JPH09325590A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size and cost of a device by making a developer carrying means composed of a means for forming a developer moving path and a means for feeding a developer housed in the lower part of a developing container to a developer receiving port. SOLUTION: The developer carrying means is composed of the developer moving path forming means and the toner feeding member 13a. The developer moving path forming means has the developer receiving port 13h on the lower part side of the developing container 5a and a developer discharge port 13g on the side of a toner carrier 5b and is composed of a plate-like member 13d for forming a toner moving path 13c from the developer receiving port 13h to the developer discharge port 13g, etc. The toner feeding member 13a feeds toner housed in the lower part of the developing container 5a to the developer receiving port 13h. In this constitution, as the toner moving path 13c, space in such a degree that the developer can be moved is only secured and the toner feeding member 13a only feeds the developer to the receiving port 13h, so that the toner feeding member 13a can be miniaturized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device used in an image forming apparatus such as a copying machine, a facsimile machine or a printer, and more specifically, to a developer carrying member partially exposed from an opening formed in an upper part of a developing container. On the other hand, the present invention relates to a developing device that conveys the developer contained in the lower portion of the developing container.

[0002]

2. Description of the Related Art In recent years, a personal image forming apparatus that is small in size, light in weight, easy to carry, and low in cost has been required due to the remarkable spread of personal word processors and personal computers. Along with this, downsizing and cost reduction of the developing device used in the image forming apparatus are also problems.

On the other hand, as a developing device used in an image forming apparatus, conventionally, a developing agent contained in a lower portion of a developing container is held against a developer carrying member partially exposed from an opening formed in an upper portion of the developing container. A developing device that conveys the agent is known (see, for example, JP-A-55-11860 and JP-A-61-173956).

[0004]

However, in the above-described conventional developing device, it is difficult to achieve downsizing and cost reduction due to the provision of the developer conveying means. For example, as disclosed in JP-A-55-118060 and JP-A-61-173956, a plurality of conveying members (conveying rollers) are arranged between the lower portion of the developing container and the developer carrying member. With the configuration provided, the developing device may be large and the cost may be high.

The present invention has been made in view of the above problems, and an object thereof is to provide a developer carrying member partially exposed from an opening formed in an upper portion of a developing container to a lower portion of the developing container. It is an object of the present invention to provide a developing device that conveys the developer contained in the developing device, which can reduce the size and cost of the device.

[0006]

In order to achieve the above-mentioned object, the invention of claim 1 is directed to a developer carrier which is partially exposed from an opening formed in the upper part of the developing container. A developer carrying means for carrying the developer housed in the lower portion is provided, and the developer carried by the developer carrying means is supplied to the developer carrying body to remove the developer on the developer carrying body. In a developing device for developing a latent image on a latent image carrier using the developer transporting means, a developer receiving port is provided on a lower side of the developing container, and a developer discharging port is provided on a developer carrying side. Structured using an agent moving path forming means for forming an agent moving path from the agent receiving port to the agent discharging port, and an agent feeding means for sending the developer contained in the lower portion of the developing container to the agent receiving port. It is characterized by having done.

A second aspect of the present invention is the developing device according to the first aspect, wherein a roller-shaped member is used as the developer carrier or an intermediate carrier for intermediately carrying the developer supplied to the developer carrier. The agent receiving member for receiving the developer discharged from the agent discharge port of the agent moving path forming means is provided in contact with or close to the surface of the developer carrying member or the surface of the intermediate agent carrying member. The surface is curved along the surface of the developer carrier or the surface of the intermediate carrier.

According to a third aspect of the present invention, in the developing device according to the first aspect, there is provided an agent receiving member for receiving the developer discharged from the agent discharge port of the agent moving path forming means, and the agent receiving member is an excessive developing device. It is characterized in that it has an agent dropping port for dropping the agent into the developing container.

According to a fourth aspect of the present invention, as the intermediate carrier carrying body for carrying the developer carrying body or the developer supplied to the developer carrying body, the one having a movable surface is used. In the developing device, an agent receiving member for receiving the developer discharged from the agent discharge port of the agent moving path forming means is provided, and the agent dropping port is provided in the moving direction of the surface of the developer carrier or the surface of the intermediate carrier. In at least one of the downstream side and the upstream side of the above-mentioned agent receiving member, it is provided so as to extend in the axial direction of the developer carrying member.

According to a fifth aspect of the present invention, in the developing device according to the first aspect, an agent receiving member for receiving the developer discharged from the agent discharge port of the agent moving path forming means is provided, and the surface of the agent receiving member is roughened. It is characterized by being faced.

According to a sixth aspect of the present invention, in the developing device according to the first aspect, the agent receiving member for receiving the developer discharged from the agent discharge port of the agent moving path forming means is the developer carrier or the developer. It is characterized in that the developer supplied to the carrier is provided so as to be in contact with or close to the intermediate carrier which carries intermediately, and the developer receiving member has elasticity.

According to a seventh aspect of the present invention, in the developing device according to the first aspect, the agent moving path forming means faces the inner wall surface of the developing container and the inner wall surface with a gap in which the developer can move. It is characterized in that it is configured by using a plate member provided.

According to an eighth aspect of the present invention, in the developing device according to the seventh aspect, a surface of the plate member facing the inner wall surface is substantially parallel to the inner wall surface.

