JP2019207332A5 - - Google Patents

Claims (19)

An image forming apparatus that forms a toner image on a recording material.
A rotatable image carrier, a charging member that contacts the image carrier to form a contact portion, and charges the image carrier at the contact portion, and the image charged by the charging member. An image having a first exposure means that exposes a carrier to form an electrostatic latent image, and a developing member that supplies toner to the electrostatic latent image to develop the toner image on the image carrier. Forming part and
A voltage applying means for applying a voltage to the charging member and
An intermediate transfer body that forms a transfer portion in contact with the image carrier and carries the toner image formed on the image carrier at the transfer portion.
A transfer member that transfers the toner image supported on the intermediate transfer body to a recording material, and
A second exposure means for exposing the image carrier on the downstream side of the transfer portion and on the upstream side of the contact portion in the rotation direction of the image carrier.
A control unit that controls the voltage applying means and the second exposure means,
In the image forming apparatus having
A first image forming mode in which the image carrier is rotated to form an image, and a second image forming mode in which the image carrier is rotated at a rotation speed higher than that of the first image forming mode to form an image. Is feasible and
In the control unit, the difference between the absolute value of the voltage applied to the voltage applying means and the absolute value of the surface potential of the image carrier exposed by the second exposure means is the difference between the first image formation. An image forming apparatus characterized in that the voltage applying means and the second exposure means are controlled so as to be larger when the second image forming mode is executed than when the mode is executed. The control unit controls so that the exposure amount for exposing the image carrier by the second exposure means is larger when the second image formation mode is executed than when the first image formation mode is executed. The image forming apparatus according to claim 1. The control unit is characterized in that the exposure by the second exposure means is controlled not to be executed when the first image forming mode is executed, but to be executed when the second image forming mode is executed. Or the image forming apparatus according to 2. The first exposure means exposes the image carrier charged by the charging member to form the surface potential that does not form the toner image, and forms the toner image. In order to form the surface potential, the image portion exposure is performed with an exposure amount larger than the exposure amount of the non-image portion exposure.
The control unit controls the exposure amount of the non-image portion exposure so that the surface potential of the image carrier that does not form the toner image becomes constant at the time of image formation. The image forming apparatus according to any one of claims 1 to 3, wherein the image forming apparatus is used. The control unit has an absolute value of the voltage applied to the voltage applying means of the image forming unit arranged in the most upstream direction in the rotation direction of the intermediate transfer body, and the image forming unit arranged in the most upstream flow. Control is performed so that the difference between the absolute value of the surface potential of the image carrier exposed by the second exposure means and the absolute value of the surface potential is the same in the first image forming mode and the second image forming mode. The image forming apparatus according to any one of claims 1 to 4, wherein the image forming apparatus is characterized in that. An image forming apparatus that forms a toner image on a recording material.
A rotatable image carrier, a charging member that contacts the image carrier to form a contact portion, and charges the image carrier at the contact portion, and the image charged by the charging member. An image forming unit having an exposure means for exposing a carrier to form an electrostatic latent image, and a developing member for supplying toner to the electrostatic latent image to develop the toner image on the image carrier. ,
A voltage applying means for applying a voltage to the charging member and
An intermediate transfer body that forms a transfer portion in contact with the image carrier and carries the toner image formed on the image carrier at the transfer portion.
A transfer member that transfers the toner image supported on the intermediate transfer body to a recording material, and
A control unit that controls the voltage applying means,
In the image forming apparatus having
A first image forming mode in which the image carrier is rotated to form an image, and a second image forming mode in which the image carrier is rotated at a rotation speed higher than that of the first image forming mode to form an image. Is feasible and
In the control unit, the difference between the absolute value of the voltage applied to the voltage applying means and the absolute value of the surface potential of the image carrier that plunges into the contact portion after passing through the transfer portion is determined. An image forming apparatus, characterized in that the voltage applying means is controlled so that the voltage applying means becomes larger when the second image forming mode is executed than when the first image forming mode is executed. Transferring the toner image to the intermediate transfer body by supplying an electric current from the contact member in contact with the outer peripheral surface or the inner peripheral surface of the intermediate transfer body to the image carrier via the intermediate transfer body. The image forming apparatus according to claim 6. 7. According to claim 7, the surface resistivity of the outer peripheral surface or the inner peripheral surface of the intermediate transfer body when 100 (V) is applied to the intermediate transfer body is 2 × 1010 (Ω / □) or less. The image forming apparatus according to the description. The exposure means applies a non-image portion exposure that exposes the image carrier charged by the charging member to form the surface potential that does not form the toner image, and the surface potential that forms the toner image. Image part exposure, which is exposed with an exposure amount larger than the exposure amount of the non-image part exposure for forming, is performed.
