 decreases, a well-known developer remaining amount detection sensor (not shown) operates,
A signal indicating that the developer T needs to be supplied is output. When the above signal is output from the developer remaining amount detection sensor (not shown) and given to the control circuit (not shown),
The motor 19 starts rotating based on a drive command signal output from a control circuit (not shown), and drives the conveying screw 18. By driving the transport screw 18, the developer T contained in the hopper 5 is discharged from the developer discharge port 5a.
20b, passing through the developer receiving port 3b, falling freely, and developing device 3
The developer T is replenished to the developing device 3 in an amount substantially the same as the amount of developer consumed in.

When the developing device 3 moves from the position closest to the photoconductor drum 2 to the position farthest from the photoconductor drum 2, the engagement between the operating member 3C and the side surface portion 20c of the shutter 20 is released, and the shutter is released. 20 is rotated in the direction of arrow A in FIG. 6 by the urging force of the spring 22. The rotation of the shutter 20 in the direction of arrow A in FIG. 6 due to the urging force of the spring 22 is stopped by the protrusion 20a of the shutter 20 engaging with the stopper 20d described above. Sixth
Each part shown by the dotted line shows a state in which the shutter 20 is stopped from rotating in the arrow A direction in FIG. 6 by the engagement of the protrusion 20a with the stopper 20d. Is the position of the developer discharge port 5a and the developer receiving port 3b.
However, the developer discharge port 5a is closed by the shutter 20, and the developer receiving port
The shutter 20 shields the developer discharge port 5a from the shutter 3b.

Here, when the developer T is replenished to the hopper 5 itself from the outside, the hopper 5 itself can be removed from the image forming apparatus main body 1, but the hopper 5 can be moved around the rotating shaft 5b to a fourth position. It is also possible to rotate in the direction of arrow B in the drawing and replenish the developer T from the upper portion of the hopper 5.
In any of the above cases, the cutter 20 rotates in the direction of arrow A by the urging force of the spring 22 to close the developer discharge port 5a, as described above. When the developing device 4 is detached from the apparatus main body 1, the developing device 4 is rotated in the same manner as when the developer T is replenished to the hopper 5 from the outside, and the developing device 4 is rotated by the arrow C in FIG. Pull out in the direction of. Even when the developing device 4 is mounted on the apparatus main body 1, it is premised that the hopper 5 is first rotated, but after the mounting of the developing device 4 on the apparatus main body 1 is completed, the hopper 5 is returned to a predetermined position. As a result, the developing device 4 is mounted at a predetermined position in the apparatus body 1, and the image forming operation of the apparatus body 1 becomes possible. The hopper 5 has a mechanism that returns to a predetermined position by fixing a front cover (not shown) of the apparatus main body to a predetermined position by a known method.

Problems to be Solved by the Invention The hopper 5 having the above-described configuration has greatly contributed to the miniaturization and cost reduction of the color image forming apparatus. However, in the image forming apparatus having the above-described configuration, when the hopper 5 rotates in the direction of arrow B in FIG. 4, the shutter 20 gradually covers the developer discharge port 5a of the hopper 5, and , The position of the developer discharge port 5a and the developer receiving port 3b as the hopper 5 rotates in the direction of arrow B in FIG.
The position of was gradually shifting. Therefore, when the hopper 5 rotates in the direction of arrow B in FIG. 4, part of the developer T dropped from the developer discharge port 5a is scattered outside the developer receiving port 3b. ,
As a result, the inside of the image forming apparatus body 1 is contaminated and the apparatus body 1
There are problems that the device itself malfunctions, the document and the transfer material are contaminated, and even the operator's hands and clothes are contaminated.

Therefore, the present invention was devised in order to solve the above-mentioned problems, and an object of the present invention is that the developer, which is replenished from the hopper to the developing device when the hopper is rotated, is supplied from the hopper to the image forming apparatus main body. An image that does not cause malfunction of the device itself, contaminate the manuscript or transfer material, or even contaminate the operator's hands or clothes by preventing the particles from scattering inside. A forming device is provided.

