Image forming apparatus and image processing apparatus
AssigneeCanon Kabushiki Kaisha
InventorTomohisa Itagaki
Life of this patent
Estimating the term…
Abstract
An image forming apparatus forms an image for a latent image portion of which density is relatively higher with a dark color image forming portion, and forms an image for a background portion of which density is relatively decreased or of which image disappears, with a light color image forming portion, with respect to portions of forgery-preventing pattern image in which the density contrasts for the portions mutually differ after copying.
Claims10
An image forming apparatus comprising:
- a dark color image forming station for forming an image with such a toner of at least one set of recording materials having the same hue and different lightness as has a lower lightness;
- a light color image forming station for forming an image with such a toner of the at least one set of recording materials having the same hue and different lightness as has a higher lightness;
- and
- a control portion for effecting control so that an image to be emphasized, including a first image portion and a second image portion, by partly disappearing or by relatively and partly decreasing in density is formable,
- wherein the first image portion has a relatively low line number of an image to be formed and is formable substantially only with the toner having the lower lightness, and the second image portion has a relatively high line number of an image to be formed and is formable substantially only with the toner having the higher lightness.
An image forming apparatus comprising:
- a dark color image forming station for forming an image with such a toner of at least one set of recording materials having the same hue and different lightness as has a lower lightness;
- a light color image forming station for forming an image with such a toner of the at least one set of recording materials having the same hue and different lightness as has a higher lightness;
- and
- a control portion for effecting control so that an image to be emphasized, including a first image portion and a second image portion, by partly disappearing or by relatively and partly decreasing in density is formable,
- wherein the first image portion is formed by a first dither and is formable substantially only with the toner having the lower lightness and wherein the second image portion is formed by a second dither having a minimum distance, between isolated dots of an image to be formed, smaller than that of the first dither and is formable substantially only with the toner having the higher lightness.
An image processing apparatus for being used together with an image forming apparatus comprising a dark color image forming station for forming an image with such a toner of recording materials having the same hue and different lightness as has a lower lightness, and a light color image forming station for forming an image with such a toner of the recording materials having the same hue and different lightness as has a higher lightness;
- said image processing apparatus comprising:
- an input portion for inputting thereinto an image data about a forgery-preventing pattern image to be emphasized, including a first image portion and a second image portion, by partly disappearing or by relatively and partly decreasing in density is formable;
- and
- a control portion for effecting control so that the first image portion which has a relatively low line number is formable substantially only with the toner having the lower lightness and that the second image portion which has a relatively high line number is formable substantially only with the toner having the higher lightness.
An image processing apparatus for being used together with an image forming apparatus comprising a dark color image forming station for forming an image with such a toner of recording materials having the same hue and different lightness as has a lower lightness, and a light color image forming station for forming an image with such a toner of the recording materials having the same hue and different lightness as has a higher lightness;
- said image processing apparatus comprising:
- an input portion for inputting thereinto an image data about a forgery-preventing pattern image to be emphasized, including a first image portion and a second image portion, by partly disappearing or by relatively and partly decreasing in density is formable;
- and
- a control portion for effecting control so that the first image portion which is formed by a first dither is formable substantially only with the toner having the lower lightness and that the second image portion which is formed by a second dither with a minimum distance, between isolated dots of an image to be formed, smaller than that of the first dither is formable substantially only with the recording material having the higher lightness.
Dependencies are inferred from the claim text.