JP3893235B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a copying machine, a facsimile, in which relates to an image forming equipment such as a printer.
[0002]
[Prior art]
In the developing device employed in the image forming apparatus, an opening is formed on the side of the developing case facing the image carrier, and the 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 development position where the developer carrier and the image carrier in the opening face each other. Here, in order to prevent the developer from scattering from the end of the developer carrying member 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 carrying member at the developing case opening. Are widely known. Further, in order to further reduce the scattering of the developer, a proposal has been made such that the material of the side seal is a breathable sheet (see, for example, JP-A-5-119626).
[0003]
[Problems to be solved by the invention]
By the way, the side seal is used in a state in which it is in contact with an opposing image carrier. Further, the end portion of the side seal is on the same circumference of the developer carrier as shown in FIG. For this reason, when the image carrier is rotated, the end of the side seal 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. Due to this stress, there is a problem that a linear flaw is generated on the surface of the image carrier. FIG. 5 shows a state in which linear scratches are generated on the surface of the image carrier due to the contact between the side seal end and the image carrier.
[0004]
Further, although toner adheres to the scratch on the surface of the image carrier, it is difficult for the cleaning device of the image forming apparatus to remove the toner attached to the scratch from the image carrier. For this reason, when the charging device for forming an electrostatic latent image on the image carrier has a charging member that comes into contact with the image carrier such as a charging roller, it adheres to the scratches 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 that faces the side seal is outside the image forming area, no image problems occur initially. However, as the image forming cycle is repeated, the toner adhering to the end of the charging member spreads to the center side and eventually reaches the image area. That is, the deterioration of the charging member reaches the image forming area, and the image carrier causes a charging failure in the image forming area. Such a charging failure causes an end image smear in an image forming apparatus using reversal development, and an abnormal image in which an image density is insufficient in an image forming apparatus using regular development.
[0005]
The present invention has been made in view of the above problems, the first place of interest is to provide the images forming apparatus that to prevent scratches of the image bearing member surface by the side seals. Further, a second object is to provide an image forming apparatus using a charging device including a charging member that contacts the image carrier, and preventing an abnormal image from being generated due to poor charging of the image carrier. Is to provide.
[0006]
[Means for Solving the Problems]
In order to achieve the first object, an invention according to claim 1 is directed to an image carrier, a charging device for forming an electrostatic latent image on the image carrier, and an electrostatic latent image on the image carrier. An image forming apparatus including a developing device that develops an image with a developer. The developing device is disposed in a developing case having an opening on a side facing the image carrier, and the developing case opening. a developer carrying member, and a side seal for covering the developer carrying member axial end portions the peripheral surface of the developing casing opening in contact with the image bearing member, an end portion of the side seal developer Inclined with respect to the axis of the carrier.
[0007]
In the image forming apparatus according to claim 1, since the end portion of the side seal is inclined with respect to the axis of the developing carrier, the side seal end portion comes into contact with the image carrier obliquely, The stress applied to the periphery of the image carrier by the seal end is dispersed. For this reason, the risk of damaging the surface of the image carrier is reduced.
[0008]
According to a second aspect of the present invention, there is provided an image carrier, a charging device for forming an electrostatic latent image on the image carrier, and development for developing the electrostatic latent image on the image carrier with a developer. In the image forming apparatus, the developing device includes a developing case having an opening on a side facing the image carrier, a developer carrier disposed in the developing case opening, and the image carrier. and a side seal in contact with the body covering the developer carrying member axial end portions the peripheral surface of the developing casing opening, the developer carrying member axial center side ends of the side seal developer carrying Inclined with respect to the axis of the body.
[0009]
In the image forming apparatus according to claim 2, since the end portion of the side seal on the developer carrier is inclined with respect to the axis of the developer carrier, the end portion of the side seal on the developer carrier is an image. It comes into contact with the carrier at an angle, and the stress applied to the periphery of the image carrier by the developer carrier central end of the side seal is dispersed. Therefore, the risk of scratching the surface of the image carrier near the image forming area can be reduced.
[0010]
By the way, the developer carrying member central side end of the side seal is inclined toward the developer carrying member central side from the upstream side to the downstream side in the rotation direction of the developer carrying member. The developer conveyed along with the rotation of the body runs on the side seal on the downstream side. Then, the developer riding on the side seal is scattered in the machine.
[0011]
Accordingly, the invention of claim 3 is the invention of claim 2, wherein the developer carrying member axially central end of the side seal is developed from the upstream side to the downstream side in the rotation direction of the developer carrying member. Inclined toward the end of the agent carrier.
