JP2001134063A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device that an image of high quality can be obtained by preventing toner scattering with a simple constitution when toner is supplied from outside to a toner replenishing device. SOLUTION: Relating to the image forming device provided with an image carrier 220 where a latent image is formed, at least one developing device 204 to develop the latent image on the image carrier and a toner replenishing device 200 to supply the toner from outside to the developing device 204, a top surface part of the image forming device including an operation part where operation such as starting of an image forming action is carried out is arranged t be freely movable and relating to the toner replenishing device 200, a toner replenishing opening 201 for the toner replenishing device is positioned below the top surface part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various electrophotographic or electrostatic recording type image forming apparatuses such as a color electrophotographic copying machine, a computer printer, and a facsimile output unit. The present invention relates to a toner replenishing device for replenishing toner to a developing device used to visualize a latent image in an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic method, an electrostatic latent image formed on the surface of an image carrier such as a photoreceptor is developed by a developing device and visualized as a toner image. I do.

Conventionally, when the toner in the developing device has a density lower than a predetermined density, the toner is replenished to the developing device by a toner replenishing device. However, the amount of toner stored in the toner replenishing device is reduced. In this case, toner must be supplied to the toner supply device from outside.
The replenishing means can be roughly classified into two forms.
One of them is a configuration in which a container for accommodating the toner itself is replaced when replenishing the toner. In the toner replenishing apparatus of this embodiment, for example, in a color electrophotographic copying machine, it is very difficult to use a common container for each of the yellow toner, magenta toner, cyan toner, and black toner, and, consequently, a common container for other models. . As a result, there is a problem that the types of the containers to be replaced each time toner is replenished increase, and a cost increase cannot be avoided.

Another form of the toner replenishing device is an object to which the present invention is directed, and has a configuration in which the toner is replenished to the toner container of the toner replenishing device from outside by using another container. is there. In the toner replenishing apparatus of this embodiment, for example, in a color electrophotographic copying machine, the shape of the container for replenishing the toner of each color from outside is not restricted by the inside of the apparatus, so that it is possible to use a common container. This is advantageous in that a common container can be used.

It is generally known that the toner replenishing device of this embodiment is formed on the front surface in consideration of user's workability, and is pulled out at the time of toner replenishment.

Next, another conventional apparatus will be described.
2. Description of the Related Art A conventional image forming apparatus such as a color copying machine has three or four developing devices. In recent years, since UCR and the like can be performed by digital processing, four colors, that is, cyan, magenta,
An apparatus having four developing devices in which black is added in addition to the three primary colors of yellow is increasing. However, it is difficult to efficiently store the hoppers of the respective colors in the developing device having such a large number of colors, and thus a small hopper having a reduced hopper capacity is arranged compactly.

[0007]

However, the above conventional example has the following problems.

In the above-described conventional toner replenishing device, the toner replenishing device and the developing device are disconnected from each other at the time of toner replenishment, or the toner replenishing device is attached to or detached from the device due to vibration or impact. However, there is a problem that the toner is scattered from the toner replenishing device to the floor or the inside of the apparatus, thereby contaminating the surroundings, or preventing high-quality image formation due to color mixing or the like.

In order to solve this problem, a shutter mechanism is provided at a toner supply port of the toner supply device to prevent toner scattering, and a slide mechanism which is detachable from the apparatus has a damper function to prevent vibration and impact. However, in order to improve the reliability, there is a problem that the configuration is complicated, the device is enlarged, and the manufacturing cost is increased.

The hopper of the above-described color copying machine has the following problems. In other words, in the conventional type in which the developing device is moved in parallel or rotationally in the device, the position of the developing device with respect to the photosensitive drum is fixed, so that the size and arrangement of the hopper still have a degree of freedom. When a developing device that does not move around the drum is provided, the developing device disposed above tends to obstruct toner supply to the next adjacent developing device because the toner is normally dropped and supplied in front of the developing device. Further, there is a problem that the capacity of the hopper is further reduced because the length of the hopper for replenishing the developing device disposed above is difficult to take in the height direction. In particular, even in a color copying machine, since the number of black and white copies is large, the number of black toner replenishments tends to increase inevitably as compared with other colors.

