Xerographic process development

From a commercial standpoint, except in the case of matnre technology associated with the xerographic process, the present state of development of amorphous... 

A transfer material has been developed for transferring monochrome and full-color images produced by a xerographic process or a dry toner printing onto a substrate. The process requires the use of a film from TPX as the transfer material. This material is used to transfer the xerographic or dry toner image onto the substrate with the application of heat and pressure (27). 

Measurements such as illustrated in Fig. 16 are also widely used for system evaluation. By dividing the overall xerographic process into exposure, photoreceptor, and development subsystems, then describing each subsystem with an appropriate transfer function, the output image density can be related to the input density through a four-quadrant plot (Paxton, 1978 Pai and Melnyk, 1986). In such a manner, the effects of changes in the various subsystems on the output image density can be readily determined. 

Early developments in xerography have been reviewed by Carlson (1965) and Schaffert (1965, 1975). More recent work has been reviewed by Scharfe (1984), Williams (1984), Mort (1989), and Schein (1988, 1992, 1995). These reviews are largely concerned with various steps in the xerographic process and... 

Figure 8 shows the xerographic process from the viewpoint of the toner. The material is fed into the development chamber, charged (usually by triboelectri-fication), and applied to the photoconductor surface. Powder which adheres to charged areas of the latent image is then transferred and fused to a sheet of paper or film the residue is cleaned off. Let us now consider these steps in greater detail. 

Adhesion and autohesion are critical factors in the following stages of the xerographic process (Fig. XII.5) the attachment of the toner particles 3 on the surface of a carrier particle 4 and formation of the developer complex the development, i.e., detachment of the toner particles and retention of these particles on the charged sections of the semiconductor layer 1 the detachment of particles from the semiconductor layer and transfer of the resultant image to paper 5 and the fixing of the image 7. 

The discovery of photoconductivity dates back to 1873 when W. Smith found the effect in selenium. Based on this discovery C. F. Carlson developed the principles of the xerographic process already in 1938. 

The discovery of photoconductivity dates back to 1873 when W. Smith found the effect in selenium. Based on this discovery C.F. Carlson developed the principles of the xerographic process in 1938. Photoconductivity in polymers was first discovered in 1957 by Hoegl [1,2]. He found that poly(A-vinylcarbazole) (PVK) sensitized with suitable electron acceptors showed high enough levels of photoconductivity to be useful in practical application like electrophotography. As a result of the following activities IBM... 

Greek for dry (xeros) and writing (graphos). The process was invented in 1938 and patented in 1940 by Chester F. Carlson and involves several different physical phenomena. At the time the invention was first made these processes were poorly understood and the first demonstration copies were not of the quality we are used to today. Carlson demonstrated his invention to twenty American companies and generated an enthusiastic lack of interest . Nevertheless, development was undertaken initially by the Battelle Memorial Institute and subsequently by the Haloid Company, now known as the Xerox Corporation. The first commercial xerographic copier appeared on the market in 1959 and is today a worldwide multi-billion pound industry. 

Xerographic discharge, which is a highly space-charge-perturbed process, is therefore characterized by significant dispersion in the arrival times of photoinjected carriers. In some cases, the transit times of the slowest carriers are 10 times or more than the transit times of the fast carriers. However, the slowest carriers, too, must exit the TL before the photoreceptor reaches the development zone, typically 0.3-1.0 s after exposure. In practice, carrier mobilities that significantly exceed 10 cm /V-s are desirable. 

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