[0012]
According to another aspect of the image forming apparatus of the present invention , the central end of the side seal in the developer carrying body axial direction is directed from the upstream side to the downstream side in the rotation direction of the developer carrying body toward the end of the developer carrying body. Because of the shape, the developer conveyed along with the rotation of the developer carrying member is collected into the developing device without running on the side seal. For this reason, it is possible to prevent the developer from scattering in the apparatus.
[0013]
According to a fourth aspect of the present invention , there is provided the image forming apparatus according to the third aspect, wherein the inclination angle of the side end of the side seal in the axial direction of the developer carrier is 5 with respect to the axis of the developer carrier. It is characterized by being at least °.
[0014]
5. The image forming apparatus according to claim 4, wherein the developer runs on the side seal when the end of the side seal in the axial direction of the developer carrier has an inclination of 5 ° or more with respect to the axis of the developer carrier. Experiments have shown that there is a great effect of preventing it.
[0017]
In order to achieve the second object, the invention of claim 5 is the image forming apparatus according to claim 1, 2, 3 or 4, comprising a charging member for the charging device contacts the image bearing member It is characterized by that .
[0018]
In the image forming apparatus according to claim 6, in the image forming apparatus using the charging device including the charging member that contacts the image carrier, the toner attached to the scratch on the image carrier adheres to the charging member. It is possible to prevent the charging member from being deteriorated. For this reason, it is possible to prevent the occurrence of abnormal images due to poor charging of the image carrier.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to an image forming apparatus such as a copying machine, a facsimile, or a printer will be described.
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 charging device provided with a charging roller 2 as a charging member in contact with the surface of the photosensitive member 1 around the photosensitive member 1 as an image carrier, and a laser beam to the photosensitive member 1. An exposure device 3 that forms an electrostatic latent image by irradiation, a developing device 4 that forms a toner image by attaching a charged toner to the electrostatic latent image formed on the photosensitive member 1, and formed on the photosensitive member 1 A transfer roller 5 as a transfer device that transfers the toner image to a transfer sheet as a transfer member, a cleaning device 6 that removes toner remaining on the photosensitive member 1 after transfer, and a static elimination that removes residual potential on the photosensitive member 1 The device 7 is arranged in order. In addition, a paper feeding / conveying device (not shown) that feeds transfer paper from a paper feeding tray (not shown), and a fixing device (not shown) that fixes the toner onto the transfer paper after the transfer paper on which the toner image has been transferred are separated from the photoreceptor 1. And are provided.
[0020]
In the image forming apparatus configured as described above, the surface of the photoreceptor 1 rotating in the direction of the arrow a is uniformly charged by the charging roller 2 and then irradiated with the laser beam or the like of the exposure device 3 based on the image information. A latent image is formed 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 photoreceptor 1. On the other hand, the transfer paper is fed from a paper feed tray by a paper feed / conveying device (not shown), and then conveyed to a transfer portion where the photosensitive member 1 and the transfer roller 5 face each other. 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 photoconductor 1, sent to a fixing device (not shown), and an image is obtained by fixing the toner to the transfer paper.
[0021]
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. A developing roller 11 as a developer carrying member, a supply roller 12 for supplying a developer to the developing roller 11, a developer accommodating chamber 13 for accommodating toner as a developer, a developing case 14 and the like. The developing case 14 has an opening on the side facing the photoreceptor 1. The developing roller 11 is disposed in the opening of the developing case 14, and the developing roller 11 and the photosensitive member 1 face each other through the opening. The toner in the developer storage chamber 13 is supplied onto the developing roller 11 by the supply roller 12. The developing roller 11 carries toner and conveys the toner to a developing position where the developing roller 11 and the photosensitive member 1 face each other.
[0022]
In the developing device 4, side seals 15 that cover the peripheral surfaces of both ends of the developing roller 11 in the opening of the developing case 14 are provided in order to prevent toner from scattering from the end of the developing roller 11 in the opening of the developing case 14. ing. Of course, the position of the side seal 15 is outside the image forming area. The end of the side seal 15 on the center side 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 center side of the developing roller 11 comes into contact with the photoreceptor 1 at an angle, and the stress applied to the end of the side seal 15 on the photoreceptor 1 is dispersed. For this reason, the risk of damaging the surface of the photoreceptor 1 is reduced.
[0023]
By the way, if the end of the side seal 15 on the center side of the developing roller 11 is inclined from the upstream side to the downstream side in the rotation direction of the developing roller 11 toward the central side of the developing roller 11, the rotation of the developing roller 11 is performed. As a result, the conveyed toner runs on the side seal 15 on the downstream side. Then, the toner riding on the side seal 15 is scattered in the machine.
[0024]
Therefore, as shown in FIGS. 3 and 4, the end portion of the side seal 15 is inclined toward the developing roller end portion from the upstream side to the downstream side in the rotation direction of the developing roller 11. 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. By adopting such a shape, the toner conveyed along 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.