According to a ninth aspect of the present invention, in the developing device according to the first aspect, the developer feeding means is a rotary conveyance member in which a plate-like member extending in the axial direction of the developer carrier is formed on a rotation shaft. It is characterized by being configured by using. Here, in order to continuously feed the developer in the lower portion of the developing container to the developer transport path, it is preferable to form a plurality of the plate-shaped members.

According to a tenth aspect of the invention, in the developing device of the ninth aspect, the plate-shaped member is in contact with or close to the edge of the agent moving path forming means on the agent receiving port side. Is.

According to an eleventh aspect of the present invention, in the developing device according to the ninth aspect, the plate-shaped member is in contact with or close to the bottom surface of the developing container.

According to a twelfth aspect of the present invention, in the developing device according to the tenth or eleventh aspect, the plate member has elasticity.

In the developing device of the first aspect, the developer accommodated in the lower portion of the developing container is sent from the agent receiving means into the agent moving path formed by the agent moving path forming means from the agent receiving port. The developer sent into the agent moving path moves upward due to its internal pressure and is discharged from the agent discharge port. The discharged developer is supplied to the developer carrier and used for developing the latent image on the latent image carrier.

In the developing device of the second aspect, the developer discharged from the agent discharge port is formed on the surface of the agent receiving member curved along the surface of the roller-shaped developer carrier or the intermediate agent carrier. The developer is received and the developer on the surface of the agent receiving member is supplied in substantially uniform contact with the developer carrying member or the intermediate agent carrying member.

In the developing device of the third aspect, when the developer receiving member receives the excess developer, the excess developer falls into the developing container through the developer dropping port of the developer receiving member.

In the developing device of claim 4, when the amount of the developer received on the agent receiving member is partially excessive in the axial direction of the developer carrying member, it is partially excessive. Through the agent dropping port provided so that the developer extends in the axial direction of the developer carrying body on at least one of the downstream side and the upstream side in the moving direction of the surface of the developer carrying body or the surface of the intermediate carrying body. , Drop into the developing container.

In the developing device according to the fifth aspect, the surface of the agent receiving member is roughened to increase the holding force of the developer by the surface, and this occurs when the developer carrier or the intermediate carrier is driven. Prevent the developer on the developer receiving member from falling into the developing container due to vibration or frictional force.

In the developing device of the sixth aspect, since the agent receiving member has elasticity, when a large amount of the developer stays between the agent receiving member and the surface of the developer carrier or the surface of the intermediate carrier. , The developer receiving member is deformed so that excessive pressure is not applied to the developer.

In the developing device of claim 7, an agent moving path is formed by an inner wall surface of the developing container and a plate-like member provided so as to face the inner wall surface with a gap in which the developer can move. The developer accommodated in the lower portion of the developing container moves through the agent moving path toward the agent discharge port on the upper side of the developer carrier.

In the developing device according to the eighth aspect, the facing surface of the plate-like member forming the agent moving path and the inner wall surface is substantially parallel to the inner wall surface. Is almost constant in the axial direction of the developer carrying member.

In the developing device according to the ninth aspect, the developing container is a plate-shaped member extending in the axial direction of the developer carrying member formed on the rotation axis of the rotary transport member by the rotation of the rotary transport member. The developer existing in the lower part of is fed toward the agent receiving port of the agent moving path.

In the developing device according to the tenth aspect, when the rotary conveying member rotates and sends the developer toward the agent receiving port of the agent moving path, the plate member of the rotary conveying member forms the agent moving path. By contacting or approaching the edge of the means on the agent receiving side, the developer adhering to the plate-shaped member is scraped off by the edge and fed into the agent moving path.

In the developing device according to the eleventh aspect, when the rotary conveying member rotates and sends the developer toward the agent receiving port of the agent moving path, the plate-shaped member of the rotary conveying member is the bottom surface of the developing container. By contacting or approaching the developer, the developer existing in the portion near the bottom surface of the developing container is scraped and sent to the agent receiving port of the agent moving path.

In the developing device according to the twelfth aspect, when the elastic plate-shaped member of the rotary conveying member comes into contact with or approaches the edge of the agent moving path forming means, or comes into contact with the bottom surface of the developing container. When approaching, it deforms so that excessive pressure is not applied to the developer.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is applied to a developing device of a full-color image forming apparatus will be described below. FIG. 1A is a schematic configuration diagram of one image forming unit of the full-color image forming apparatus according to this embodiment. A drum-shaped photoconductor 1 as a latent image carrier rotates in the direction of arrow A1, and around the photoconductor 1, a roller charger 2 as a charging unit and a non-magnetic toner (hereinafter referred to as a non-magnetic toner) as a non-magnetic one-component developer. A developing device 5, which uses “toner” 4.
A transfer device 6, a cleaning device 11, an erase lamp 12 as a charge removing unit, and the like are provided. An exposure device 3 is provided inside the photoconductor 1.

The photoreceptor 1 is a transparent photoreceptor comprising a transparent substrate, a transparent electrode provided on the transparent substrate, and a photosensitive layer provided on the transparent electrode. I am using. Examples of the photosensitive layer of the photoconductor 1 include a Se-based photoconductor layer formed by vacuum deposition, a binder-type photoconductor layer in which ZnO, CdS photoconductive microcrystals formed by coating are dispersed in a binder such as a resin, and sputtering. The formed amorphous silicon photoconductor layer, organic photoconductor layer, or the like can be used.

