摘要 |
A remaining amount of toner in an image forming apparatus is determined. The amount of toner remaining determines whether the image forminng apparatus may be in a low toner state or a no toner state. An estimate of the amount of toner remaining is obtained by accurately estimating the amount of toner consumed. Latent patch images formed on a photoconductive member 1 by an exposure unit 3 are developed by developing means 5 to obtain patch images. Densities of the patch images are measured by a patch sensor 22, and the contents of a weighting coefficient LUT 44 are changed. Meanwhile, the amount of toner developed, which corresponds to the changed weighting coefficient, is calculated by a development toner weight calculating unit 45 for each pixel on the basis of an exposure signal. This amount of toner developed is summed by a development toner weight summing means 46. <IMAGE> |