A first object of the present invention is to solve the above-mentioned problems and to prevent toner scattering with a simple structure when supplying toner from the outside to a toner supply device, and to obtain a high quality image. It is an object of the present invention to provide an image forming apparatus capable of performing the above.

A second object of the present invention is to provide an image forming apparatus capable of securing a predetermined capacity even when there is a restriction on the arrangement of hoppers.

[0013]

According to the first invention of the present application,
The first object is to provide an image carrier on which a latent image is formed, at least one developing device for developing the latent image on the image carrier, and a device for externally supplying toner to the developing device. In an image forming apparatus provided with a toner replenishing device, an upper surface portion of the image forming device including an operation unit for performing operations such as starting an image forming operation is movably disposed. This is achieved because the toner supply port for the toner supply device is located below the upper surface.

Further, according to the second invention of the present application, the second object is to provide an image bearing member for carrying a latent image and at least two or more developing members arranged along the rotation direction of the image bearing member. In an image forming apparatus having a developing device and a toner replenishing device for replenishing toner to the developing device, a toner replenishing portion of the developing device or the toner replenishing device located above is provided above the image forming device or on the surface of the image carrier. The image forming apparatus is formed on the side opposite to the image forming apparatus, and the toner replenishing portion of another developing device or the toner replenishing device is achieved by being formed in front of the image forming apparatus on the end surface side of the image carrier. .

According to the first aspect of the present invention, since the toner supply port of the toner supply device is located below the movable upper surface, the toner is supplied by moving the operation plate during toner supply. This eliminates the need for operations such as separation of the toner replenishing device and the developing device, and does not cause toner scattering.

According to the second aspect of the present invention, of the plurality of developing devices and the toner replenishing device, the toner replenishing portion of the one located above is formed at a position different from the toner replenishing portion of the other developing device and the toner replenishing device. The capacity of each of the developing device and the toner replenishing device is increased by being placed above or beside the image forming device.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1> FIG. 1 shows Embodiment 1 of the present invention.
A description will be given with reference to FIG. FIG. 1 shows an embodiment in which the image forming apparatus of the present invention is embodied in an electrophotographic copying machine for forming a full-color copy image.

As shown in FIG. 1, a photosensitive drum 220 as an image carrier for carrying an electrostatic latent image according to the present embodiment is carried rotatably in the direction of an arrow. Around the photosensitive drum 220, a corona charger 202, an exposure optical device 203, a developing device 204, a transfer system 205, and a cleaning device 206
Are arranged.

A document reading system 207 is provided above the apparatus, and includes a document scanning unit 207a and a photoelectric device 207b having a color separation filter. An electrostatic latent image is formed on the photosensitive drum 220.

The developing device 204 includes a yellow developing unit 204Y using yellow toner, a cyan developing unit 204C using cyan toner, a magenta developing unit 204M using magenta toner, and a black developing unit 204BK using black toner.
And two developing units.

On the other hand, the transfer system 205 is
A transfer drum 205b having a transfer drum 205b, and a transfer discharger 205c disposed inside the transfer drum 205b.
The toner image is transferred to the recording material from the photosensitive drum 220 at the transfer position by charging the toner image to a polarity opposite to that of the toner development of 0. This is sequentially repeated for each toner to form a full-color image on the recording material. The recording material is supplied from the cassette 208 or the manual feed unit 209. When the transfer is completed, the recording material is separated from the transfer drum 205b by the separating unit 210, conveyed to the fixing unit 211, and fixed on the tray. 212.

FIG. 2 shows the developing units 204Y and 204Y.
The relationship between the arrangement of 04C, 204M, and 204BK and the arrangement of each toner storage unit (hopper) with respect to the arrangement is shown.

The toner replenishing device 200 includes a yellow toner hopper 200Y, a cyan toner hopper 200C, a magenta toner hopper 200M, and a black toner hopper 200BK containing the color toner to be supplied to each developing unit.
To the photosensitive drum 220 in the same order as the developing unit.
Is fixed to a support frame 200a provided on one end side of the frame. The support frame 200 a is pivotally supported by a pivot 203, and is used when the photosensitive drum 220 is maintained.
3, the hopper is taken out to an appropriate position outside the apparatus, and the space behind the hopper can be opened. However, the hopper is substantially fixedly held to the developing device 204.

Each hopper has a supply port 201 (201Y, 201C, 201) for supplying toner from outside.
M, 201BK).

