Semiconductor Laser Driving Circuit for Encoder-Free Position Detection
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Solution Overview
Problem
Conventional object detection apparatuses face challenges in accurately detecting the scanning position while maintaining cost-effectiveness, often requiring rotary encoders that increase parts count, size, and cost.
Innovation Solution
The use of a semiconductor laser driving circuit with two switching circuits and pulse generation circuits to drive a semiconductor laser, allowing accurate scanning position detection without a rotary encoder, thereby reducing costs and parts count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a rotary encoder is used to accurately detect the scanning position, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the scanning position detection function from the rotary encoder and implements it through a software-based approach using a counter that increments based on the number of light pulses emitted. This removes the need for the rotary encoder hardware while maintaining detection accuracy.
Solution Approach 2:
The patent replaces the mechanical rotary encoder system with an electronic/software-based counting system. The counter records the number of light pulses emitted, and the scanning position is calculated based on this count, substituting mechanical detection with electronic computation.
2Measurement precision
If a rotary encoder is used to accurately detect the scanning position, then measurement precision is improved, but cost increases
Solution Approach 1:
The patent extracts the scanning position detection function from the rotary encoder and implements it through a software-based approach using a counter that increments based on the number of light pulses emitted. This removes the need for the rotary encoder hardware while maintaining detection accuracy.
Solution Approach 2:
The patent uses a simple counter and pulse generation circuit instead of an expensive rotary encoder. The scanning position is determined by counting light pulses, which is a low-cost electronic approach compared to the mechanical rotary encoder system.
3Measurement precision
If a rotary encoder is used to accurately detect the scanning position, then measurement precision is improved, but apparatus size increases
Solution Approach 1:
The patent extracts the scanning position detection function from the rotary encoder and implements it through a software-based approach using a counter that increments based on the number of light pulses emitted. This removes the need for the rotary encoder hardware while maintaining detection accuracy.
Solution Approach 2:
The patent replaces the mechanical rotary encoder system with an electronic/software-based counting system. The counter records the number of light pulses emitted, and the scanning position is calculated based on this count, substituting mechanical detection with electronic computation.
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 approach enables accurate detection of scanning positions and object information while suppressing increases in cost and apparatus size, improving reliability and detection accuracy.
Implementation Method 1
a light emitting unit which emits light in the first time slot and in the second time slot
Implementation Method 2
a light receiving unit which receives light reflected by an object and generates a detection signal
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A semiconductor laser driving apparatus (100) for driving a semiconductor laser (LD) serving as a light source for optical scanning, the semiconductor laser driving apparatus (100) includes: first and second switching elements (Q1, Q2) that are each capable of switching energization of the semiconductor laser (LD) ON/OFF; a first pulse generation unit (1) that intermittently outputs first driving pulses to the first switching element (Q1) in a first time slot; and a second pulse generation unit (2) that outputs a second driving pulse to the second switching element (Q2) in a second time slot different from the first time slot.