Method of developing electrostatic images
AssigneeEastman Kodak Company
InventorsDinesh Tyagi, Dennis E. Demeyer, James H. Anderson
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Abstract
A method of developing electrostatic images with a two component developer avoids the break-in period of developer by providing a fresh mixture of carrier and toner, which toner has a first particle size but replenishes the mixture in use with toner having a second particle size larger than the first particle size. This compensates for the tendency of electrostatic images to preferentially attract the larger particles in a toner mixture.
Claims16
In a method of developing electrostatic images which includes:
- providing a fresh mixture of magnetic carrier and toner which toner has a first particle size distribution having a volume weighted mean and the carrier having a coercivity of at least 300 gauss and being coated with an insulative coating,
- applying toner to the electrostatic images from the mixture as the carrier flips and moves throughh a development zone, the step of applying the toner having a tendency to prefer the application of larger particles of toner over smaller particles from the mixture to the images, thereby reducing the mean particle size of the toner in the mixture, and
- replenishing the toner used in the method by supplying replenishment toner to the mixture,
- the improvement comprising replenishing the toner by adding toner having a particle size distribution comparable to that of the toner removed in the toner applying step and having a volume weighted mean larger than the volume weighted mean of the first particle size distribution, to stabilize the particle size distribution of the toner in the mixture at the first particle size distribution.
A method of developing electrostatic images comprising:
- providing a fresh mixture of carrier and toner which toner has a first particle size distribution having a first volume weighted mean,
- applying toner to the electrostatic images from the mixture, and
- replenishing the toner used in the method with toner having a second volume weighted mean between 0.3 and 1.2 microns larger than the first volume weighted mean.
In a method of depositing a toner onto a member which includes:
- providing a mixture of magnetic carrier and toner which toner has a first particle size distribution having a volume weighted mean and the carrier having a coercivity of at least 300 gauss and being coated with an insulative coating,
- applying toner to the member from the mixture as the carrier flips and moves through a development zone, the step of applying the toner having a tendency to prefer the application of larger particles of toner over smaller particles from the mixture to the member, thereby reducing the mean particle size of the toner in the mixture, and
- replenishing the toner used in the method by supplying replenishment toner to the mixture,
- the improvement comprising replenishing the toner by adding toner having a particle size distribution comparable to that of the toner removed in the toner applying step and having a volume weighted mean larger than the volume weighted mean of the first particle size distribution, to stabilize the particle size distribution of the toner in the mixture at the first particle size distribution.
Dependencies are inferred from the claim text.