The developing units 204Y, 204C, 2
04M and 204BK are the toner receiving ports 250 (25
0Y, 250C, 250M, 250BK) through the toner replenishing device 200 (200Y, 200C, 200B).
M, 200BK) to contribute to development.

Next, a method of supplying toner in this embodiment will be described. FIG. 3 is an external view of the full-color electrophotographic copying machine. An original reading device 2 is provided on the upper surface of the copying machine.
71, and an operation unit 213 including an execution unit 214 for executing copying and a display unit 215 for displaying an execution state. The operation section 213 is supported rotatably about a pivot 213a.

When toner is supplied from the outside to the toner replenishing device, as shown in FIG. 4, the operation section is rotated in the direction of an arrow to replenish the toner supply port 201 (201) of the toner replenishing device.
Y, 201C, 201M, 201BK).

When supplying black toner, for example, as shown in FIG.
The toner is connected to the supply port 201BK, and the toner is dropped into the black toner hopper 200BK and supplied.

At this time, the toner replenishing device 200 is fixed, and the connection with the developing device (not shown) is maintained.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. Note that the same reference numerals will be described for the common parts with the first embodiment.

In this embodiment, only the upper portion of the toner replenishing device 200 is rotated about a pivot 213b to open. In the illustrated example, the toner supply device 200
Is located at the right end, the operation section movable section 213b is formed at the right end. However, the position may be any position within the range of the operation section 213 depending on the position of the toner supply device 200.

In the illustrated example, the execution section 214 is formed on the movable section and the display section 215 is formed on the fixed section. However, the order may be reversed. Further, the execution unit 214 and the display unit 215 may be formed on the movable unit side.

Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description is omitted.

The present embodiment has a structure in which the operation unit 213 is pulled out horizontally above the guide member 217 to open the upper portion of the toner supply device 200. In the illustrated example, the entire operation unit 213 is pulled out.
Alternatively, only the upper part of 00 may be opened.

The first to third embodiments are based on the premise that the toner replenishing device and the developing device are detachable.
These may be an integral structure that cannot be detached.

Embodiment 4 Next, Embodiment 4 of the present invention.
Will be described with reference to FIGS.

In FIG. 7, reference numeral 301 denotes an original pressure plate,
02 is pressed against the original glass 303. The document 302 is illuminated by an illumination lamp 304 and is moved by a first mirror 305 moving at a speed v, a second mirror 306 moving at a speed v / 2, and an image sensor 308 by a lens 307.
To form a light image. The signal of the image sensor 308 is
9 and is input to the laser scanner 310.

The copy paper 320 is picked up by a paper feed roller 321, then fed by a lower registration roller 322, passes through a lower guide 323, and passes through a registration roller 324.
Is transferred to the transfer drum 328 at an appropriate timing. The copy paper 320 sent to the transfer drum 328 passes through the guide 325 and the suction brush 327 and the suction roller 326.
As a result, the toner is electrostatically attracted to the transfer drum 328 which is formed of a cylindrical resin film and rotates in the direction of the arrow shown in the figure.

On the other hand, the image forming drum 311 rotates in the direction of the arrow shown in the figure, and is uniformly charged by the primary charger 312. A fan or duct for removing air is provided on the back of the primary charger 312 so that ionized air, ozone, and the like do not accelerate the deterioration of the image forming drum 311.

An image is written on the uniformly charged image forming drum 311 via the polygon mirror 313 and the deflecting mirror 314 by the laser scanner at the position of the image writing section 315 to form an electrostatic latent image. Is done. The electrostatic latent image is visualized by a magenta toner in a magenta developing device 316 and is transferred by a transfer brush 329 to a copy sheet adsorbed on a transfer drum. In a similar process, toners of a total of four colors by the cyan developing device 317, the yellow developing device 318, and the black developing device 319 are transferred onto the same copy paper. Next, the transfer drum 32 is moved by the outer static eliminator 331 and the inner brush 330.
8. Removes electricity from the copy paper 320 and pushes up the roller 332.
And push up the resin film of the transfer drum,
The separation claw 333 is pressed against the resin film to peel off the electrostatically attracted copy paper.