Means for Solving the Problems The above object is achieved by the image forming apparatus according to the present invention. In summary, the present invention relates to an image bearing member carrying a latent image, and a developing device having a developing position adjacent to the image bearing member and a developer receiving port movable between a separating position spaced from the image bearing member. And a hopper having a developer replenishing port for replenishing the developer to the developing device, the hopper being movable between a replenishing position for replenishing toner by an operator and a storing position housed in the main body. In the above, the hopper moves integrally with the developing device, and the hopper rotates about the developer supply port,
The image forming apparatus is characterized in that the developer receiving port and the developer replenishing port are aligned regardless of the movement of the developing device and the hopper.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows a color image forming apparatus capable of color development of two colors according to an embodiment of the present invention. Third
The configuration of the color image forming apparatus shown in the drawing is already known, but the outline thereof is as follows.
That is, in FIG. 3, the photoconductor drum 2 is disposed in a substantially central portion of the image forming apparatus main body 1. The photosensitive drum 2 is rotatably supported in the direction of arrow X (clockwise direction) in FIG. 3, and the peripheral portion of the photosensitive drum 2 is
Various devices necessary for executing the image forming sequence together with the photosensitive drum 2 include a cleaning device 16, a primary charging device 6, a developing device or developing device 4, a developing device or developing device 3, and a registration roller pair. 10, a transfer charger 11, a separation charger 17, and a transfer material conveying path 12 are arranged in this order from the upstream side to the downstream side in the rotation direction of the photosensitive drum 2. On the upstream side of the above-mentioned registration roller pair 10 in the apparatus main body 1 in the transfer material conveying direction (that is, on the right side of the apparatus main body 1), there are provided a transfer material overlap feed prevention roller pair 15 and a paper feeding roller 9, A paper feed cassette 8 is provided in the vicinity of the paper roller 9 so as to be detachable from the apparatus main body 1. Paper discharge rollers 14 are provided on the downstream side of the transfer material transport path 12 in the apparatus body 1 in the transport direction, in contact with the fixing device 13 and the left side of the apparatus body 1. At the position of the side surface portion of the developing device 4 above the developing device 3 in the apparatus main body 1, the developing device 3 and the developing device 4 are in close proximity to each other and movement of the developing device 4 (details will be described later) is hindered. To prevent this, a developer replenishing means, that is, a hopper 5 is provided.

The above configuration will be described in more detail below. The cleaning device 16 scrapes and collects a developer such as a one-component magnetic toner remaining on the photosensitive drum 2. The primary charger 6 charges the outer peripheral surface of the photosensitive drum 2 substantially uniformly. The image exposure unit (not shown) exposes the outer peripheral surface of the photoconductor drum 2 which is charged substantially uniformly by the primary charger 6 to the image exposure unit 7.
By irradiating with, the electrostatic latent image corresponding to the document image information is formed on the outer peripheral surface of the photosensitive drum 2. As shown in FIG. 3, each of the developing device 3 and the developing device 4 is configured to be reciprocally movable in the direction of the arrow in FIG. 3, and when the developing device 3 and the developing device 4 move toward the photosensitive drum 2, the respective developing sleeves are moved. The electrostatic latent image formed on the photosensitive drum 2 is visualized by the developing bias voltage applied to 3a and 4a. In the present embodiment, the developing device 4 contains a color developer that is not frequently used, and the developing device 3 contains a black developer that is frequently used. The details of the configurations of the developing device 3 and the developing device 4 are as already described with reference to FIGS. The transfer charger 11 is exposed to the transfer material P supplied from the paper feed cassette 8 via the paper feed roller 9 and the transfer material overlap feed prevention roller pair 15 and supplied at a predetermined timing by the registration roller pair 10. The visible image formed on the body drum 2 is transferred. Separating charger 17
Is configured to separate the transfer material P adsorbed on the photoconductor drum 2 during the transfer step from the photoconductor drum 2. The fixing device 13 receives the transfer material P on which the visible image is transferred, which is given through the transfer material conveying path 12, and fixes the image. The paper discharge roller 14 receives the transfer material P on which the image is fixed by the fixing device 13 and discharges it to the outside of the apparatus main body 1.

1 and 2 show the essential parts of an image forming apparatus according to an embodiment of the present invention. The overall configurations of the developing device 3 and the hopper 5 provided in the image forming apparatus according to the embodiment of the present invention are substantially the same as those described in FIGS. 4 to 6, but one embodiment of the present invention In the image forming apparatus according to the example, the developer replenishing port for constantly replenishing the developer to the developing device 3, that is, the developer discharge port 5a of the hopper 5, regardless of the change in the relative positional relationship between the hopper 5 and the developing device 3. The hopper 5 and the developing device 3 are arranged so that the hopper 5 and the developer receiving port 3b of the developing device 3 are in communication with each other, and when the hopper 5 rotates, the developer discharging port 5a and the developer receiving port 3b. Rotate around and
When the developing device 3 moves, the hopper 5 also moves together with the developing device 3. In addition,
Regarding the same thing as shown in FIGS. 4 to 6,
The same reference numerals are given and the description thereof is omitted.

