Optical observation unit and method for ensuring an unchanging illumination intensity when changing the color temperature of the illumination
US-9829692-B2 · Nov 28, 2017 · US
Neutral density filters
Neutral density filters · Cooperative Patent Classification (CPC)
Computing, optics, measurement, and control technologies.
Related technology areas
Mapped technology topics for this CPC code.
| Metric | Value |
|---|---|
| CPC code | G02B5/205 |
| Official title | {Neutral density filters} |
| Display label | Neutral density filters |
| Total patents | 337 |
Filing trend
Year-over-year patent counts classified under this CPC code.
Filing activity over the last five years is declining.
| Year | Patents |
|---|---|
| 2015 | 25 |
| 2016 | 22 |
| 2017 | 45 |
| 2018 | 36 |
| 2019 | 30 |
| 2020 | 24 |
| 2021 | 35 |
| 2022 | 34 |
| 2023 | 34 |
| 2024 | 24 |
| 2025 | 22 |
| 2026 | 6 |
Representative patents
Representative publications under this CPC code from precomputed stats, or recent filings when stats are unavailable.
Head-mounted display device
US-2017261656-A1 · Sep 14, 2017 · US
Adjustable color correction for automated high intensity stage lights
US-9759845-B2 · Sep 12, 2017 · US
Laser beam stop elements and spectroscopy systems including the same
US-9759655-B2 · Sep 12, 2017 · US
Optical element, optical system and imaging apparatus
US-9654676-B2 · May 16, 2017 · US
Color filter and preparation method thereof, and display device
US-9651794-B2 · May 16, 2017 · US
Transparent organic light emitting display device
US-2017125744-A1 · May 4, 2017 · US
Display unit and electronic apparatus
US-2017097452-A1 · Apr 6, 2017 · US
Transparent Plate and Substrate Processing System Therewith
US-2017076965-A1 · Mar 16, 2017 · US
Tube-type lens, optical emission spectroscopy (oes) apparatus including the tube-type lens, plasma monitoring system including the oes apparatus, and method of manufacturing semiconductor device by using the plasma monitoring system
US-2017067779-A1 · Mar 9, 2017 · US
Optical filter and optical apparatus
US-9588266-B2 · Mar 7, 2017 · US
Imaging sensor coupled with layered filters
US-2017041574-A1 · Feb 9, 2017 · US
Array substrate and method of manufacturing the same, display panel and method of manufacturing the same, and display device
US-9553112-B2 · Jan 24, 2017 · US
Array substrate and method of manufacturing the same, display panel and method of manufacturing the same, and display device
US-2016372491-A1 · Dec 22, 2016 · US
Three-dimensional image display method and three-dimensional image display device
US-2016366400-A1 · Dec 15, 2016 · US
Optical filter and optical apparatus
US-9513417-B2 · Dec 6, 2016 · US
Printed appliqué and method thereof
US-9488892-B2 · Nov 8, 2016 · US
Spectral Control System
US-2016305766-A1 · Oct 20, 2016 · US
Optical filter and method for preparing same
US-2016291222-A1 · Oct 6, 2016 · US
Light amount adjusting device, lens barrel, and image capturing apparatus
US-2016259100-A1 · Sep 8, 2016 · US
Frequently asked questions
Answers are generated from the same data shown on this page.
- What is CPC G02B5/205?
- CPC G02B5/205 is the Cooperative Patent Classification code for “Neutral density filters.”
- How many patents are filed under CPC G02B5/205 (Neutral density filters)?
- Our database includes 337 publications tagged with this CPC code.
- Is patent activity under CPC G02B5/205 growing?
- Publication counts under this code: 24 in 2024 vs 22 in 2025 (latest complete years).