Light Scanning Board Layout to Reduce Sensor Stray Light
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light scanning apparatuses for image forming devices suffer from stray light interference due to the mounting configuration of light-emitting modules and optical sensors on the same board surface, leading to erroneous detection by the optical sensor.
Innovation Solution
The light scanning apparatus is designed with a board configuration where the light-emitting modules are mounted on one surface and the optical sensor is mounted on the opposite surface, with a through-hole allowing scanning light to be detected, reducing stray light interference and improving detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the light-emitting module and optical sensor are mounted on the same surface of the board, then the device complexity is reduced and ease of manufacture is improved, but stray light interference occurs causing measurement precision to deteriorate
Solution Approach 1:
The patent applies dimensionality change by mounting the optical sensor on the opposite surface of the board relative to the light-emitting module. Specifically, the light-emitting module is mounted on the front surface while the optical sensor is mounted on the back surface, utilizing the thickness direction of the board to spatially separate components that would otherwise interfere with each other on the same surface.
2Measurement precision
If the optical sensor is mounted on the opposite surface with a through-hole, then stray light interference is reduced improving measurement precision, but device complexity increases
Solution Approach 1:
The patent extracts the optical sensor from the same surface as the light-emitting module and relocates it to the opposite surface of the board. This extraction eliminates the stray light interference problem while the through-hole provides the necessary optical path, balancing precision improvement with acceptable structural complexity.
3Measurement precision
If the optical sensor receives scanning light from the first surface through a through-hole, then stray light reflection is minimized improving measurement precision, but the structure becomes more complex
Solution Approach 1:
The patent utilizes the thickness dimension of the board to create a through-hole that allows scanning light to pass from the front surface to the back surface where the optical sensor is mounted. This dimensional approach minimizes stray light reflection by eliminating the need for the sensor to receive light from the same surface, thereby improving detection accuracy.
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 minimizes stray light reflection, preventing erroneous optical sensor detection and maintaining high precision in latent image formation, while also reducing wire length and radiation from signal lines.
Implementation Method 1
a light-emitting module (laser light source) mounted on a board (circuit board) that emits light
Implementation Method 2
an optical sensor (BD sensor) that detects a deflected light flux and synchronizes a writing timing
Data Source
AI summary
A light scanning apparatus includes a board, a light-emitting module, a driver circuit, a control circuit, and an optical sensor. The board has a first surface and a second surface on both sides in a thickness direction. The light-emitting module is mounted on the board and outputs light to a side of the first surface. The driver circuit is mounted on the board and drives the light-emitting module. The control circuit is mounted on the board and controls the driver circuit. The optical sensor is mounted on the board and receives, from the side of the first surface, scanning light from the light-emitting module as a light source. The board has a connection pad that electrically connects the optical sensor on the second surface.