Further, another charger such as a corona charger may be used in place of the roller charger 2 described above, but when the roller charger 2 is used as in this embodiment, space saving is achieved. It is advantageous in that it can be used and that ozone is less generated.

As the exposure device 3, an LED array provided inside the photoconductor 1 is used. As the exposure device 3, in addition to the above LED array, a device using a laser device, a liquid crystal shutter array, or the like can be used. By providing the exposure device 3 inside the photoconductor 1 as described above, a space for the exposure on the outside of the photoconductor 1 is almost unnecessary. Further, since the exposure device 3 is provided inside the photoconductor 1, the exposure device 3 is not contaminated by dust existing on the outside of the photoconductor 1, so that maintenance of the exposure device 3 that greatly affects an image is performed. This can be omitted, and a highly reliable image forming apparatus can be configured.

Further, as shown in FIG. 1A, the developing device 5 is provided below the photoconductor 1, and the endless belt-shaped intermediate transfer member 6a rotating in the direction of arrow A2 of the transfer device 6 is exposed. It is provided above the body 1 so as to extend in the horizontal direction. In this way, the developing device 5 and the transfer device 6 are connected to the photoconductor 1 respectively.
By providing the exposure device 3 above and below the photoconductor 1 and the exposure device 3 inside the photoconductor 1 as described above, even when the photoconductor 1 having a relatively small diameter is used, the vertical plane including the rotation axis of the photoconductor 1 is provided. It is possible to secure a sufficient space for disposing the charging device 2 and the cleaning device 11 in only one of the two spaces existing on both sides of the photoconductor 1 with the space therebetween. Further, in this way, the charging device 2, the exposure device 3, the developing device 5, the transfer device 6, and the cleaning device 11 are provided.
When the image forming unit is configured by arranging the same, etc., it is possible to reduce the size of the image forming apparatus that forms multiple images such as full-color images by providing a plurality of such image forming units in the horizontal direction as in the present embodiment. .

FIG. 2 is a schematic block diagram of the entire full-color image forming apparatus according to this embodiment. This full-color image forming apparatus includes a photoconductor 1 and a developing device 5 shown in FIG.
Four image forming units 100 including the above are provided in the horizontal direction. Then, the toner of the developing device 5 of the image forming portion 100Y is yellow toner, the toner of the developing device 5 of the image forming portion 100M is magenta toner, the toner of the developing device 5 of the image forming portion 100C is cyan toner, and the toner of the image forming portion 100BK is developed. By using the toner of the apparatus 5 as black toner and performing corresponding image exposure on each photoconductor 1, a full-color image can be formed.

In each image forming section 100, the photosensitive member 1 rotating in the direction of arrow A1 is uniformly charged by the roller charger 2. Photoreceptor 1 uniformly charged by charger 2
Is exposed by an unillustrated original or image light corresponding to an image signal by the exposure device 3, and an electrostatic latent image corresponding to the light amount of the image light is formed on the photoconductor 1. The electrostatic latent image on the photoconductor 1 is developed in the developing section D by the developing device 5, and the toner 4 adheres to the photoconductor 1 corresponding to the electrostatic latent image to be visualized.

The toner image formed on the photoreceptor 1 is
At the first transfer position T1, on the intermediate transfer body 6a of the transfer device 6, a predetermined pressure is applied to the toner image on the photosensitive body 1 by the first transfer roller 6b to which a transfer bias voltage is applied from a power source (not shown). The intermediate transfer member 6 is brought into pressure contact.
is transferred onto a. At the second transfer position T2, the toner image transferred to the intermediate transfer member 6a is transferred to the transfer paper 7 as a transfer material by the second transfer roller 6c and the counter roller 8 to which a transfer bias is applied from a power source (not shown). The toner image on the intermediate transfer body 6a is transferred to the transfer paper 7 by pressing it with a predetermined pressure.

At the second transfer position T2, the transfer paper 7
After the toner image is transferred to the intermediate transfer body 6a, the toner adhering as a transfer residue on the intermediate transfer body 6a is disposed so as to face the support roller 6d of the intermediate transfer body 6a. Are removed by. The intermediate transfer member cleaning unit 9 uses a blade cleaning method using a blade (not shown), but other methods such as a cleaning method using a rotary brush or a pressure contact roller can of course be used. After the residual toner on the intermediate transfer body 6a is removed in this way, the electric charge remaining on the intermediate transfer body 6a may be removed by a static eliminator (not shown) if necessary. By performing this charge removal, the transfer rate at the time of transferring the toner image formed on the photoconductor 1 at the first transfer position T1 onto the intermediate transfer body 6a again is improved, and at the same time, non-uniformity such as an afterimage is caused. Transfer can be prevented. In this way, the intermediate transfer body 6a is initialized to be in a reusable state, and is again prepared for the transfer process at the first transfer position T1.

The transfer paper 7 on which the toner image has been transferred at the second transfer position T2 is conveyed to a fixing device (not shown), and the toner image is fixed on the transfer paper 7 by the fixing device to form a permanent image. It It should be noted that the transfer sheet 7 conveyed from a sheet feeding unit (not shown) ensures that the toner image transferred to the intermediate transfer body 6a is reliably transferred to a desired position on the transfer sheet 7 at the second transfer position T2. Then, the registration is performed by the registration roller 10 and the sheet is fed toward the second transfer position T2.

