Telephotometer Light Meter with Variable Iris and Range Finder
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Solution Overview
Problem
Current light measurement technologies are unable to conveniently measure light intensity from a distant light source, leading to challenges in regulating spillover and trespass light, which can cause discomfort, health issues, and aesthetic problems, and there is a lack of equipment that can perform field measurements of light intensity, luminance, and illuminance effectively.
Innovation Solution
A portable light meter system that includes a telephotometer with a variable iris diaphragm and a range finder, allowing for the measurement of light intensity, luminance, and illuminance from a distant light source, with the ability to adjust the field of view and calculate light intensity using the inverse square law, enabling field measurements of light quantities such as candelas per steradian.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a traditional light meter is placed directly on a surface to measure illuminance, then the measurement of light intensity can be obtained, but the measurement cannot be performed from a distant location and requires direct contact with the surface being measured
Solution Approach 1:
The patent transitions from surface-based illuminance measurement to distance-based intensity measurement by incorporating a range finder. This adds the dimension of distance measurement, allowing the device to calculate light intensity (candelas) from a remote location rather than requiring contact with the illuminated surface.
Solution Approach 2:
The patent introduces an optical system with lens and photo detector as an intermediary between the distant light source and the measurement apparatus. This optical train captures light from the distant source and focuses it onto the photo detector, enabling remote measurement without direct surface contact.
2Measurement precision
If a telephotometer is used to measure luminance from a distant source, then the field of view can be focused on the light source, but the device cannot simultaneously measure distance to calculate light intensity
Solution Approach 1:
The patent combines a telephotometer optical system with a range finder and processor into a single integrated device. This merger enables the apparatus to simultaneously perform luminance measurement, distance measurement, and light intensity calculation, providing versatility in measuring multiple photometric quantities from a single instrument.
3Illumination intensity
If outdoor lighting is increased to improve visibility and safety, then lighting performance is enhanced, but spillover and trespass light cause discomfort and health issues to nearby areas
Solution Approach 1:
The patent enables measurement of light intensity at specific locations and distances from light sources. This data can feed back into lighting design and regulation processes, allowing optimization of lighting configurations to achieve desired illumination levels while minimizing spillover and trespass light effects on surrounding areas.
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
Enables accurate and convenient field measurements of light intensity and related quantities, facilitating the regulation of spillover and trespass light, improving quality of life and compliance with lighting regulations by providing a portable device capable of measuring light from a single luminaire or multiple fixtures at varying distances.
Implementation Method 1
a telephotometer having an objective lens and a photo detector
Implementation Method 2
a telephotometer having an objective lens mounted at one end of a longitudinal body
Implementation Method 3
a photo detector having a data output communication conduit, the photo detector being mounted to receive light energy entering the telephotometer
Implementation Method 4
a range finder longitudinally aligned with the telephotometer
Data Source
AI summary
A light meter for measuring photometric quantities includes a telephotometer having a photo detector to receive light energy entering the telephotometer. A light metering valve, for the purpose of providing a variable field of view, is located in the body of the telephotometer generally at the focal plane of the objective lens of the telephotometer. A controller, which includes a digital processor in communication with the photo detector will process information from the photo detector and from a range finder included in the system to output light intensity of a target light source.