Patent ID: 9164460
Filing Date: 2015-10-20
Classification: G03G

Abstract:
1. An image forming apparatus, comprising: a photoreceptor body; a charging device that charges the photoreceptor body; an exposure device that exposes the photoreceptor body to form an electrostatic latent image; a development device that develops the electrostatic latent image as a toner image using a toner; a density detection sensor configured to detect density of an image, the density detection sensor having a light emitting element for emitting light and a light receiving element for receiving a reflection reflected from the image when the light emitting element emits light to the image; and a controller configured to selectively execute a correction mode in a warm-up period from power-on of a main body of the image forming apparatus until allowing an image to be formed on a recording medium, the controller corrects a gamma look-up table based on detection results of a plurality of image patches having different densities from each other detected by the density detection sensor in the correction mode; wherein the controller forms a first image in the warm-up period and then forms a second image in a case when a first detection result obtained by detecting the first image with the density detection sensor is out of a first predetermined range, wherein the controller allows an image to be formed on a recording medium without executing the correction mode in a case when the first detection result is within the first predetermined range or a second detection result obtained by detecting the second image with the density detection sensor is within a second predetermined range, the controller executes the correction mode in a case when the first detection result and the second detection result are out of the first predetermined range and the second predetermined range, respectively; wherein the first image is a toner image obtained by a potential difference between a DC developing bias applied to the developing device and a potential of a surface of the photoreceptor body being exposed by the exposure device after being charged by the charging device, and the second image is a toner image obtained by a potential difference between a DC developing bias applied to the developing device and a potential of the surface of the photoreceptor body, without being substantially exposed by the exposure device after being charged by the charging device.