After the toner image is transferred to the intermediate transfer member 6a at the first transfer position T1, the toner remaining on the photosensitive member 1 is removed by the cleaning device 11. The cleaning device 11 includes a blade 11 for scraping off toner on the photoconductor 1 by bringing a blade portion into contact with the photoconductor 1.
The blade cleaning method having a is adopted. Toner guide plate 1 provided near the blade 11a
In 1b, the toner scraped off by the blade 11a is excessively accumulated on the photoconductor 1 and grows up to or near the first transfer position T1 and comes into contact with the intermediate transfer body 6a. This is to prevent the generation of the resin, and usually a thin resin film is used. The spiral member 11d provided at the lower part of the cleaning container 11c conveys the toner guided to the lower part of the container 11c toward a toner collecting device (not shown). Here, the toner carried by the spiral member 11d from the lower part of the cleaning container 11c to the toner collecting device is carried toward the developing container 5a of the developing device 5 and reused, which is desirable in reducing the running cost. (Hereinafter, margin)

Electric charges remain non-uniformly on the photoconductor 1 from which the residual toner is removed by the cleaning device 11.
This residual charge causes image defects such as density decrease, fog, and afterimage when the next image is formed. Therefore, the erase lamp 12 removes the charge remaining on the photoconductor 1. In this way, the photoconductor 1 is initialized and prepared for the next image forming operation.

In the image forming apparatus, the intermediate transfer member 6
Although a is used, it is not always necessary to use the intermediate transfer member, and the toner image formed on the photoconductor 1 may be directly transferred onto the transfer paper 7. in this case,
For example, the intermediate transfer member 6a is used as a conveyor belt, and the transfer paper 7 is electrostatically adsorbed to the surface of the conveyor belt by an electrostatic adsorption means (not shown) and conveyed.
The transfer bias application means electrostatically transfers the toner image on the photoconductor 1 directly onto the transfer paper 7. As the electrostatic attraction means, for example, a corona charger, a bias roller provided in contact with a part of the conveyor belt and capable of applying a bias voltage can be used.

Next, the developing device 5 according to the present invention will be described with reference to FIG. The developing device 5 includes the photoconductor 1
And a developing container 5a having an opening facing the above, and as a developer carrying member that comes into contact with or comes close to the photoconductor 1 through the opening of the developing container 5a and carries and conveys toner on the surface while rotating in the direction of arrow A3. Roller-shaped toner carrier 5b
And a roller-shaped toner supply member 5c as an intermediate agent carrier for supplying the toner 4 existing under the developing container 5a to the toner carrier 5b, and the toner carried on the toner carrier 5b in a uniform thin layer. And a toner thin layer forming member 5d as a developer thin layer forming member. A belt-shaped developer carrier may be used instead of the roller-shaped toner carrier 5b.

The toner supply roller 5c rotates in the direction of arrow A4 to supply the toner 4 to the toner carrier 5b uniformly and in an appropriate amount, and at the same time, the toner carrier 5b can carry the toner at the toner supply position S2. The toner carrier 5b enables sufficient frictional charging between the body surface and the toner.
The toner is pressed and rubbed against the surface. Further, the toner thin layer forming member 5d comes into contact with the surface of the toner layer on the toner carrier 5 supplied by the toner supply member 5c, and only the toner layer frictionally charged to a predetermined charge amount is left and excess toner is removed. The toner is scraped off and removed to form a uniform thin toner layer in a single layer on the toner carrier 5b, and the toner is charged to a predetermined polarity and uniformly. In this way, the toner carrier 5b
The toner thin layer formed on the electrostatic latent image formed on the photoconductor 1 by the developing bias voltage applied between the photoconductor electrode (not shown) and the developing electrode of the toner carrier 5b in the developing section D. By selectively adhering to the latent image,
Development takes place.

After the development at the developing position D is completed, the charge on the toner carrier 5b or on the toner is neutralized by the neutralization member 5e, and the electrostatic charge or the toner generated on the toner carrier 5b is mainly generated during the development. It prevents the occurrence of afterimages due to patterns.

The surface of the toner supply member 5c moves in the opposite direction (direction of arrow A4) to the surface of the toner carrier 5b at the toner supply position S1. The toner remaining on the subsequent toner carrier 5b is scraped off by the toner supply member 5c, and new toner is supplied on the toner carrier 5b.
An afterimage is prevented from occurring in the toner image formed during development. In order to more effectively scrape off the toner remaining on the toner carrier 5b, a removing member for removing the residual toner and residual charge on the toner carrier 5b between the charge removing member 5e and the toner supplying member 5c. May be provided. As the charge removing member, for example, a brush-like rotating member provided so as to contact the toner carrier 5b, a blade-like elastic plate, a sponge roller having elasticity, or the like can be widely used.
Further, it is desirable that these removing members have conductivity in order to effectively remove the toner or charges on the toner carrier 5.

As the toner supply member 5c, one that effectively supplies the toner 4 to the toner carrier 5b is desirable. For example, an elastic roller having a porous surface can be used, such as spongecom or urethane foam. A roller having a surface formed of such a resin foam is a particularly desirable example.

