New Brightness (Color) Sensor Optimized for Smartphones

Industry-leading infrared cutoff function provides greater enclosure design flexibility

WSON008X2120 ROHM Color Sensor BH1745NUC

Kyoto, Japan and Santa Clara, Calif. – Feb. 5, 2015 – ROHM Semiconductor has recently announced the development of a color sensor for display-equipped devices such as smartphones and tablets capable of detecting the color temperature, brightness, and RGB components of ambient light.

The BH1745NUC leverages original infrared removal technology and computing methods to achieve the industry's highest* infrared cutoff characteristics, reducing the effects of infrared rays by over 10x compared with conventional products. This enables compatibility with dark (low permeability) optical windows – unlike conventional color sensors that cannot provide accurate detection due to the effects of infrared interference when dark windows are used.

In recent years a greater number of smartphones, tablets, and other display-equipped devices have begun to integrate color sensors in order to analyze the RGB components of ambient light for display image adjustment or perform backlight dimming based on the surrounding brightness levels.

Conventional color sensors require a transparent optical window in order to accurately detect visible (i.e. RGB) light. However, the design trend in many smartphones and portable devices is to adopt dark optical windows, which although are more stylish make it difficult to precisely detect colors, since less visible light gets through and the light that does permeate gets mixed in with IR rays.

In response, ROHM takes advantage of optical sensor expertise cultivated over many years, including original infrared removal technology and proprietary computing methods, to develop a color sensor that provides unmatched performance – even with dark optical windows.

*According to a December 17, 2014 ROHM study

Pricing: US$0.72 (4000 pcs)
Availability: Now

Improved Enclosure Design Spectral Sensitivity Characteristics

Key Features
Compatibility with dark optical windows provides greater design flexibility Industry-leading infrared cutoff characteristics reduce the effects of IR rays by more than 10x compared with conventional products. This provides greater design freedom by enabling support for even dark optical windows. ROHM's new color sensor is capable of filtering only the spectrum of visible light in order to perform more accurate brightness and color temperature calculations based on ambient conditions


  • Display-equipped devices such as smartphones and tablets
    • Analyzes the RGB components of ambient light and detects the color temperature for adjusting display images
    • Detects the brightness for optimized LED backlight dimming in displays based on surrounding conditions
  • Industrial equipment and processing facilities that detect the color of products and/or liquids


Color Temperature and Brightness Detection Comparison


About ROHM Semiconductor:
ROHM Semiconductor is an industry leader in system LSI, discrete components and module products, utilizing the latest in semiconductor technology. ROHM's proprietary production system, which includes some of the most advanced automation technology, is a major factor in keeping it at the forefront of the electronic component manufacturing industry. In addition to its development of electronic components, ROHM has also developed its own production system so that it can focus on specific aspects of customized product development. ROHM employs highly skilled engineers with expertise in all aspects of design, development and production. This allows ROHM the flexibility to take on a wide range of applications and projects and the capability to serve valuable clients in the automotive, telecommunication and computer sectors, as well as consumer OEMs.