Image forming apparatus having an optical sensor for converting a toner adhesion amount and image forming method

摘要

An image forming apparatus includes an image bearer to bear a black toner pattern formed with a black toner image under an increased exposure amount and an increased developing bias. A first optical sensor detects an amount of reflection light reflected by the black toner pattern on the image bearer. The first optical sensor includes a light-emitting element to emit light toward the black toner pattern on the image bearer and a light-receiving element to receive the reflection light reflected by the black toner pattern on the image bearer. A toner adhesion amount converter converts the amount of the reflection light detected by the first optical sensor into a toner adhesion amount of toner adhered to the image bearer and adjusts an image density according to the toner adhesion amount.

主权项

1. An image forming apparatus, comprising:
an exposure device configured to form an electrostatic latent image under an increased exposure amount; a developing device configured to visualize the electrostatic latent image as a black toner image under an increased developing bias; a rotatable image bearer configured to bear a black toner pattern formed with the black toner image; an optical sensor, opposite the image bearer, configured to detect an amount of reflection light reflected by the black toner pattern on the image bearer, the optical sensor including:
a light-emitting element configured to emit light toward the black toner pattern on the image bearer; anda light-receiving element configured to receive the reflection light reflected by the black toner pattern on the image bearer; anda toner adhesion amount converter, operatively connected to the exposure device, the developing device, and the optical sensor, configured to convert the amount of the reflection light detected by the optical sensor into a toner adhesion amount of toner adhered to the image bearer and adjust an image density according to the toner adhesion amount, wherein the toner adhesion amount is calibrated based on at least one of a result of the optical sensor with a white reference plate provided inside the optical sensor and a plurality of toner patterns having different image densities, respectively, with the optical sensor that detects a specular reflection light and a diffuse reflection light.