The scraping member 5f provided so as to bite into the toner supply member 5c has a toner supply position S1.
In this case, the toner in the vicinity of the surface remaining on the toner supply member 5c that has supplied the toner to the toner carrier 5b is removed. By removing the toner in this way,
For example, when the toner supply member 5c is a sponge roller, it prevents clogging of the sponge and loss of elasticity of the sponge, and at the same time, a stable toner conveying force can be obtained, so that new toner can be supplied and toner carrying It is possible to obtain uniformity of the thin toner layer formed on the body 5b.

Further, the seal along the direction perpendicular to the surface moving direction of the toner carrier 5b has a toner thin layer forming member 5d and a charge removing member 5 which are in contact with the surface of the toner carrier 5b.
achieved by e. If toner is still scattered by this seal alone, a seal member may be provided separately from the above members. As the seal member, a plate-like member provided close to the surface of the toner carrier 5b or an elastic film can be used.

By the way, since the developing device 5 according to the present embodiment uses the non-magnetic toner 4, the toner 4 is electrostatically attached to the surface of the toner carrier 5b or the surface state of the toner carrier 5b. The toner is easily transported because the toner is physically conveyed. In particular, toner scattering is likely to occur at both ends of the opening of the developing container 5a in the axial direction of the toner carrier 5b. The toner scattering generated at both ends of the opening of the developing container 5a is mainly caused by the toner scraped off from the toner carrier 5b by the toner thin layer forming member 5d along the toner thin layer forming member 5d. This is because the amount of toner on both ends of the toner carrier 5b is increased by moving to.
Particularly, when there is a gap between the axial end of the peripheral surface of the toner carrier carrying the toner and the edge of the opening of the developing container 5a, the toner is more likely to be scattered. Further, when the developing device is located on the side of the photoconductor 1 as in the conventional case, the movement of the toner from the developing container to the toner carrier is
Since the movement of the toner itself due to its own weight becomes dominant, it becomes difficult to move the toner having moved to the both end portions into the developing container. Further, when the toner moved to the both ends is accumulated between the end of the toner carrier and the inner wall of the developing container, it is difficult to convey the accumulated toner into the developing container. When the amount of the toner is increased, the accumulated toner is scattered outside the developing device.

Therefore, in the developing device 5 according to this embodiment, in order to prevent the toner scattering, the toner carrier 5
The opening where b is located is provided in the upper part of the developing container 5a, that is, upward, and the toner is always present in the lower part of the developing container 5a opposite to the opening. With such a configuration of the developing container 5a, the toner that is about to be scattered from the opening is in a state of being easily collected in the developing container 5a by its own weight. In addition, the toner thin layer forming member 5
The toner that moves to both ends of the opening at d moves to the lower part in the developing container 5a by its own weight and is collected, so that the toner amount is prevented from increasing at both ends of the opening, that is, both ends of the toner carrier 5b. To be Therefore, it is possible to obtain a state in which toner scattering is less likely to occur.

In the developing device 5 according to this embodiment,
As shown in FIG. 1B, in order to further reliably prevent the toner moving to both ends of the opening by the toner thin layer forming member 5d from scattering from both ends of the opening, the opening of the developing container 5a is opened. A cover member 5g is provided to cover both ends of the toner carrier 5b exposed from the axial direction. For example, a film can be used as the cover member 5g, and the cover member 5g is used as the upper plate 5 of the developing container 5a.
The toner carrier 5b is fixed to the surfaces h and 5i in contact with the surface of the photoconductor 1 corresponding to the non-image portion. The width L in FIG. 1B indicates the image width, and the width a indicates the nip portion between the cover member 5g and the toner carrier 5b. In the nip portion a, the toner layer on the toner carrier 5b is separated from the surface of the photoconductor 1 due to the thickness of the cover member 5g, and a region where development cannot be performed occurs. The distance between the side edges is preferably slightly larger than the image width L.

Further, the cover member 5g may be fixed in a state in which the cover member 5g is not in contact with the toner carrying member 5b but is in close proximity thereto. In this configuration, if there is a step between the surface of the toner carrier 5b and the surface of the end portion of the cover member 5g, the distance between the end edges of the both cover members 5g on the side of the central portion of the photosensitive member 1 is set to be the photosensitive distance. It is desirable to make it longer than the length of the peripheral surface of the body 1 in the longitudinal direction.

The toner that has moved to both ends of the toner carrier 5b is in a state of being easily scattered by the centrifugal force due to the rotation of the toner carrier 5b. Most of the toner is dropped directly into the developing container 5a, and a part of the toner at both ends thereof passes through the nip portion a between the toner carrier 5b and the cover member 5g, thereby suppressing the toner scattering. it can. In this way, part of the toner is transferred to the nip portion a.
Therefore, it is desirable that the contact pressure of the cover member 5g at the nip portion a is set to be light so that the toner can pass therethrough.

Particularly, when the toner carrier 5b is composed of a soft surface such as an elastic body, the toner carrier 5b
At both ends of b, the pressure from the toner thin layer forming member 5d becomes small, the toner layer thickness at the both ends formed by the toner thin layer forming member 5d becomes thick, and toner scattering easily occurs, but the toner carrying is carried. By providing the opening where the body 5b is located in the upper portion of the developing container 5a, that is, upward, and by providing the cover member 5g, it is possible to reliably prevent toner scattering.

In the developing device 5 according to this embodiment,
Even when the opening for the toner carrier 5b is provided above the developing container 5a, that is, upward, the toner in the lower part of the developing container 5a can be reliably and stably supplied to the toner carrier 5b. A toner carrying means 13 is provided as a developer carrying means for carrying the toner existing in the lower part to the surface of the toner supply roller 5c.