In FIG. 1, the hopper hinge 115 is slidably held in the left and right direction in FIG. 1 by a step screw or the like on the front side plate (not shown) of the image forming apparatus main body 1 described above. The hopper hinge 115 is provided to rotatably support the hopper 5 described above, and is formed so that the entire cross section has a substantially U shape, and the projection of the hopper 5 is provided on the upper portion.
A recess 115a is formed so that the 5c can be fitted therein, and a hole 115b is formed in the lower portion so that the rotating portion 103 of the hopper 5 can be fitted therein. A cut-and-raised portion 116 is vertically provided below the hopper hinge 115. As described above, the protrusion 5c is formed on the upper side of the portion of the hopper 5 supported by the hopper hinge 115, and can be fitted into the recess 115a of the hopper hinge 115. As described above, the hopper rotating portion 103 is integrally attached and fixed to the main body of the hopper 5 by means of screw fastening or adhesion as described above, below the portion of the hopper 5 supported by the hopper hinge 115.
It is possible to fit with the hole 115b of 5. The hopper rotating portion 103 will be further described. The hopper rotating portion 103 is formed with a hole 106 having a diameter considerably larger than that of the developer discharge port 5a formed on the lower surface of the hopper 5. The lower surface of the moving part 103 has a hole slightly larger in diameter than the hole 106 of the hopper rotating part 103.
A cushion member 104, on which 107 is formed, is adhered and attached. A flexible sheet or plastic member 105 in which a hole 108 having a diameter slightly larger than the hole 107 of the cushion member 104 is formed on the lower surface of the cushion member 104.
Is pasted. The cushion member 104, when the hopper 5 is supported by the hopper hinge 115,
The elastically deformed state is kept constant, and the developer T falling from the hopper 5 through the developer discharge port 5a is prevented from scattering. Incidentally, the hopper rotating portion 103, the cushion member 104, the flexible sheet or the plastic member 105 described above.
Is attached so that the centers of the holes 106, 107, and 108 are aligned with each other, so that the developer T falling from the developer discharge port 5a can be smoothly stored in the developer receiving port 3b of the developing device 3. Has become. The developing device 3 is fitted and fixed on a developing device rail 112 which is movable in the left-right direction in FIG. 1 by a driving means (not shown), and when the developing device rail 112 moves in the left-right direction in FIG. Are arranged so as to come close to or apart from the photosensitive drum 2. Developer rail 112
A hook member 113 is integrally fixed to the developer rail 112 by welding, screwing, or the like, and a through hole is formed in the hook member 113. The cut-and-raised portion 116 is fitted. The fitting position of the cut-and-raised portion 116 with respect to the hook member 113 is the hopper 1 supported by the hopper hinge 115.
It is assumed that the position of the developer discharge port 5a of 15 and the position of the developer receiving port 3b of the developing device 3 fitted and fixed on the developing device rail 112 are selected to coincide with each other.

With the configuration described above, the hopper 5 is the hopper 5
At the time of replenishment of the developer to itself, points 110 shown in FIGS. 1 and 2 (namely, the developer discharge port 5a and the developer receiving port 3b)
2) centered on a point corresponding to the approximate center of
It becomes possible to rotate in the direction. When the developing device 3 moves along with the movement of the developing device rail 112 to the right in FIG. 1, the hopper hinge 115 also moves to the right in FIG. 1, so that the hopper 5 moves to the right in FIG. Therefore, the developer discharge port 5a and the developer receiving port 3b are kept in communication with each other.

As described above, according to the embodiment of the present invention, the position of the developer discharge port 5a of the hopper 5 and the position of the developer receiving port 3b of the developing device 3 are made to coincide with each other, and the developer discharge port 5a and the developer are discharged. Since the developer receiving port 3b is rotated about the developer receiving port 3b, the developer discharging port 5a and the developer receiving port 3b are always in an open state and communicate with each other, like when a conventional shutter mechanism is provided. Since there is no opening / closing operation of the shutter member, the developer can be completely prevented from scattering into the main body of the image forming apparatus, and the cost reduction of the apparatus can be realized by removing the extra mechanism. It has become possible.

As described above, according to the present invention, the developer replenished from the developer replenishing means to the developing means during the movement of the developer replenishing means is scattered from the developer replenishing means into the main body of the image forming apparatus. By providing such an image forming apparatus, it is possible to prevent the apparatus itself from malfunctioning, contaminate the manuscript or transfer material, and sometimes even the operator's hand or clothes. You can

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view showing a main part of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a plan view showing a main part of the image forming apparatus according to the embodiment of the present invention. FIG. 3 is a sectional view showing the overall structure of the image forming apparatus according to the embodiment of the present invention. FIG. 4 is a partial plan view showing a developing device and a hopper included in the image forming apparatus according to the conventional technique. FIG. 5 is a partial front view showing a developing device and a hopper included in the image forming apparatus according to the prior art. FIG. 6 is an operation explanatory view of a developing device, a hopper, and a shutter included in the image forming apparatus according to the conventional technique. 3: Developing device 3b: Developer receiving port 5: Hopper 5a: Developer discharging port 5c: Projection part 103: Hopper rotating part 104: Cushion member 105: Flexible sheet or plastic member 112: Developing device rail 113: Hook member 115: Hopper hinge 116: Cut and raised member

Claims (1)

(57) [Claims] 1. A developing device having an image bearing member carrying a latent image, a developer receiving port capable of moving between a developing position adjacent to the image bearing member and a separating position spaced from the image bearing member, and the developing unit. A hopper having a developer replenishment port for replenishing the developer to the container, the hopper being movable between a replenishment position where an operator replenishes toner and a storage position accommodated in the main body. The hopper moves integrally with the developing device, and the hopper rotates around the developer replenishing port, so that the developer receiving port and the developer replenishing port are aligned regardless of the movement of the developing device and the hopper. An image forming apparatus characterized by the above.