A new set of proposed standards has been developed for integration of fascimile transmission and the Internet, and products based on these standards are now available. An Internet fax unit sends a TIFF file as an e-mail attachment to another Internet fax or a PC with an e-mail address. On receipt of such an E-mail, an Internet fax prints out the image data as a legacy fax machine does. The image data received by a PC can be displayed with a TIFF viewer, realizing paper-less fax communications.A second-generation Internet fax will add color image transmission/reception capability and accept photo images directly from digital cameras. It has a new mode of operation in which it does not send a TIFF file as an e-mail attachment. Instead, the scanned image is sent to and stored in a predetermined WWW server, and the Internet fax unit just sends an e-mail to notify the recipient of the URL of the image.

Correct toner charging, its sign, magnitude, and distribution, are critical parameters in any electrophotographic development system. This review summarizes recent advances in our understanding of the physics and chemistry governing the toner charging process. These advances include (1) the experimental demonstration that toner charging data are consistent with the theory that toner particles charge up until a material dependent electric field is created at the surface of the toner particle, (2) the suggestion and verification that the surface “work function” of a toner can be expressed as a time dependent surface area weighed sum of the “work functions” of the toner constituents, (3) the experimental and theoretical studies showing that toner charging is not determined by air breakdown, and (4) experimental measurements showing that the toner charge distribution is intrinsically wide, as though a statistical process underlies the charging process, with wrong sign toner resulting from the tail of the distribution.

With the development of inkjet technology, high-speed printing was enabled with wider printhead and/or higher carriage scan speed. Photo quality images were achieved with smaller drops and multi-level, high-resolution printing. Due to the inherent features of thermal inkjet, the aerodynamic effect will be more significant in the future inkjet development.This paper presents the numerical simulation of the aerodynamic effect on inkjet main drop and satellite dot placement. In this model, the stationary flow and plane Couette flow were used to simplify the flow patterns underneath the printhead. Non-spherical drop shape and evaporation were neglected. Droplets were traced with the Lagrangian approach. The aerodynamic effect on main drop and satellite motion and dot placement were simulated in three simplified cases and correlated with print samples. This model can also be used to simulate the aerodynamic effect on future inkjet printing with small drops and/or with high scan speed.

The average toner charge-to-mass ratio (q/m) is an important metric for two-component xerographic developers since xerographic development of solid and line or dot images is normally a simple inverse function of q/m. However, q/m is a distributed function, and for other nonimage processes such as background development and machine dirt generation, the “tails” of the charge distribution are more important than the average q/m value. Thus, a detailed assessment of any particular xerographic developer should involve the measurement and analysis of the entire charge spectrum. This viewpoint will be illustrated in the present paper by a comparison of simultaneous average q/m data (from a total-blow-off procedure) and distributed charge/size (q/d) data (from a charge spectrum). In particular, the direct connection between these two types of charge measurements will be highlighted, both for normal charging processes and for admix processes that involve the addition of uncharged toner to a charged developer. Additionally, both positive and negative charging processes will be considered, with a common set of test toners being driven to both polarities via specific carrier coatings.

A recent paper, presented at NIP12 in San Antonio, described the relationship between heater power density and bubble nucleation. While the experimental results validated the model, it left an unanswered question, that is; what is the effect of power density and bubble nucleation on jetting performance? Increasing firing frequencies combined with more dense heater arrays act together to decrease the time available for pulsing individual heaters. This pushes power density upwards. However, thin film reliability issues often work in the opposite direction. Lower power density pulses, in general, permit longer heater lifetimes. Independent of these issues, there are jetting performance considerations. While heater lifetime effects are important, only the jetting performance issues are examined in this paper. In particular, this paper deals with droplet velocity and stability and their relationship to heater power density. Experimental data is presented along with simulation results. Bubble momentum is computed and used to explain the nonlinear velocity response to heater power density. Also, the spread of nucleation probability across the heater surface, is used to compute nucleation quality. The nucleation quality term has a direct relationship to the power density regime responsible for bubble instability induced droplet velocity variation.

