JP2001249539A - Developing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the surface of an image carrier from being scratched by a side seal and further to prevent an abnormal image from being formed by the faulty electrification of the image carrier in an image forming device using an electrifying device equipped with a member for electrification coming into contact with the image carrier. SOLUTION: This developing device is equipped with a developing case 14 having an aperture part on a side opposed to a photoreceptor 1, a developing roller 11 arranged in the aperture part of the case 14, and the side seal 15 covering the peripheral surfaces of both ends in the shaft direction of the roller 11 in the aperture part of the case 14. And, the end of the side seal is inclined to the shaft of the developing roller and brought into contact with the photoreceptor obliquely, whereby stress exerted on the periphery of the photoreceptor by the end of the side seal is dispersed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile, a printer, and the like, and a developing device employed therein.

[0002]

2. Description of the Related Art In a developing device employed in the above-described image forming apparatus, an opening is formed on a side of a developing case facing an image carrier, and a developer carrier is disposed in the opening. The developer carrier carries the developer stored in the developing device by rotation, and conveys the developer to a developing position where the developer carrier and the image carrier in the opening face each other. Here, in order to prevent the developer from being scattered from the end of the developer carrier at the opening of the developing case, side seals are provided to cover the peripheral surfaces of both ends in the axial direction of the developer carrier at the opening of the developing case. Are widely known. Also, in order to further reduce the scattering of the developer,
It has been proposed to use a breathable sheet for the material of the side seal (see, for example, Japanese Patent Application Laid-Open No. 5-119626).

[0003]

Incidentally, the above-mentioned side seal is used in a state of being in contact with the opposed image carrier. The end of the side seal is on the same circumference of the developer carrier as shown in FIG. Therefore, when the image carrier rotates, the end of the side seal is
It is always in contact with the same circumference of the image carrier, and excessive stress is applied to the same circumference of the image carrier. This stress causes a problem that linear scratches are generated on the surface of the image carrier. FIG. 5 shows a state in which a linear scratch has occurred on the surface of the image carrier due to the contact between the end of the side seal and the image carrier.

Further, toner adheres to scratches on the surface of the image bearing member.
It is difficult to remove the toner attached to the scratch from the image carrier. For this reason, when the charging device for forming the electrostatic latent image on the image carrier has a charging member such as a charging roller that comes into contact with the image carrier, the charging device adheres to the scratch on the surface of the image carrier. The toner adheres to the charging member and deteriorates the charging member. Of course, since the portion of the image carrier facing the side seal is outside the image forming area, no problem occurs on the image initially. However, as the image forming cycle is repeated, the toner attached to the end of the charging member spreads to the center, and eventually reaches the image area. That is, the deterioration of the charging member reaches the image forming area, and the image carrier causes poor charging in the image forming area. Such a charging failure causes an edge image stain in an image forming apparatus by reversal development, and an abnormal image of insufficient image density in an image forming apparatus by regular development.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a first object of the present invention is to provide a developing device and an image forming apparatus for preventing a surface seal from being damaged by a side seal. That is. Further, a second object is to provide an image forming apparatus using a charging device having a charging member that comes into contact with the image carrier, wherein an image forming apparatus that prevents abnormal image generation due to charging failure of the image carrier is provided. To provide.

[0006]

According to a first aspect of the present invention, there is provided a developing case having an opening on a side facing an image bearing member, and a developing case having an opening at the developing case opening. And a side seal that covers the peripheral surfaces of both ends of the developer case in the axial direction of the developing case opening, wherein the end of the side seal is attached to the shaft of the developer case. It is characterized by being inclined with respect to this.

According to the first aspect of the present invention, since the end of the side seal is inclined with respect to the axis of the developing carrier, the end of the side seal comes into oblique contact with the image carrier. The stress that the end of the side seal exerts on the periphery of the image carrier is dispersed. Therefore, the risk of damaging the surface of the image carrier is reduced.

According to a second aspect of the present invention, there is provided a developing case having an opening on a side opposed to an image carrier, a developer carrying member disposed at the opening of the developing case, and a developing device for developing the opening of the developing case. A side seal that covers the peripheral surfaces of both ends of the developer carrier in the axial direction, wherein the side end of the side seal in the axial direction of the developer carrier is inclined with respect to the axis of the developer carrier. It is characterized by the following.