FIG. 1A shows an example of the structure of the toner carrying means 13 provided inside the developing container 5a. The toner conveying means 13 serves as a toner feeding member 13a as a material feeding means, a toner receiving tray 13b as a material receiving member, and a toner moving path through which the toner contained in the lower portion of the developing container 5a moves upward. The toner transfer path 13c is configured by an agent transfer path forming means for forming the toner transfer path 13c. The agent movement path forming means is composed of a part of the inner wall surface of the developing container 5a and a plate-like member 13d having a surface substantially parallel to the inner wall surface, and the agent discharge path is formed at the end portion on the toner carrier 5b side. Toner outlet 1 as an outlet
The developing container 13a has a toner receiving port 13h as an agent receiving port at the lower end thereof.

The toner receiving tray 13b is, for example, a plate-like member provided at least partially in contact with or in proximity to the surface of the toner supply roller 5c and curved along the surface of the toner supply roller 5c. It is shown. The position where the toner receiving tray 13b approaches or contacts the toner supplying roller 5c is located on the upstream side in the rotation direction of the toner supplying roller 5c indicated by the arrow A4, that is, the toner conveyed to the toner receiving tray 13b by the toner moving path 13c enters. The side to be discharged is preferable to the side. In this case, the toner comes into contact with the toner supply roller 5c in a wider range and at a larger pressure, so that a large amount of toner can be supplied to the toner supply roller 5c.
The opening 13e on the side where the toner enters the tray 13b is provided so that the toner can easily enter.
Has a convenient gap with the surface of the toner supply roller 5c.

When the excessive toner is supplied to the toner receiving tray 13b, the excessive toner is supplied from the opening 13e on the side where the toner enters the toner receiving tray 13b or the opening 13f on the side where the toner is discharged as shown by arrows A5 and A6. In addition, it is designed to drop toward the lower part of the developing container 5a. That is, the openings 13e and 13f are drop ports for the excess toner conveyed to the toner receiving tray 13b. The agent dropping port may be an opening provided in the toner tray 13b,
The toner receiving tray 13b may be formed of a mesh screen having a large number of mesh-shaped agent dropping openings that do not cause excessive toner leakage.

The surface of the toner receiving tray 13b is
It is desirable that the toner has a roughened surface so that the toner does not easily drop. In addition, the toner on the toner tray 13b is
The toner receiving tray 13b is compacted between the toner receiving tray 13b and the toner supply roller 5c so that the toner receiving tray 13 does not cause image unevenness and insufficient image density.
It is desirable that b has elasticity, and metal or
A resin foam such as a thin plastic plate, rubber, sponge rubber, or urethane foam is a particularly preferable toner tray 1.
3b material.

The size of the gap between the plate-like member 13d and the inner wall surface of the developing container 5c forming the toner moving path 13c is preferably as small as possible within the range in which the toner can uniformly pass, and is preferably 0.2. ~ 5.0 mm. Further, the end portion of the toner moving path 13c prevents the toner from leaking from the end portion in the axial direction of the toner carrier 5b when the toner passes, and reduces the amount of toner conveyed near the end portion. It is desirable that both ends have a closed structure.

Further, the toner feeding member 13a is
It is formed in a shape convenient for surely feeding the toner to the toner receiving port 13h of the toner moving path 13c. In the example of FIG. 1A, a rotary conveyance member 13k is shown in which a plurality of elastic plates 13i as plate members are formed on a rotary shaft 13j. When the rotary conveyance member 13k rotates in the direction of arrow A7, the tip or abdomen of the elastic plate 13i is moved to the developing container 5
By moving close to or in contact with the bottom surface of a, almost all of the toner staying in the lower part of the developing container 5a can be sent into the toner moving path 13c.

Further, the elastic plate 1 of the rotary conveying member 13k.
3i is a toner receiving port 13 of the toner moving path 13c.
The toner 4 is provided so as to come into contact with the end portion 13l of the plate-shaped member 13d that forms h, and the toner fed by the elastic plate 13i of the rotary conveyance member 13k is scraped off by the end portion 13l, so that the toner 4 is carried. It can be fed more effectively toward the upper side where the body 5b is located.

The structure of the toner feeding member 13a is not limited to the example of the rotary conveying member 13k shown in FIG. 1 (a), and many other methods can be used. For example, it may be a rotary conveyance member in which a brush material is formed instead of the elastic plate 13i. Needless to say, the toner in the developing container 13a can be conveniently sent to the toner receiving port 13h without using the rotary conveying member.

Incidentally, in the developing device according to the above-mentioned embodiment, in order to seal both ends of the toner carrying member 5b, as shown in FIG.
You may provide the cover member 5j as shown in FIG. This cover member 5j prevents toner scattering more reliably,
Compared to the case of the developing device according to the embodiment of FIG. 1A, the developing device is provided at a larger angle with respect to the toner carrier 5b and extends to the inside of the developing container 5a. Also,
One end of the cover member 5j on the downstream side in the rotation direction of the toner carrier 5b is fixed to a fixing portion 5h inside the developing container 5a. The cover member 5j is formed of a thin film, and is a toner carrier 5b that carries and moves toner.
By making a small pressure contact with the surface of
The toner on the toner carrier 5b in the area in contact with the cover member 5j is reliably guided into the developing container 5a. In this case, as the convenient cover member 5j, a fluorine-containing polymer compound having a smooth surface, polyethylene, polypropylene,
Polymer films such as polyimide and nylon can be used.

