Method for the formation of outline images corresponding to the peripheral outlines of document's images

A method for forming by photocopying an outline of an image, said method comprising:

• a first step of charging an electrostatic latent image bearing member to a predetermined surface potential and charge polarity;
• a second step of irradiating the charged electrostatic latent image bearing member to thereby form a positive electrostatic image thereon having an image portion with a surface potential corresponding to said predetermined surface potential and a non-image portion having a substantially lower surface potential;
• a third step of recharging the thus irrdiated electrostatic latent image bearing member with a scorotron charger having a grid by applying a voltage to the grid with the same polarity as the polarity of the predetermined surface potential of said first step and a value slightly lower than the surface potential of the image portion and substantially higher than the surface potential of the non-image portion of the electrostatic latent image formed by said second step for raising the potential of the non-image portion other than around the outside edge of the image portion to a potential approximately equal to the voltage of said grid;
• and
• a fourth step of developing the electrostatic latent image formed in said third step with a reversal development by using a toner charged to a polarity the same as the first step of charging and a voltage lower than the potential to which the non-image portion has been raised by the grid voltage of said third step.

A method for forming by photocopying an outline around the outside of an image, said method comprising:

• a first step of charging an electrostatic latent image bearing member to a predetermined surface potential and charge polarity;
• a second step of irradiating the charged electrostatic latent image bearing member to thereby form a positive electrostatic image thereon having am image portion with a surface potential corresponding to said predetermined surface potential and a non-image portion having a substantially lower surface potential;
• a third step of recharging the thus irradiated electrostatic latent image bearing member with a scorotron charger having a grid by applying a voltage to the grid with the same polarity as the polarity of the predetermined surface potential of said first step and a value slightly lower than the surface potential of the image portion and substantially higher than the surface potential of the non-image portion of the electrostatic latent image formed by said second step for raising the potential of the non-image portion other than around the outside of the edge of the image portion to a potential approximately equal to the voltage of said grid;
• and
• a fourth step of developing the electrostatic latent image formed in said third step with a reversal development by using a non-magnetic toner charged to a polarity the same as the first step of charging and a voltage slightly lower than the potential to which the non-image portion has been raised by the grid voltage of said third step.

A method for forming by photocopying an outline of an image, said method comprising:

• a first step of charging an electrostatic latent image bearing member to a predetermined surface potential and charge polarity;
• a second step of irradiating the charged electrostatic latent image bearing member to thereby form a positive electrostatic image thereon having an image portion with a surface potential corresponding to said predetermined surface potential and a non-image portion having a substantially lower surface potential;
• a third step of recharging the thus irradiated electrostatic latent image bearing member with a scorotron charger for raising the potential of the non-image portion other than an outline portion around the edge of the image portion for giving the outline portion a potential lower than the potential of the remainder of the image portion;
• and
• a fourth step of developing the electrostatic latent image formed in said third step with a reversal development by using a toner charged to a polarity the same as the first step of charging and a voltage lower than the potential of the remainder of the image portion.