In the second aspect of the present invention, since the end of the side seal at the center of the developer carrier is inclined with respect to the axis of the developer carrier, the end of the side seal at the center of the developer carrier is provided. Comes into oblique contact with the image carrier, and the stress applied to the periphery of the image carrier by the end of the side seal at the center of the developer carrier is dispersed. Therefore, the possibility of damaging the surface of the image carrier near the image forming area can be reduced.

When the end of the side seal at the center of the developer carrier is inclined toward the center of the developer carrier from the upstream side to the downstream side in the rotation direction of the developer carrier, The developer transported with the rotation of the developer carrier is
It gets on the side seal on the downstream side. And
The developer running on the side seal scatters inside the machine.

According to a third aspect of the present invention, in the second aspect of the present invention, the center end of the side seal in the axial direction of the developer carrying member extends from the upstream side to the downstream side in the rotational direction of the developer carrying body. And is inclined toward the end of the developer carrying member.

In the developing device according to the third aspect, the end of the side seal at the center in the axial direction of the developer carrying member extends from the upstream side to the downstream side in the rotation direction of the developer carrying body. , The developer transported along with the rotation of the developer carrier is collected into the developing device without running on the side seal. For this reason, it is possible to prevent the developer from scattering into the machine.

According to a fourth aspect of the present invention, in the developing device according to the third aspect, the inclination angle of the side end of the side seal at the central side in the axial direction of the developer carrier is set with respect to the axis of the developer carrier. It is characterized by being at least 5 °.

In the image forming apparatus according to the present invention, if the end of the side seal at the center in the axial direction of the developer carrying member has an inclination of 5 ° or more with respect to the axis of the developer carrying body, the side seal is provided with the side seal. Experiments have shown that the effect of preventing the vehicle from climbing up is great.

According to a fifth aspect of the present invention, there is provided an image bearing member, a charging device for forming an electrostatic latent image on the image bearing member, and an electrostatic latent image on the image bearing member is visible with a developer. An image forming apparatus provided with a developing device for forming an image, wherein the developing device according to claim 1, 2, 3, or 4 is used as the developing device.

In the image forming apparatus according to the fifth aspect, by using the developing device, the stress applied to the end of the side seal on the image carrier can be dispersed, and the possibility of damaging the surface of the image carrier can be reduced. be able to.

Further, in order to achieve the second object,
According to a sixth aspect of the present invention, in the image forming apparatus of the fifth aspect,
An image forming apparatus, wherein the charging device includes a charging member that contacts the image carrier.

According to a sixth aspect of the present invention, in the image forming apparatus using a charging device provided with a charging member that comes into contact with the image carrier, the toner adhered to the scratch of the image carrier is charged to the charging member. Adhesion and deterioration of the charging member can be prevented. For this reason, it is possible to prevent the occurrence of an abnormal image due to poor charging of the image carrier.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an image forming apparatus such as a copying machine, a facsimile, a printer and the like will be described below. FIG. 1 is a schematic configuration diagram of a main part of the image forming apparatus according to the present embodiment. The image forming apparatus shown in FIG. 1 includes a photoconductor 1 around a photoconductor 1 as an image carrier.
A charging device provided with a charging roller 2 as a charging member that comes into contact with the surface of the photoconductor 1; an exposure device 3 that irradiates the photoconductor 1 with a laser beam or the like to form an electrostatic latent image; A developing device 4 for forming a toner image by attaching charged toner to the image; a transfer roller 5 as a transfer device for transferring the toner image formed on the photoreceptor 1 to a transfer paper as a transfer member; A cleaning device 6 for removing the toner remaining on the photoreceptor 1 and a charge removing device 7 for removing the residual potential on the photoreceptor 1 are arranged in this order. Further, a paper feeder (not shown) that feeds the transfer paper from a paper feed tray (not shown), and a fixing device (not shown) that fixes the toner to the transfer paper after the transfer paper on which the toner image has been transferred is separated from the photoconductor 1. And are provided.