Next, the copy paper is sent to an entrance guide 336 by a transport belt 334 suspended by rollers 335.
A suction fan 337 is provided in the transport belt 334 for the purpose of stabilizing the transport of the copy sheet by the transport belt 334, and the suction fan 337 pulls air from the rear surface of the transport belt. The copy paper thus conveyed enters a pressure contact portion between the fixing roller 338 and the pressure roller 339, and after the toner is fixed on the copy paper at the pressure contact portion,
The sheet is discharged onto a tray 342 by a sheet discharging roller 341 through a sheet discharging guide 340.

In the apparatus of the present embodiment as described above, the uppermost developing device 319 is a developing device that performs jumping development using one-component insulating toner, and falls uniformly to the developing device in the generatrix direction of the photosensitive drum. And a hopper type toner replenishing device. Arranging a developing device for developing black at this location requires a large-capacity hopper 403.
Can be arranged on the upper portion of the developing device 319. Considering the toner used for jumping development, since it contains various additives although it is one component, if a configuration is adopted in which toner is dropped and supplied to one end (for example, the front side) of the developing device and fed by a screw or the like, the toner Although the developing characteristics change because the mixing ratio of the additive and the additive is different between the front and the back, it is not preferable. However, such a defect can be solved by performing uniform drop replenishment.
Also, in the jumping development, the developer does not contact with the photosensitive drum, so that even when developing other than black, it is not necessary to separate the developing device from the photosensitive drum, simply turn off the developing bias, and the developing sleeve does not rotate. In this case, the latent image on the photosensitive drum is not disturbed or developed, and if the development of other colors is a contact development type, it is best to place it at the most upstream position. It is.

Next, the arrangement of the hopper and the position of the toner supply opening to the developing device will be described with reference to FIG. 8 when the hopper is viewed from above and FIG. 9 when viewed from the front front side.

In FIG. 8, reference numeral 401 denotes an apparatus back side plate;
Is a front plate of the apparatus, and the hopper 403 of black toner has a supply opening 403a at the bottom. Replenishment is performed by a known method such as rotation of a magnet roller or a sponge roller provided at the replenishing opening, so that uniform drop replenishment is performed at any position in the longitudinal direction of the opening.

Reference numeral 404 denotes a magenta toner hopper having an opening 404a at the bottom. Replenishment is a known method,
For example, as shown in FIG. 18, toner is fed by a screw 404b toward an opening 404a of the magenta developing device 316, and dropping replenishment is performed.

Similarly, reference numeral 405 denotes a hopper for cyan toner and 405a denotes an opening thereof, and 406 denotes a hopper of yellow toner and 406a denotes an opening thereof. Since the magenta hopper has a high supply port in relation to the supply port of the developing device, the size of the magenta hopper is set to be larger in the horizontal direction and the capacity is the same as that of the cyan and yellow hoppers. .
Reference numeral 407 denotes a hinge center axis, which allows the entire hopper to be opened and closed in the direction of the arrow. In the opened state, the developing device can be inserted and removed, and other maintenance can be performed. The black hopper was placed between the front and rear plates of the device, so magenta, cyan,
The capacity of the yellow hopper can be increased by 33% or more, and the capacity of the black hopper can be extremely large.

Next, replenishment of toner to the hopper will be described. The magenta, cyan, and yellow toner can be replenished by opening the front door (not shown) and replenishing the toner from the upper part of the hopper by a known method since the hopper is disposed outside the front plate 402 of the apparatus. That is, the lid 404c is opened and replenished with a bag or a replenishing container.

The replenishment of the black toner is troublesome because the black hopper is still hidden behind the magenta / cyan / yellow hopper even when the front door is opened. Accordingly, as shown by the two-dot chain line in FIG. 7, the right side door 343 is opened, the replenishment container 408 is guided from above, the replenishing container 408 is inserted from the side in the direction of the arrow, and then the shutter 408a is opened, so that replenishment can be performed. is there. As another replenishing method, as shown in FIG. 10, a replenishing bottle 409 can be connected to the hopper 403 and replenished from the upper part of the apparatus. In the case of this method, the space between the front side plate and the rear side plate of the apparatus can be effectively used, so that the hopper can have a larger capacity.

To replenish the toner of magenta, cyan and yellow, open a large front door, and further perform necessary operations, for example, open an operation panel, then open a lid of a hopper, connect a replenishing container with the hopper and replenish by dropping. However, since the consumption of the color toner is not as large as that of black, the frequency is low and the frequency is low, so that it is practically acceptable that the color toner is somewhat complicated. However, since the frequency of black is high, simple is preferable.

