Abstract: A hydro dynamic bearing device comprising an upper half of a main bearing and a lower half of the main bearing, wherein the upper half of the main bearing is lined with a low-strength metal such as a Babbitt metal, wherein a circumferential groove is formed in the lower half of the main bearing, and wherein the low-strength metal of the upper half of the main bearing, which is formed at a region opposed to a downstream side of the circumferential groove formed in the lower half of the main bearing, is partially removed to cause a high-strength bearing base metal to be partially exposed.

Abstract: An image forming apparatus includes a potential applier, a cleaning device and a hardware processor. The cleaning device includes an abutting member abutting a surface of the image carrier and removes residual toner on the surface of the image carrier by means of the abutting member after a toner image formed on the surface of the image carrier is transferred to a transfer material. In a cleaning mode for removing a foreign matter attached to the abutting member of the cleaning device, the hardware processor controls the potential applier to alternately apply a first potential and a second potential which is lower than the first potential to the image carrier so as to periodically change a potential of the abutting member without causing saturation.

Abstract: An image forming apparatus includes a potential applier, a cleaning device and a hardware processor. The cleaning device includes an abutting member abutting a surface of the image carrier and removes residual toner on the surface of the image carrier by means of the abutting member after a toner image formed on the surface of the image carrier is transferred to a transfer material. In a cleaning mode for removing a foreign matter attached to the abutting member of the cleaning device, the hardware processor controls the potential applier to alternately apply a first potential and a second potential which is lower than the first potential to the image carrier so as to periodically change a potential of the abutting member without causing saturation.

Abstract: A hydro dynamic bearing device comprising an upper half of a main bearing and a lower half of the main bearing, wherein the upper half of the main bearing is lined with a low-strength metal such as a Babbitt metal, wherein a circumferential groove is formed in the lower half of the main bearing, and wherein the low-strength metal of the upper half of the main bearing, which is formed at a region opposed to a downstream side of the circumferential groove formed in the lower half of the main bearing, is partially removed to cause a high-strength bearing base metal to be partially exposed.

Abstract: A hydro dynamic bearing device comprising an upper half of a main bearing and a lower half of the main bearing, wherein the upper half of the main bearing is lined with a low-strength metal such as a Babbitt metal, wherein a circumferential groove is formed in the lower half of the main bearing, and wherein the low-strength metal of the upper half of the main bearing, which is formed at a region opposed to a downstream side of the circumferential groove formed in the lower half of the main bearing, is partially removed to cause a high-strength bearing base metal to be partially exposed.

Abstract: A hydro dynamic bearing device comprising an upper half of a main bearing and a lower half of the main bearing, wherein the upper half of the main bearing is lined with a low-strength metal such as a Babbitt metal, wherein a circumferential groove is formed in the lower half of the main bearing, and wherein the low-strength metal of the upper half of the main bearing, which is formed at a region opposed to a downstream side of the circumferential groove formed in the lower half of the main bearing, is partially removed to cause a high-strength bearing base metal to be partially exposed.

Abstract: An image forming apparatus includes a density sensor that measures density of patch images formed on an image carrier; and a controller that forms patch images having respectively plural density types in which image forming conditions are different respectively and corrects the image forming conditions based on measured density values of the patch images by the density sensor. The controller causes a first irradiation light amount by the light emitting section when measuring patch images whose ratio covered by toner of the image carrier is a prescribed value or more to be set different from a second irradiation light amount by the light emitting section when measuring patch images whose ratio covered by toner of the image carrier is less than the prescribed value.