In the image forming apparatus configured as described above, the surface of the photoreceptor 1 rotating in the direction of arrow a is uniformly charged by the charging roller 2, and then the laser beam of the exposure device 3 is irradiated based on the image information. Irradiation forms a latent image on the photoreceptor 1. A toner image is formed by attaching toner charged by the developing device 4 to the electrostatic latent image formed on the photoconductor 1. On the other hand, the transfer sheet is fed from a sheet feed tray by a sheet feeder (not shown), and then transferred to a transfer unit where the photoconductor 1 and the transfer roller 5 are opposed to each other. Then, the transfer roller 5 applies a charge having a polarity opposite to that of the toner image on the photoconductor 1 to the transfer paper, thereby transferring the toner image formed on the photoconductor 1 to the transfer paper. Next, the transfer paper is separated from the photoreceptor 1, sent to a fixing device (not shown), and an image is obtained by fixing the toner to the transfer paper.

Next, the developing device 4 employed in the image forming apparatus will be described in detail. FIG. 2 is a perspective view showing a schematic configuration of the developing device. It comprises a developing roller 11 as a developer carrier, a supply roller 12 for supplying a developer to the developing roller 11, a developer accommodating chamber 13 for accommodating a toner as a developer, a developing case 14, and the like. The developing case 14 has an opening on the side facing the photoconductor 1. The developing roller 11 is disposed at the opening of the developing case 14, and the developing roller 11 is
And the photoconductor 1 face each other. The toner in the developer accommodating chamber 13 is supplied onto the developing roller 11 by the supply roller 12. The developing roller 11 carries the toner and transports the toner to a developing position where the developing roller 11 and the photoconductor 1 face each other.

In the developing device 4, in order to prevent toner from scattering from the end of the developing roller 11 at the opening of the developing case 14, the developing roller 11 at the opening of the developing case 14 is formed.
Side seals 15 are provided to cover the peripheral surfaces at both ends. Of course, the position of the side seal 15 is outside the image forming area. The end of the side seal 15 at the center of the developing roller 11 is inclined with respect to the axis of the developing roller 11. For this reason, the end of the side seal 15 on the central side of the developing roller 11 comes into oblique contact with the photoconductor 1, and the stress applied to the end of the side seal 15 on the photoconductor 1 is dispersed. Therefore, the possibility of damaging the surface of the photoconductor 1 is reduced.

If the end of the side seal 15 at the center of the developing roller 11 is inclined toward the center of the developing roller 11 from the upstream side to the downstream side in the rotation direction of the developing roller 11, the developing roller The toner conveyed with the rotation of 11 runs on the side seal 15 on the downstream side. Then, the toner running on the side seal 15 is scattered in the apparatus.

Therefore, as shown in FIGS. 3 and 4, the end of the side seal 15 is inclined from the upstream side to the downstream side in the rotation direction of the developing roller 11 toward the developing roller end. I do. FIG. 3 is a perspective view showing the shape of the side seal 15 with respect to the developing roller 11. FIG. 4 is a front view showing the shape of the side seal 15. With such a shape, the toner conveyed with the rotation of the developing roller 11 is collected into the developing device 4 without running on the side seal 15. Therefore, it is possible to prevent the toner from scattering in the apparatus.

Experimentally, in the developing device 4 having the above configuration, the rotation angle of the developing roller 11 is set to 230 mm / sec, and the inclination angle of the end of the side seal 15 at the center of the developing roller 11 is adjusted to the axis of the developing roller 11. On the other hand, when the angle was 5 ° or more, it was found that the effect of preventing the toner conveyed along with the rotation of the developing roller 11 from running on the side seal 15 was great.

Incidentally, in the image forming apparatus of this embodiment, the charging device includes the charging roller 2 which is a charging member that comes into contact with the image carrier. In such an image forming apparatus, the scratches on the photoreceptor 1 adversely affect the charging member. If the photoconductor 1 has a flaw, toner adheres to the flaw. However, it is difficult for the cleaning device 6 to remove the toner adhering to the flaw from the photoconductor 1. For this reason, the toner that has adhered to the scratches on the photoconductor 1 adheres to the charging roller 2 and deteriorates the charging function. Of course, since the portion of the photoconductor 1 facing the side seal 15 of the developing device 4 is outside the image forming area, no problem occurs on the image initially. However, as the image forming cycle is repeated, the toner attached to the end of the charging roller 2 spreads to the center side, and eventually reaches the image area. That is, the deterioration of the charging roller 2 reaches the image forming area,
The photoreceptor 1 causes poor charging in the image forming area. Such a charging failure causes an edge image stain in an image forming apparatus by reversal development, and an abnormal image of insufficient image density in an image forming apparatus by regular development.

