VCSEL Writing Module Layout for Lower-Heat Digital Printing
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Solution Overview
Problem
High-power VCSELs in digital printing systems generate excessive heat and require high electric current, leading to challenges in heat management and electrical efficiency, particularly due to the high current densities and complex driver circuitry needed to support the light sources.
Innovation Solution
The use of a cascade of at least two VCSEL light-emitting semiconductor junctions connected in series to reduce power consumption and improve heat management, along with integrated electronic modules arranged in two rows with separate electronic driver packages and a flexible circuit board for efficient power delivery and heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-power VCSELs are used to increase printing speed and resolution, then productivity and measurement precision are improved, but heat generation and electric current requirements increase excessively
Solution Approach 1:
The patent divides a single high-power VCSEL into multiple lower-power VCSELs arranged in an array. Each VCSEL operates at reduced power levels, generating less heat individually, while the collective array achieves the required total optical output for high-speed printing. This segmentation resolves the contradiction by maintaining productivity through multiple elements while reducing temperature per element.
2Measurement precision
If high-power VCSELs are used to improve printing resolution and speed, then measurement precision and productivity are enhanced, but the required electric current increases excessively
Solution Approach 1:
The patent employs an array of multiple VCSELs where each element requires only a fraction of the total current that a single high-power VCSEL would need. The current is distributed across parallel or series-parallel configurations of the array elements, reducing the current burden on each individual VCSEL and the overall system while maintaining the optical power needed for high-resolution printing.
3Measurement precision
If complex driver circuitry is used to control high-power VCSELs, then measurement precision and productivity are improved, but device complexity increases
Solution Approach 1:
The patent controls each VCSEL in the array with simplified driver circuitry compared to controlling a single high-power VCSEL. The segmentation allows for independent or grouped control of multiple low-power elements, reducing the complexity of power management, thermal control, and current regulation circuits while achieving the same or better printing precision through the array's collective output.
4Productivity
If high current densities are used to power VCSELs, then productivity is improved, but harmful factors increase due to heat and electrical stress
Solution Approach 1:
The patent distributes the total electrical load across multiple VCSELs in an array, reducing the current density through each individual device. This segmentation lowers electrical stress and heat generation per VCSEL, reducing harmful thermal and electrical effects while maintaining the total optical output required for high-speed printing through the combined output of all array elements.
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
This configuration reduces the electric power required for each light source, enhances heat management, and allows for a more compact and efficient design, minimizing heat generation and improving the reliability of the printing system.
Implementation Method 1
Each light source comprises at least two light-emitting semiconductor junctions electrically connected in series and arranged in one or more vertical-cavity surface-emitting lasers (VCSELs)
Implementation Method 2
selected regions of the coated imaging surface are exposed to laser beams of activated laser elements thereby rendering the particles within the selected regions tacky
Implementation Method 3
the process of transferring an image to ultimately form a printout on the substrate involves a step of radiating a structured light beam on a target surface so as to form the desired image thereon
Data Source
AI summary
A printing system is disclosed which comprises a writing module, and a member having an imaging surface configured to carry a polymer and movable relative to the writing module. The writing module is configured to direct onto the imaging surface a plurality of individually controllable light beams that are spaced from one another in a direction transverse to the direction of movement of the imaging surface, incidence of a light beam on a spot on the imaging surface serving to soften or liquefy the polymer carried by the imaging surface at the spot. The polymer softened or liquefied at the spot can transfer to a substrate or serve as an adhesive on the imaging surface. The writing module comprises a plurality of integrated electronic modules each having an array of individually controllable light sources, each light source producing a respective one of the light beams. In the invention, each light source comprises at least two Vertical-Cavity Surface-Emitting Laser (VCSEL) light-emitting semiconductor junctions connected in series with one another and configured to direct light onto the imaging surface at the same spot as one another.