Technology for High-Reliability, High-Durability Photoreceptors
Ricoh has developed a technology for high-reliability, high-durability photoreceptors that make possible reduced service costs for high-speed copiers for the commercial printing market and the corporate in-house printing market.
Photoreceptor Quality for Demanding Commercial Use
In the commercial printing market and corporate in-house printing market, in recent years a shift to high-variety, small-lot printing has resulted in increased needs for color print on demand (POD), the capability to print at low cost the exact quantity of printed materials required as and when they are required. Thanks to a newly developed high-speed print engine that incorporates a photoreceptor developed using this technology, the RICOH Pro C900 realizes higher definition, higher reliability and durability, and higher productivity as well as sharp reductions in size and weight in comparison with previous machines. This photoreceptor plays an especially important role in the assurance of high reliability and durability.
The Structure of the Newly Developed Functionally Separated Photoreceptor
As shown in Figure 1, the newly developed high-reliability, high-durability photoreceptor has a structure consisting of functionally separated layers on top of a large-diameter (100mm) aluminum support. These layers are configured as described below in a high-sensitivity photoreceptor suitable for high-speed machines.
(a) Charge generation layer (CGL)
(b) Charge transport layer (CTL)
(c) Intermediate layer (IL) ? Improves electrostatic stability by
increasing voltage endurance and preventing local leaks
(d) Overcoat layer (OL) ? Combines the required electrical characteristics and abrasion resistance by means of the adoption of a new material developed in-house on the basis of materials technologies nurtured over many years.
Through a combination of these functionally separated layers, the newly developed photoreceptor realizes the high-reliability and high-durability required for commercial use by achieving balance between mechanical abrasion resistance and electrical stability.
Figure 1: The structure of the newly developed photoreceptor
An Independently Developed Material Combining Electrical Characteristic Stability and Durability
The application of an overcoat to increase reliability is a commonplace technique in widespread use. However, the simple application of an overcoat to copier photoreceptors would obstruct electrical charge movement, an electrical characteristic that is a basic characteristic of photoreceptors, which would result in problems such as image density deterioration. Consequently, Ricoh developed in-house a new material that offers an increase in durability with no loss of electrical characteristics. By using this material in an overcoat, Ricoh has realized highly reliable photoreceptors that combine greater durability with electrical characteristic stability.
This has made it possible to ensure stable copier operation and greatly reduce downtime and service costs required to respond to mechanical failure.
