Exposure Head Dual Light Emitting Board Lens Array
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing exposure heads in electrophotographic systems using organic EL elements suffer from low light output due to light obstruction by TFT circuit wiring, which is inefficient and insufficient for high-speed applications like print on demand.
Innovation Solution
The exposure head design includes two rows of light emitting boards with alternating orientations and separate lens arrays to efficiently condense light onto the photosensitive drum, allowing for multiple exposure and increased light intensity without impairing image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If light is extracted through the glass substrate in existing exposure heads, then the structure is simplified and components are reduced, but light is obstructed by TFT circuit wiring causing low light output
Solution Approach 1:
Instead of extracting light upward through the glass substrate (conventional approach), this patent inverts the light extraction direction to downward through the back surface of the glass substrate. This inversion eliminates obstruction from TFT circuit wiring located on the front surface, thereby resolving the contradiction between structural simplicity and light output intensity
2Productivity
If a single row of light emitting elements is used, then the device is miniaturized and cost is reduced, but light amount to the photosensitive drum is insufficient for high-speed applications
Solution Approach 1:
The patent transitions from a single-row linear arrangement to a two-dimensional array structure with multiple rows of light emitting elements. This dimensional expansion increases the total light output to sufficient levels for high-speed applications while maintaining the miniaturized and cost-effective advantages of the LED array approach
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 enhances light utilization and output, ensuring sufficient light reaches the photosensitive drum for high-speed applications without compromising image quality.
Implementation Method 1
a rod lens array condensing the light of the row of the light emitting elements onto the photosensitive drum
Data Source
AI summary
An exposure head includes a light emitting board group, a first lens array, and a second lens array. The light emitting board group disposes a plurality of light emitting boards each including a plurality of light emitting elements disposed side by side in a second direction intersecting with the first direction. The plurality of light emitting boards are disposed along the second direction and alternately in the first direction. The light emitting board group includes a first light emitting board group and a second light emitting board group. The first lens array condenses light emitted from the plurality of light emitting elements disposed on the first light emitting board group onto the surface of the image bearing member. The second lens array condenses light emitted from the plurality of light emitting elements disposed on the second light emitting board group onto the surface of the image bearing member.