Hybrid Electrophotographic Lithography for Variable Data Printing
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Solution Overview
Problem
Current lithographic and offset printing systems are not suitable for high-speed variable data printing due to high viscosity of offset inks, high surface adhesion forces, and the high cost and limitations of special inks and toners, which restrict their use in nozzle-based inkjet and electrophotographic systems.
Innovation Solution
A hybrid electrophotographic and lithographic system that uses an electrophotographic subsystem with a photoreceptor, charging, exposure, and development processes to create a latent image with image definition material, which is then transferred to a reimageable surface and inked, allowing for variable content printing without complex toners and systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If offset inks are used in traditional lithographic printing, then high-quality printing with high color pigment content is achieved, but the high viscosity and high surface adhesion forces make them unsuitable for nozzle-based inkjet and electrophotographic systems
Solution Approach 1:
The patent introduces an intermediary process where offset ink is first transferred to a photoreceptor drum in a latent image form, then developed with toner particles that are suitable for electrophotographic transfer. This intermediary step allows the ink to be converted into a form compatible with electrophotographic systems while maintaining the quality benefits of offset ink
Solution Approach 2:
The patent changes the physical state and properties of the marking material by converting liquid offset ink into solid toner particles through the electrophotographic process. This parameter change from liquid to solid state, and from high viscosity to free-flowing particles, enables compatibility with electrophotographic systems while preserving the original ink's color and quality characteristics
2Manufacturing precision
If permanently patterned printing plates are used, then high-quality printing is achieved, but the cost per copy increases for shorter print runs and variable data printing is not possible
Solution Approach 1:
The patent replaces static, permanently patterned plates with a dynamic system where the imaging plate is recharged and re-imaged for each print run. This allows the same physical plate to be reused indefinitely with different images, eliminating the need for new plates for each job and enabling both short runs and variable data printing while maintaining lithographic quality
3Stability of the object's composition
If permanently patterned printing plates are used, then consistent printing is achieved, but the ability to print variable data from one page to the next is lost
Solution Approach 1:
The patent creates a dynamic imaging system where the photoreceptor plate can be recharged, re-exposed, and re-developed for each print job. This allows the same physical plate to consistently produce high-quality prints while adapting to different images and data requirements, combining printing consistency with variable data capability
Solution Approach 2:
The patent uses the photoreceptor plate as a reusable master that can be repeatedly copied onto different substrates. The plate itself remains unchanged and can be re-imaged, allowing consistent reproduction of high-quality images while enabling variable data through re-imaging with different content
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables high-speed variable data printing with low-cost, high-quality ink images by using image definition materials that are ink-philic and reimageable surfaces that reject ink, reducing costs and improving print quality for shorter print runs.
Implementation Method 1
A light beam from the exposure subsystem is then scanned and pulsed onto the surface of the charged photoreceptor to thereby write a charge pattern representing a latent positive image onto the photoreceptor surface
Implementation Method 2
The latent charge is developed with an image definition material, such as a liquid or dry toner, that is itself charged (or contains charged particles) in such a manner as to be attracted to the latent charge regions on the photoreceptor surface
Data Source
AI summary
A method is disclosed in the context of a system comprises an electrophotographic subsystem, a transfer subsystem, an imaging member, and an inking subsystem. The electrophotographic subsystem comprises a photoreceptor, a charging subsystem, an exposure subsystem, and a development subsystem. In operation, the photoreceptor is charged areawise. An exposure pattern is formed by the exposure subsystem on the surface of the charged photoreceptor to thereby write a latent charge image onto the photoreceptor surface. The image is developed with an image definition material, such as a dampening fluid. The image definition material forms a positive pattern of the image to be printed. The image pattern is then transferred to the reimageable surface. The transferred pattern is then developed by selectively applying an ink over regions of image definition material. The inked image may be transferred to a substrate.