[0025]
Experimentally, in the developing device 4 configured as described above, the rotation speed of the developing roller 11 is 230 mm / sec, and the inclination angle of the end of the side seal 15 on the center side of the developing roller 11 is 5 with respect to the axis of the developing roller 11. It has been found that when the angle is not less than 0 °, the effect of preventing the toner conveyed along the rotation of the developing roller 11 from running on the side seal 15 is great.
[0026]
Incidentally, in the image forming apparatus of the present embodiment, the charging device includes the charging roller 2 that is a charging member that contacts the image carrier. In such an image forming apparatus, scratches on the photosensitive member 1 adversely affect the charging member. If the photosensitive member 1 is scratched, toner adheres to the scratch, but it is difficult for the cleaning device 6 to remove the toner attached to the scratch from the photosensitive member 1. For this reason, the toner adhering to the scratches of the photoreceptor 1 adheres to the charging roller 2 and deteriorates the charging function. Of course, the portion of the photosensitive member 1 that faces the side seal 15 of the developing device 4 is outside the image forming area, so that no problem is caused on the image at the beginning. However, as the image forming cycle is repeated, the toner adhering 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, and the photosensitive member 1 causes a charging failure in the image forming area. Such a charging failure causes an end image smear in an image forming apparatus using reversal development, and an abnormal image in which an image density is insufficient in an image forming apparatus using regular development.
[0027]
However, in the image forming apparatus of the present embodiment, since the side seal 15 of the developing device 4 is inclined with respect to the axis of the developing roller, there is little possibility of damaging the surface of the photoreceptor 1 and the charging function of the charging roller 2 is deteriorated. It is possible to prevent this from happening. For this reason, there is little possibility that an abnormal image will be generated.
[0028]
As described above, in the image forming apparatus according to the present embodiment, the central end of the developing roller 11 of the side seal 15 of the developing device 4 is inclined with respect to the axis of the developing roller, so that the portion of the photoreceptor 1 near the image forming area is formed. Scratches are prevented and good image formation is performed. Further, the end of the side seal on the end side of the developing roller 11 is inclined with respect to the axis of the developing roller, whereby scratches on the photosensitive member 1 can be prevented over the entire axial direction of the photosensitive member 1.
[0029]
As described above, the present invention has been described using an image forming apparatus that employs a developing device that uses toner as a developer. However, the present invention can also be applied to an image forming apparatus that employs a developing device that uses a two-component developer. The effect is obtained.
[0030]
【The invention's effect】
According to the invention of claims 1 to 5, there is an excellent effect that it is possible to provide the images forming apparatus that to prevent scratches of the image bearing member surface by the side seals.
[0031]
In particular, according to the invention of claim 2, 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.
[0032]
In particular, according to the third or fourth aspect of the invention, there is an excellent effect that the developer can be prevented from riding on the side seal of the developing device and the developer can be prevented from scattering into the apparatus.
[0033]
According to a fifth aspect of the present invention, there is provided an image forming apparatus using a charging device including a charging member that contacts the image carrier, wherein the image forming apparatus prevents an abnormal image from being caused by a charging failure of the image carrier. There is an excellent effect that it 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 showing 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 apparatus 4 Development apparatus 5 Transfer roller 6 Cleaning apparatus 7 Static elimination apparatus 11 Development roller 12 Supply roller 13 Developer storage chamber 14 Development case 15 Side seal

Claims (5)

An image forming apparatus comprising: 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. ,
The developing device includes a developing case having an opening on the side facing the image carrier, a developer carrier disposed in the developing case opening, and the developing case opening in contact with the image carrier. and a side seal for covering the developer carrying member axial end portions the peripheral surface of the part,
An image forming apparatus, wherein an end of the side seal is inclined with respect to an axis of a developer carrying member. An image forming apparatus comprising: 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. ,
The developing device includes a developing case having an opening on the side facing the image carrier, a developer carrier disposed in the developing case opening, and the developing case opening in contact with the image carrier. and a side seal for covering the developer carrying member axial end portions the peripheral surface of the part,
An image forming apparatus, wherein the side end of the side seal in the developer carrying member axial direction is inclined with respect to the axis of the developer carrying member. The image forming apparatus according to claim 2.
The developer carrying member axially central end of the side seal is inclined toward the developer carrying member end from the upstream side to the downstream side in the rotation direction of the developer carrying member. Image forming apparatus . The image forming apparatus according to claim 3.
2. An image forming apparatus according to claim 1, wherein an inclination angle of a side end of the side seal in the developer carrying member axial direction is 5 ° or more with respect to the axis of the developer carrying member . The image forming apparatus 請 Motomeko 1, 2, 3 or 4,
An image forming apparatus, wherein the charging device includes a charging member that contacts an image carrier.

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