LED Print Head Wiring Reduction via Segmented Array Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electrophotographic image forming apparatuses, the existing LED print heads with large numbers of light-emitting diodes (LEDs) face challenges in efficient control and wiring complexity, leading to increased circuit board area and reduced reliability due to the need for numerous wide wirings for current supply.
Innovation Solution
A light-emitting device with plural light-emitting array units, each comprising light-emitting elements, is controlled using a combination of selection and light-up signals, with a signal generating unit sending these signals to reduce wiring complexity by grouping light-emitting elements into pairs and using fewer wide wirings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If each light-emitting element is controlled individually with separate wirings, then control precision is improved, but wiring complexity and circuit board area increase
Solution Approach 1:
The light-emitting elements are divided into multiple light-emitting array units, with each unit containing a specific number of elements (e.g., 2 elements per unit). This segmentation allows individual control of each array unit while reducing the total number of control lines compared to controlling each element separately.
Solution Approach 2:
Multiple light-emitting elements within each array unit share common power supply wirings (anode and cathode connections). By merging the power supply paths for elements within the same array unit, the patent reduces wiring complexity while maintaining the ability to control each array unit independently through selection signals.
2Adaptability or versatility
If individual wirings are provided for each light-emitting element, then control flexibility is improved, but circuit board area increases
Solution Approach 1:
The patent divides the large number of light-emitting elements into multiple array units, enabling selective activation of specific units based on image data requirements. This segmentation maintains control flexibility by allowing independent selection of array units while reducing the overall wiring burden on the circuit board.
Solution Approach 2:
The selection signal lines and power supply lines are designed to serve multiple array units simultaneously. A single selection signal line can control multiple array units by applying selection signals at different timings, and power supply lines serve multiple elements within each array unit, reducing the total number of lines required on the circuit board.
3Power
If numerous wide wirings are used for current supply, then power delivery capability is improved, but reliability decreases
Solution Approach 1:
Multiple light-emitting elements within each array unit share common power supply wirings (anode and cathode connections). By merging the power supply paths, the patent reduces the total number of wirings while maintaining adequate power delivery capability through proper current distribution design in the shared wirings.
Solution Approach 2:
The patent extracts and consolidates the power supply function into shared anode and cathode wirings for each array unit, separating the power delivery function from the control function. This allows the control signals to be transmitted through dedicated selection signal lines while power is supplied through consolidated power supply lines, improving reliability by reducing the total number of connections.
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 number of wirings by approximately two-thirds, minimizing the circuit board area and enhancing reliability by simplifying the control and power supply to the light-emitting elements.
Implementation Method 1
a light-emitting device including: plural light-emitting array units S-A1 to S-A20 and S-B1 to S-B20 which each include plural light-emitting elements
Data Source
AI summary
A light-emitting device includes: plural light-emitting array units that each include plural light-emitting elements, and for which lighting up and not lighting up are controlled by using a combination of a selection signal for selecting a control target for lighting up or not lighting up and a light-up signal for supplying power for lighting up to each light-emitting element forming the plural light-emitting elements; a selection signal generating unit that sends plural selection signals including the selection signal to the plural light-emitting array units; and a light-up signal generating unit that sends plural light-up signals including the light-up signal to the plural light-emitting array units.