The control unit controls the exposure means to control the exposure amount of the non-image portion exposure so that the surface potential of the image carrier that does not form the toner image becomes constant at the time of image formation. The image forming apparatus according to any one of claims 6 to 8. The control unit has the absolute value of the voltage applied to the voltage applying means of the image forming unit arranged in the uppermost stream in the rotation direction of the intermediate transfer body, and the contact after passing through the transfer unit. It is characterized in that control is performed so that the difference between the absolute value of the surface potential of the image carrier that plunges into the portion and the absolute value of the surface potential is the same in the first image forming mode and the second image forming mode. The image forming apparatus according to any one of claims 6 to 9. An image forming apparatus that forms a toner image on a recording material.
With a rotatable image carrier,
A charging member that contacts the image carrier to form a contact portion and charges the image carrier at the contact portion.
A first exposure means for forming an electrostatic latent image by exposing the image carrier charged by the charging member,
A developing member that supplies toner to the electrostatic latent image and develops the toner image on the image carrier.
A voltage applying means for applying a voltage to the charging member and
A transfer member that transfers the toner image developed on the image carrier to a recording material at a transfer unit, and
A second exposure means for exposing the image carrier on the downstream side of the transfer portion and on the upstream side of the contact portion in the rotation direction of the image carrier.
A control unit that controls the voltage applying means and the second exposure means,
In the image forming apparatus having
A first image forming mode in which the image carrier is rotated to form an image, and a second image forming mode in which the image carrier is rotated at a rotation speed higher than that of the first image forming mode to form an image. Is feasible and
In the control unit, the difference between the absolute value of the voltage applied to the voltage applying means and the absolute value of the surface potential of the image carrier exposed by the second exposure means is the difference between the first image formation. An image forming apparatus characterized in that the voltage applying means and the second exposure means are controlled so as to be larger when the second image forming mode is executed than when the mode is executed. The control unit controls so that the exposure amount for exposing the image carrier by the second exposure means is larger when the second image formation mode is executed than when the first image formation mode is executed. The image forming apparatus according to claim 11. 11. The control unit is characterized in that the exposure by the second exposure means is controlled not to be executed when the first image forming mode is executed, but to be executed when the second image forming mode is executed. Or the image forming apparatus according to 12. The first exposure means exposes the image carrier charged by the charging member to form the surface potential that does not form the toner image, and forms the toner image. In order to form the surface potential, the image portion exposure is performed with an exposure amount larger than the exposure amount of the non-image portion exposure.
The control unit controls the exposure amount of the non-image portion exposure so that the surface potential of the image carrier that does not form the toner image becomes constant at the time of image formation. The image forming apparatus according to any one of claims 11 to 13, wherein the image forming apparatus is controlled. An image forming apparatus that forms a toner image on a recording material.
With a rotatable image carrier,
A charging member that contacts the image carrier to form a contact portion and charges the image carrier at the contact portion.
An exposure means for exposing the image carrier charged by the charging member, and
A developing member that supplies toner to the image carrier exposed by the exposure means and develops the toner image on the image carrier.
A voltage applying means for applying a voltage to the charging member and
A transfer member that transfers the toner image developed on the image carrier to a recording material at a transfer unit, and
A control unit that controls the voltage applying means,
In the image forming apparatus having
A first image forming mode in which the image carrier is rotated to form an image, and a second image forming mode in which the image carrier is rotated at a rotation speed higher than that of the first image forming mode to form an image. Is feasible and
In the control unit, the difference between the absolute value of the voltage applied to the voltage applying means and the absolute value of the surface potential of the image carrier that plunges into the contact portion after passing through the transfer portion is determined. An image forming apparatus, characterized in that the voltage applying means is controlled so that the voltage applying means becomes larger when the second image forming mode is executed than when the first image forming mode is executed. The exposure means applies a non-image portion exposure that exposes the image carrier charged by the charging member to form the surface potential that does not form the toner image, and the surface potential that forms the toner image. Image part exposure, which is exposed with an exposure amount larger than the exposure amount of the non-image part exposure for forming, is performed.
The control unit controls the exposure means to control the exposure amount of the non-image portion exposure so that the surface potential of the image carrier that does not form the toner image becomes constant at the time of image formation. The image forming apparatus according to claim 15. The control unit controls the voltage applied to the charging member by the voltage applying means so that the absolute value becomes larger when the second image forming mode is executed than when the first image forming mode is executed. The image forming apparatus according to any one of claims 1 to 16. When either the first image forming mode or the second image forming mode is executed, the developing member recovers the residual toner that is not used for image forming and remains on the image carrier. The image forming apparatus according to any one of claims 1 to 17, wherein the image forming apparatus is characterized. The image forming apparatus according to any one of claims 1 to 18, wherein the toner is a one-component developer.