Further, in the above-described embodiment, the developing device using the non-magnetic toner as the one-component developer and provided with the toner supply roller has been described. However, the present invention is not limited to the developing device without the toner supply roller. It can also be applied to a developing device using a toner and a developing device using a two-component developer. For example, as shown in FIG.
By providing the toner tray 13b so that the toner on the surface b is uniformly in contact with the toner carrier 5b, the toner supply roller is not necessarily required. In this case, a simpler developing device can be provided. In FIG. 4, the same parts as those in FIG. 3 are designated by the same reference numerals.

Further, in the cleaning device of the developing device 5 according to the above embodiment, the toner scraped from the photosensitive member 1 is conveyed to the toner collecting device (not shown) by the spiral member 11d, and is collected, as shown in FIG. The toner scraped off from the photoconductor 1 may be dropped into the developing container 5a by its own weight or the like and reused. In this case, since it is not necessary to provide a spiral member or the like, the size can be further reduced. In addition, in FIG.
The same parts as those in (a) are denoted by the same reference numerals.

In the above embodiment, the image forming section 10 is used.
The case where the present invention is applied to the developing device 5 of the full-color image forming apparatus including four sets of 0 has been described.
The number of the image forming units is not limited, and the present invention can be applied to, for example, a developing device in an image forming apparatus including only one image forming unit.

[0069]

According to the first to twelfth aspects of the present invention, it is sufficient to secure a space in which the developer can move as the agent moving path, and the agent feeding means is accommodated in the lower portion of the developing container. It is only necessary to feed the developed developer to the agent receiving port of the agent moving path provided in the vicinity thereof, and the shape of the agent feeding means can be made small. There is an effect that it is possible to further reduce the size and cost as compared with the case where a plurality of conveying members such as conveying rollers are arranged.

In particular, according to the second aspect of the invention, the developer on the surface of the agent receiving member is supplied so as to contact the developer carrying member or the intermediate agent carrying member substantially uniformly, so that the developer is received by the agent receiving member. Most of the developer can be used for development, and the developer in the developer container can be used without waste.

Further, according to the third aspect of the invention, when the developer receiving member receives the excessive developer, the excess developer falls into the developing container through the developer dropping port of the developer receiving member. Therefore, it is possible to prevent the pressure in the developer from rising due to the excessive developer and to prevent the developer from agglomerating, and the unevenness in the supply of the developer to the developer carrier and the unevenness in the image due to insufficient supply and the image density It is possible to prevent the decrease and to prevent the deterioration of the developer due to the increase of the pressure in the developer.

Further, in particular, according to the invention of claim 4, even when the amount of the developer received on the agent receiving member is partially excessive in the axial direction of the developer carrier, the amount of the developer is partially increased. Since the excess developer drops into the developing container through the developer drop port, it does not require a special developer amount control device,
A desired amount of the developer can be uniformly supplied in the axial direction to the developer carrier or the intermediate carrier, a desired image density can be obtained, and the uniformity of the image density in the axial direction can be improved. is there.

Further, in particular, according to the invention of claim 5, by roughening the surface of the developer receiving member, the developer receiving member can be received by vibration or frictional force generated when the developer carrying member or the intermediate carrying member is driven. Since the developer on the member does not fall into the developing container, there is an effect that it is possible to prevent the insufficient supply of the developer to the developer carrier.

Further, according to the invention of claim 6, even when a large amount of the developer is retained between the agent receiving member and the surface of the developer carrier or the surface of the intermediate carrier, the accumulated developer is Since the elastic developer receiving member is deformed so as not to receive an excessive pressure, it is possible to prevent the pressure in the developer from rising and to prevent the developer from agglomerating (blocking) to occur. It is possible to prevent image unevenness and decrease in image density due to uneven and insufficient supply of developer,
There is an effect that the deterioration of the developer due to the increase of the pressure in the developer can be prevented. (Hereinafter, margin)

Further, in particular, according to the invention of claim 7, the inner wall surface of the developing container is diverted as a part of the agent moving path forming means, and the inner wall surface and the inner wall surface are provided with a gap in which the developer can move. Since the agent moving path is formed by a simple combination of the plate-shaped members provided so as to face each other, there is an effect that it is possible to further reduce the size and cost of the developing device.

Further, according to the invention of claim 8, the gap between the facing surface of the plate-like member forming the agent moving path and the inner wall surface of the developing container is substantially constant in the axial direction of the developer carrying member. Thus, there is an effect that the amount of developer that is conveyed upward in the developer conveying path becomes uniform.

Further, in particular, according to the invention of claim 9, the plate-like member of the rotary transport member extending in the axial direction of the developer carrying member is provided below the developing container by the operation of rotating the rotary transport member. Since the stored developer is sent toward the agent receiving port of the agent moving path, the developer at the lower part of the developing container is reliably and uniformly conveyed and supplied onto the developer carrier through the agent moving path. There is an effect that can be done.

Further, in particular, according to the invention of claim 10, the plate-shaped member of the rotary transport member is provided when the rotary transport member is rotated to feed the developer toward the agent receiving port of the agent moving path.
When the developer adhering to the plate-shaped member comes into contact with or comes close to the edge of the agent transfer path forming means on the agent receiving side, the developer is scraped off by the edge and fed into the agent transfer path. There is an effect that the developer accommodated in the lower portion of the container can be more favorably fed into the agent movement path.

