Electronic Distance Measuring Instrument Optical Path Folding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electronic distance measuring instruments face challenges in miniaturization due to the large size and weight of their optical systems, primarily because of the restrictions imposed by the size of the lens group and focal length, which hinder weight reduction and compactness.
Innovation Solution
The electronic distance measuring instrument employs a beam splitter and optical path length adjustment components with a hole to allow only the reflected distance measuring light to pass, along with a scanning mirror and image pickup unit, to deflect optical axes and create a coaxial alignment, thereby reducing the length of the light receiving optical system and achieving miniaturization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a large aperture lens group with long focal length is used to achieve high magnification and high resolution sighting, then measurement precision is improved, but the optical system becomes large in size and heavy
Solution Approach 1:
The patent introduces a beam splitter to create a folded optical path, changing the linear arrangement into a two-dimensional configuration. The light receiving optical axis is deflected by the beam splitter to intersect with the projection optical axis, allowing the optical system to achieve the required focal length while reducing the overall instrument size and weight.
Solution Approach 2:
The patent integrates the light receiving optical system within the projection optical system by using the beam splitter to share the optical path. The condenser lens and photodetector are positioned to receive light through the beam splitter, effectively nesting the measurement function within the existing projection structure.
2Measurement precision
If a large aperture lens group with long focal length is used to achieve high magnification and high resolution sighting, then measurement precision is improved, but the optical system becomes large in size
Solution Approach 1:
The patent introduces a beam splitter to create a folded optical path, changing the linear arrangement into a two-dimensional configuration. The light receiving optical axis is deflected by the beam splitter to intersect with the projection optical axis, allowing the optical system to achieve the required focal length while reducing the overall instrument size and weight.
3Measurement precision
If the light receiving optical system is designed with a long focal length to match the lens group, then measurement precision is improved, but the optical axis length increases
Solution Approach 1:
The patent introduces a beam splitter to create a folded optical path, changing the linear arrangement into a two-dimensional configuration. The light receiving optical axis is deflected by the beam splitter to intersect with the projection optical axis, allowing the optical system to achieve the required focal length while reducing the overall instrument size and weight.
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 allows for a shorter optical axis length than the focal length of the lens group, enabling the miniaturization of the electronic distance measuring instrument while maintaining measurement accuracy and stability.
Implementation Method 1
a projection optical axis deflecting unit for deflecting the projection optical axis so that the projection optical axis coincides with the light receiving optical axis
Implementation Method 2
a first light receiving optical axis deflecting unit for deflecting the light receiving optical axis toward the second light receiving optical axis deflecting unit
Implementation Method 3
a second light receiving optical axis deflecting unit for deflecting the light receiving optical axis toward the photodetector
Implementation Method 4
an incident light is arranged to focus on a light receiving surface by a refraction action of the lenses
Data Source
Figure 1~2B
Figure 3~4
Figure 5~6
AI summary
The invention provides an electronic distance measuring instrument, which comprises a light projecting optical system for emitting a distance measuring light onto a distance measuring optical axis and a light receiving optical system for leading a reflected distance measuring light to a photodetector, wherein the light projecting optical system has a projection optical axis deflecting unit for deflecting a projection optical axis so that the projection optical axis coincides with a light receiving optical axis, the light receiving optical system has a first light receiving optical axis deflecting unit and a second light receiving optical axis deflecting unit which are arranged on a same plane, the photodetector is arranged on a plane different from the first light receiving optical axis deflecting unit and the second light receiving optical axis deflecting unit.