In any of the above cases, the operation is simpler than the conventional example in which the front door is always opened and the method is suitable for a method of refilling black toner. In particular, in the latter method, the lid at the top of the hopper is only opened and the refill bottle is connected, which is easy.

When the developer is a one-component toner that does not require a carrier, a hopper portion is not necessarily required. Therefore, a large developing container may be formed and toner may be directly supplied to the container. Of course.

[0053]

As described above, according to the first aspect of the present invention, the toner supply port of the toner supply device is located below the movable upper surface of the main unit, so that the toner supply device and the toner supply device can be connected to each other. It is possible to replenish toner from the outside without releasing the connection with the developing unit, and it is possible to prevent toner scattering with a simple configuration and to form a high quality image.

According to the second invention of the present application, the toner supply unit of the uppermost developing device or toner supply device is located above or beside the image forming apparatus, so that the capacity of the toner supply device of any color can be increased. And the method of replenishing the toner to the upper developing device or the toner replenishing device becomes simpler than replenishing to other hoppers.

[Brief description of the drawings]

FIG. 1 is a sectional view of a full-color electrophotographic copying machine according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a toner supply device in the apparatus of FIG.

FIG. 3 is a perspective view showing the vicinity of an operation unit of the apparatus shown in FIG. 1;

FIG. 4 is a view for explaining a method of externally supplying toner to the apparatus in FIG. 1;

FIG. 5 is a diagram illustrating a positional relationship between a toner supply port and an operation unit of the toner supply device according to the second embodiment of the present invention.

FIG. 6 is a diagram illustrating a positional relationship between a toner supply port of a toner supply device and an operation unit according to a third embodiment of the present invention.

FIG. 7 is a sectional view of an image forming apparatus according to a fourth embodiment of the present invention.

8 is a top view of the toner supply device of FIG. 7;

9 is a front view of the toner supply device of FIG. 7;

FIG. 10 is a cross-sectional view illustrating another toner replenishing method in the apparatus in FIG. 7;

[Explanation of symbols]

200Y, 200C, 200M, 200K Toner replenishing device 201Y, 201C, 201M, 201K Toner replenishing port 204Y, 204C, 204M, 204K Developing unit (developing device) 213 Operation unit (upper part) 316 Magenta developing device 317 For cyan color Developing device 318 Yellow developing device 319 Black developing device (developing device located above) 403 Black hopper (toner supplying device) 404 Magenta hopper (toner supplying device) 405 Cyan hopper (toner supplying device) 406 Yellow hopper (toner supply device)

Claims (6)

[Claims] An image carrier on which a latent image is formed, at least one developing device for developing the latent image on the image carrier, and a toner supply for externally supplying toner to the developing device In the image forming apparatus provided with the image forming apparatus, an upper surface portion of the image forming apparatus including an operation unit for performing operations such as starting an image forming operation is movably disposed. An image forming apparatus, wherein a toner supply port to the apparatus is located below the upper surface. 2. An image carrier for carrying a latent image, at least two or more developing devices arranged along a rotation direction of the image carrier, and a toner replenishing device for replenishing toner to the developing device. In the image forming apparatus having the above, the toner replenishing portion of the developing device or the toner replenishing device located above is formed above the image forming device or on the side of the image forming device opposite to the surface of the image carrier, and An image forming apparatus, wherein the toner supply section of the developing device or the toner supply device is formed in front of the image forming apparatus on the end surface side of the image carrier. 3. A toner replenishing device for replenishing toner to an upper developing device is provided substantially between a front plate and a rear plate of an image forming device, and replenishes toner to another developing device. The image forming apparatus according to claim 2, wherein: is provided on a front side of the front side plate. 4. The image forming apparatus according to claim 2, wherein the toner supplied to the upper developing device is a black toner. 5. The toner supply device according to claim 2, wherein the capacity of the toner replenishing device for replenishing toner to the developing device located above is larger than the capacities of the other toner replenishing devices. Image forming device. 6. The developing device according to claim 2, wherein the developing device located above performs the development without bringing the surface of the image carrier into contact with the developer on the developer carrier. The image forming apparatus as described in the above.