Deposited toner quantity measuring method and image forming apparatus using the same
AssigneeRicoh Company, Ltd.
InventorsKoji Hayashi, Takashi Bisaiji
Life of this patent
Estimating the term…
Abstract
The deposited toner quantity measuring method and image forming apparatus using the same according to the present invention estimates the development characteristics from a quantity of deposited toner obtained by the optional sensor and from a result of detection by the electric potential sensor, and corrects an image signal from the estimated development characteristics.
Claims14
A deposited toner quantity measuring method for measuring a quantity of deposited toner corresponding to a gradient of a gradated density pattern by irradiating a beam onto a visual image of a gradated density pattern formed on an image carrier and detecting a quantity of reflected light with an electrophotosensitive chip, comprising the steps of:
- detecting a surface electric potential on an electrostatic latent image of the gradated density pattern;
- measuring a quantity of reflected light from a visual image of the gradated density pattern;
- classifying the quantity of reflected light as corresponding to a saturated range or an unsaturated range;
- obtaining a first relational expression between a surface electric potential and a quantity of deposited toner when the quantity of reflected light is in said unsaturated range;
- obtaining a second relational expression between the quantity of reflected light in said unsaturated range and the quantity of deposited toner;
- and
- computing a quantity of deposited toner using said second relational expression when the quantity of reflected light is in said unsaturated range, and using said first relational expression when the quantity of reflected light is in said saturated region.
An image forming apparatus having a gradated density pattern forming means for forming an electrostatic image of a gradated density pattern on an image carrier, a surface electric potential detecting means for detecting a surface electric potential of the electrostatic image of said gradated density pattern, a developing means for forming a visual image of the gradated density pattern on the image carrier by developing the electrostatic latent image of said gradated density pattern, an electrophotosensitive means for detecting a quantity of reflected light from a visual image of a gradated density pattern formed on said image carrier, and an image forming means for forming an electrostatic image on an image carrier depending on an image signal, comprising:
- a classifying means for classifying the quantity of reflected light as being in a saturated range or an unsaturated range;
- a first storage means for storing a result of detection by said surface electric potential detecting means;
- a second storage means for storing a result of detection by said electrophotosensitive means when said classifying means has classified the quantity of reflected light as being in said saturated range and for storing a quantity of deposited toner obtained from a result of detection by said electrophotosensitive means when said classifying means has classified the quantity of reflected light as being in said unsaturated range;
- and
- means for computing a deposited toner quantity based on the result of detection stored in said second storage means when the quantity of reflected light is in said unsaturated range, and when the quantity of reflected light is in said saturated range, based on the result of detection stored in said first storage means and a quantity of deposited toner in said unsaturated range.
An image forming apparatus having a gradated density pattern forming means for forming an electrostatic image of a gradated density pattern on an image carrier, a surface electric potential detecting means for detecting a surface electric potential of the electrostatic image of said gradated density pattern, a developing means for forming a visual image of the gradated density pattern on the image carrier by developing the electrostatic latent image of said gradated density pattern, an electrophotosensitive means for detecting a quantity of reflected light from a visual image of a gradated density pattern formed on said image carrier, and an image forming means for forming an electrostatic image on an image carrier depending on an image signal, comprising:
- a classifying means for classifying the quantity of reflected light as being in a saturated range or an unsaturated range;
- a first storage means for storing a result of detection by said surface electric potential detecting means;
- a second storage means for storing a result of detection by said electrophotosensitive means when said classifying means has classified the quantity of reflected light as being in said saturated range and for storing a quantity of deposited toner obtained from a result of detection by said electrophotosensitive means when said classifying means has classified the quantity of reflected light as being in said unsaturated range;
- means for computing a deposited toner quantity based on the result of detection stored in said second storage means when the quantity of reflected light is in said unsaturated range, and when the quantity of reflected light is in said saturated range based on the result of detection stored in said first storage means and a quantity of deposited toner in said unsaturated range;
- and
- an image signal correcting means for correcting an image signal by altering development characteristics according to a quantity of deposited toner computed by said computing means and said result of detection by said surface electric potential detecting means.
Dependencies are inferred from the claim text.