To understand tribocharging characteristic of polymers containing CCA, influence of the amount of surface CCA on the toner charging was investigated for various CCA's. The charging behavior of the toners with CCA was strongly related to the crystal form and solubility into resin of CCA particles. The amount of surface CCA influenced the tribochaging rate of toners. TSC measurements indicate that the interface between CCA and resin works as charging sites for tribocharging of toners.

We have reported earlier (IS&T's NIP13) the stabilisation of the ink jet in the flight by means of polymeric additives. On the other hand it was shown theoretically that polymeric additives can influence on vapor bubble dynamics, in particularly they can reduce the bubble growth and (or) collapse. In dependence on different factors this reduction may lead to some jet velocity losses but in the same time it may lead to suppression of cavitation damage of the heater surface. To experimental observation of discussed phenomena the visualisation of vapor bubble growth and collapse in different polymeric fluids was carried out. The polyacrylamide solutions of molecular mass of 500,000 -11,000,000 and concentrations of 0 - 6 % were studied. It was found that only high concentrations of polymer solution causes the considerable reduction of bubble growth and collapse in comparison with pure solvent. These concentrations far exceed the concentrations which provide the most appropriate stabilisation effect on jet flight. In all other investigated cases the bubble dynamics is well described by Rayleigh theory and does not differ significantly from one of pure solvent. Therefore there is the range of polymer parameters which provides the jet stabilisation without the variance in vapor bubble dynamics.

Many toners use resins which are crosslinked to some degree. These resins are used in toners due to the fusing latitude they impart to the toner. These partially crosslinked or “gel” type resins are relaxed in the melt mixing step used to prepare the toner, thus their properties are different from the “as manufactured material”. We have studied the relaxation of the polymeric structure in a gel resin using a Haake batch mixer to simulate the melt mixing step. Resin samples were compared using a Shimadzu CFT-500C flow tester and a Rheometrics RMS Rheometer. Our data show that the properties of the resulting polymer are a function of the shear experienced by the polymer during the melt mixing step. The temperature at which the melt mixing step is performed appears to be the dominant variable influencing the shearing of the polymer.

In the small color printer market, long life of print heads is a key factor to realize running cost reduction and a non-disposable engine for environment-friendly use. In the Thermal Ink Jet (TIJ) printers, kogation of ink components onto the heater due to thermal cycle caused shorter life of the heads.To solve this problem, we studied a removal method of kogation by a drive pulse called a “Recovery Pulse” which is different from that for printing. As the result, we have found that kogation can be removed efficiently from the heater by adding the recovery pulses with smaller drive energy than that for normal printing. That is, apparently this recovery is made not by a cavitation induced self-healing, but by the mechanism of residue floating or detachment. Based on the study, it can be concluded that the recovery pulse using the mechanism is effective for removal of kogation.Subsequently, we have developed a system to utilize the recovery pulses in the maintenance operations effectively and vary the drive method of print heads depending on the print history (aging). As the result, we have realized a non-disposable TIJ print head using water fast inks.

The magnetic force acting on magnetic toner from the magnetic latent image recorded by longitudinal recording is theoretically analyzed. Heretofore analysis using sinusoidal approximation of magnetization has been reported wherein the force acting on toner can be several hundred times the force of gravity and it is not much smaller than the force used in electrostatic printing. This paper employs arctangent approximation of magnetization for digital longitudinal recording. A new approximate equation of the force attracting toner is presented which is applied to the magnetic printer using metal thin film recording medium and dry toner. Typically, the recording medium comprises Co-Ni-P plated metal thin film with the thickness of 1 micrometer. The toner comprises soft magnetic toner with the diameter of 10 micrometers. The resulting force acting on toner can be about three orders larger than the force of gravity. It is almost the same as the force used in electrophotography.