However, in the image forming apparatus of the present embodiment, the side seal 15 of the developing device 4 is inclined with respect to the axis of the developing roller. It is possible to prevent the function from deteriorating. Therefore, there is little possibility that an abnormal image is generated.

As described above, in the image forming apparatus according to the present embodiment, the end of the side seal 15 of the developing device 4 on the central side of the developing roller 11 is inclined with respect to the axis of the developing roller, so that a portion near the image forming area is exposed. Prevents scratches on the body 1 and forms a good image. Further, by inclining the end of the side seal at the end of the developing roller 11 with respect to the axis of the developing roller, it is possible to prevent the photosensitive member 1 from being damaged over the entire axial direction of the photosensitive member 1.

Although the present invention has been described using an image forming apparatus employing a developing device using toner as a developer, the present invention is also applicable to an image forming apparatus employing a developing device using a two-component developer. Yes, a similar effect can be obtained.

[0030]

According to the first to sixth aspects of the present invention, there is an excellent effect that it is possible to provide a developing device and an image forming apparatus which prevent the surface of the image carrier from being damaged by the side seal.

In particular, according to the second aspect of the invention, there is an excellent effect that it is possible to prevent the occurrence of scratches on the surface of the image carrier near the image forming area.

In particular, according to the invention of claim 3 or 4,
There is an excellent effect that the developer can be prevented from running on the side seal of the developing device, and the developer can be prevented from being scattered in the apparatus.

Further, according to the present invention, in an image forming apparatus using a charging device having a charging member which comes into contact with an image carrier, an image for preventing occurrence of an abnormal image due to poor charging of the image carrier is provided. There is an excellent effect that a forming apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment.

FIG. 2 is a perspective view illustrating a schematic configuration of a developing device employed in the image forming apparatus.

FIG. 3 is a perspective view showing a shape of a side seal of the developing device.

FIG. 4 is a front view showing the shape of a side seal of the developing device.

FIG. 5 is a perspective view showing the shape of a side seal in a conventional developing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging roller 3 Exposure device 4 Developing device 5 Transfer roller 6 Cleaning device 7 Static eliminator 11 Developing roller 12 Supply roller 13 Developer storage chamber 14 Developing case 15 Side seal

Continued on the front page (72) Inventor Akira Sawada 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (Reference) 2H003 AA01 BB11 CC05 2H077 AC16 AD02 AD06 AD12 CA12 EA15 GA17

Claims (6)

[Claims] A developing case having an opening on a side facing the image carrier; a developer carrying member disposed in the developing case opening; and both ends of the developing case opening in the axial direction of the developer carrying member. A developing device comprising: a side seal that covers a peripheral surface, wherein an end of the side seal is inclined with respect to an axis of a developer carrier. 2. A developing case having an opening on a side facing the image carrier, a developer carrying member disposed in the developing case opening, and both ends of the developing case opening in the axial direction of the developer carrying member. A developing device comprising: a side seal that covers a peripheral surface, wherein a side end of the side seal in the axial direction of the developer carrier is inclined with respect to an axis of the developer carrier. 3. The developing device according to claim 2, wherein the end of the side seal in the axial center of the developer carrying member extends from the upstream side to the downstream side in the rotation direction of the developer carrying body. A developing device characterized by being inclined toward an end. 4. The developing device according to claim 3, wherein the inclination angle of the end of the side seal at the center in the axial direction of the developer carrier is:
A developing device characterized by being at an angle of 5 ° or more with respect to the axis of the developer carrier. 5. An image carrier, a charging device for forming an electrostatic latent image on the image carrier, and a developing device for developing the electrostatic latent image on the image carrier with a developer. An image forming apparatus according to claim 1, wherein the developing device according to claim 1, 2, 3, or 4 is used as the developing device. 6. An image forming apparatus according to claim 5, wherein said charging device includes a charging member for contacting the image carrier.