Further, in particular, according to the invention of claim 11, when the rotary conveying member is rotated and the developer is sent toward the agent receiving port of the agent moving path, it exists in a portion near the bottom surface of the developing container. Since the developer is scraped up and sent to the agent receiving port of the agent moving path, there is an effect that the developer existing in the lower portion of the developing container can be sent to the agent moving path more favorably.

Further, in particular, according to the invention of claim 12, when the plate-like member of the rotary conveying member comes into contact with or comes close to the edge of the above-mentioned agent movement path forming means, or comes into contact with or comes close to the bottom surface of the developing container. At this time, since the developer is deformed so that an excessive pressure is not applied, the pressure inside the developer is prevented from rising and aggregation of the developer is suppressed, and unevenness in supply of the developer to the developer carrier and It is possible to prevent the occurrence of image unevenness and the decrease in image density due to insufficient supply, and it is possible to prevent the deterioration of the developer due to the increase in the pressure inside the developer.

[Brief description of drawings]

FIG. 1A is a schematic configuration diagram of an image forming apparatus including a developing device according to an embodiment of the present invention. FIG. 6B is a perspective view of a cover member provided in the opening of the developing device.

FIG. 2 is a schematic configuration diagram of a full-color image forming apparatus including the developing device.

FIG. 3 is a schematic configuration diagram of a developing device according to a modification.

FIG. 4 is a schematic configuration diagram of a developing device according to another modification.

FIG. 5 is a schematic configuration diagram of a developing device according to still another modification.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging device 3 Exposure device 4 Toner 5 Developing device 5a Developing container 5b Toner carrier 5c Toner supply member 5d Toner thin layer forming member 5g Cover member 13 Toner conveying means 13a Toner feeding member 13b Toner tray 13c Toner moving path 13d Plate-shaped member 13g Toner discharge port 13h Toner receiving port 13i Elastic plate 13j Rotation shaft 13k Rotation conveyance member

Claims (12)

[Claims] 1. A developer carrying means for carrying a developer contained in a lower portion of a developing container to a developer carrying member partially exposed from an opening formed in an upper portion of the developing container, In a developing device for supplying the developer carried by the developer carrying means to the developer carrying body and developing the latent image on the latent image carrying body using the developer on the developer carrying body, An agent transfer path, which has an agent receiving port on the lower side of the developing container and an agent outlet on the developer carrier side, and forms an agent transfer path from the agent inlet to the agent outlet. A developing device comprising: a forming unit and an agent feeding unit that feeds a developer contained in a lower portion of the developing container to the agent receiving port. 2. The developing device according to claim 1, wherein a roller-shaped member is used as the developer carrier or an intermediate carrier for intermediately carrying a developer supplied to the developer carrier. An agent receiving member for receiving the developer discharged from the agent discharge port of the path forming means is provided in contact with or close to the surface of the developer carrying member or the surface of the intermediate agent carrying member, and the surface of the agent receiving member is the developing device. A developing device which is curved along the surface of the agent carrier or the surface of the intermediate agent carrier. 3. The developing device according to claim 1, further comprising an agent receiving member for receiving the developer discharged from the agent discharge port of the agent moving path forming means, wherein the agent receiving member holds the excess developer in the developing container. A developing device having an agent dropping port for dropping the inside. 4. The developing device according to claim 3, wherein the developer carrier or an intermediate carrier for intermediately carrying the developer to be supplied to the developer carrier has a movable surface. An agent receiving member for receiving the developer discharged from the agent discharge port of the agent transfer path forming means is provided, and the agent receiving member is provided with the agent dropping port in the moving direction of the surface of the developer carrier or the surface of the intermediate agent carrier. The developing device is provided on at least one of the downstream side and the upstream side of the developer carrier so as to extend in the axial direction of the developer carrying member. 5. The developing device according to claim 1, wherein an agent receiving member for receiving the developer discharged from the agent discharge port of the agent moving path forming means is provided, and the surface of the agent receiving member is roughened. Characteristic developing device. 6. The developing device according to claim 1, wherein an agent receiving member for receiving the developer discharged from the agent discharge port of the agent moving path forming means is supplied to the developer carrier or the developer carrier. A developing device, characterized in that it is provided in contact with or close to an intermediate agent carrying member for intermediately carrying a developer, and the agent receiving member has elasticity. 7. The developing device according to claim 1, wherein the agent movement path forming means is provided so as to face the inner wall surface of the developing container and the inner wall surface with a gap in which the developer can move. A developing device comprising: a member. 8. The developing device according to claim 7, wherein a surface of the plate-shaped member facing the inner wall surface is substantially parallel to the inner wall surface. 9. The developing device according to claim 1, wherein the developer feeding means is constituted by a rotary conveying member having a plate-like member extending in the axial direction of the developer carrying member formed on a rotary shaft. Developing device. 10. The developing device according to claim 9, wherein the plate-shaped member is in contact with or close to an edge of the agent moving path forming means on the agent receiving port side. 11. The developing device according to claim 9, wherein the plate-shaped member is in contact with or close to the bottom surface of the developing container. 12. The developing device according to claim 10, wherein the plate member has elasticity.