SEP1A / SEP2A Series: Ultra-high CRI LEDs to Provide High Quality Lighting

Sanken’s LEDs Will Let Your Lighting Fixtures Achieve Performance Same as AAA Fluorescent Lamps for Color Evaluation

Introduction Video: Ultra-high CRI LEDs (1 min 54 s)

The SEP1A/SEP2A series are high color rendering LED devices that have performance quality defined by not only the average color rendering index, Ra, but also the special color rendering index, Ri. By using our LED devices, you can realize lighting equipment with the same performance as color rendering AAA fluorescent lamps commonly used for color evaluation.
The SEP1A series, developed with our own color rendering enhancement technologies, can maintain the industry’s highest(1) luminous efficacy while achieving high color rendering. This leads to the energy-saving effect(2) over 2 times higher than color rendering AAA fluorescent lamps. According to these advantages, you can also use them as light sources for lighting equipment which require high color rendering such as task lighting, museum lighting, and so on.
In addition, our LED devices suppress ultraviolet components and thus promise preventive effects against discoloration of exhibits.

(1) Based on our survey as of March 28, 2022.
(2) Depends on the designs of lighting fixtures.

Product Lineup offering LEDs with Wide-range CCTs

Application Examples: Office Lighting, Color Evaluation Lighting, etc.


  • High color rendering to faithfully reproduce true colors
     CCT of 5000 K: Ra = 95 (typ.), Ri = 90 (typ.)
     CCT of other values: Ra = 90 (typ.), Ri = 90 (typ.)
  • Product lineup to offer LEDs with wide-rage CCTs: 2700 K to 12000 K
  • High luminous efficacy (ex.: SEP2AQ1L92, 141 lm/W)


・For ceiling lights, downlights, indirect lighting, etc.
     Household lighting, office lighting, commercial lighting
・For industries incl. textile, printing, manufacturing, etc.
      Inspection lighting, evaluation lighting
・For shooting light sources etc.
     Floodlights, ring lights


 ・Dimensions (L×W×H):2.8 × 3.5 × 0.7 mm
 ・Image: Physical dimensions (.png)
 ・Bare lead frame: Pb-free
 ・Highly heat-dissipating: θ(J-S) = 25 °C/W

SEP1A Series (under development)

(Condition: IF = 50 mA, TA = 25 ℃)
Part Number /
Data Sheet
Color Temp.
CCT (Typ.)
Luminous Flux
Φv (Typ.)
Luminous Efficacy
η (Typ.)
Fwd. Voltage
VF (Typ.)
Avg. Color
Rendering Index
Sp. Color
Rendering Index
SEP1AQ1L92LL 5000 K(3)19.6 lm145 lm/W2.71 V  ≥95  (3)   ≥90  (3)
SEP1AQ1L92SS 19.6 lm140 lm / W2.81 V

(3) Refers to the characteristic value when the two LEDs are used in combination; equivalent to the High Color Rendering Type AAA, Class 4, defined in JIS Z 9112.

SEP2A Series (under development)

(Condition: IF = 30 mA, TA = 25 ℃)

Part NumberColor Temp.
Luminous Efficacy
Fwd. Voltage
Avg. Color Rendering Index
Sp. Color Rendering Index
SEP2AQ1L925000 K141 lm/W5.5 V  95  (4)   90  (4)
SEP2AL1L922700 K124 lm/W
SEP2AE1L92 (In Prep.)4000 K136 lm/W
SEP2AM1L92 (In Prep.)6500 K139 lm/W
SEP2AD1L9212000 K131 lm/W

(4) Ra ≥ 95 and Ri ≥ 90 when CCT = 5000 K.

If you need to request samples or have any questions, please feel free to contact us using the form below.

Ultra-high Color Rendering Enhancement Technologies Used in Our LEDs

Figure 1. Spectra of Reference Light Source vs. White LED

Figure 2. Color-matching Functions

Figure 3. Difference in Color Rendering Enhancement Methods

There is a trade-off between color rendering and luminous efficacy.
For example, the reference light source equivalent to sunlight (Figure 1) can yield higher color rendering with its flattened spectrum. Which means, however, it requires many types of phosphors to do so. The more the phosphor types are used, the less the light conversion efficiency becomes, thus resulting in lower luminous efficacy.

To improve this trade-off, we have developed the following technologies:

  • By adding the algorithms of the color-matching functions (Figure 2) that represent human color perception to our simulator, we optimized excitation lights and the compositions of phosphors. This allowed us to improve the trade-off between color rendering and luminous efficacy.
          Ultra-high color rendering that brings in excellent CRI scores including Ri and comes in wide-range color temperatures
          CCT of 5000 K: Ra ≥ 95, Ri ≥ 90
           CCT of other values: Ra = 90 (typ.), Ri = 90 (typ.)
  • By using blue LED chips with long wavelengths for excitation lights, we finally raised the light conversion efficiency in the phosphors used. We also utilized the transmitted lights to yield higher luminous efficacy.
          141 lm/W (SEP2AQ1L92)

This long-wavelength blue LED chip strategy also have succeeded in suppressing ultraviolet components. With the UV-component-suppressing effect, our LEDs can emit the lights that prevent exhibits from discoloring (Figure 3).

LEDs Attained to the Standards Recommended by the Domestic Printing Society—Ideal Color Rendering for Color Evaluation

Color rendering describes how a light source can render colors appear when it illuminates an object.
A color rendering index (CRI) is the metric to measure this color rendering performance.
A CRI score represents the color appearance when an object is lit by sunlight (i.e., reference light source) on a scale of up to 100. And there are two types of CRI: Ra, average color rendering index, determined by the average value of neutral-color-based test color samples (R1 to R8); Ri, special color rendering index, determined by each value of test color samples including primary colors (R9 to R15).

In general, the CRI score is expressed by a Ra value; however, even with high Ra values, most light sources have less color reproducibility due to their low Ri values (the primary-color-based metric). For this reason, we sought the way to bring out higher Ri values in the SEP1A/SEP2A series.
Our efforts on the SEP1A/SEP2A series then turned out to be extremely great—Ra of 95 (typ.) and Ri of 90 (typ.)—high color rendering.

Especially when it comes to our LED devices with 5000 K (the SEP1A series and SEP2AQ1L92), they satisfied the standards recommended by the Japanese Society of Printing Science and Technology and got high enough levels as well as color rendering AAA fluorescent lamps (see the table below), which are commonly used for color evaluation.
So, our LED devices will best suit a light source for color inspection as they faithfully reproduces a wide range of colors, including primary colors.

Measured Value Comparison: JSPST*-recommended Std vs. AAA Fluorescent Lamp vs. SEP1A Series

Ultra-high Color Rendering and Wide-range Product Lineup—Applicable to Wellness Lighting

Various Combinations Available as We Offer LEDs with Wide-range CCTs

In recent years, human-friendly lighting dedicated to better light qualities has become widespread from a standpoint of wellness(5) and HCL(6).

[Lighting Application Examples]

  • Lighting that changes its color and brightness along with the time-course changes of natural sunlight
  • Lighting equipment that can adjust tones and tints unlimitedly
  • Lighting that sets a healthy circadian rhythm by exploiting the nature of biological body-to-light synchronization

The SEP2A series provides a wide range of color temperatures, from 2700 K to 12000 K.
Combining the LEDs of different color temperatures will help you design color-tunable lighting systems to meet any situations.

(5) Wellness: A lifestyle that people seek to live better; the term interpreted in a broader sense than the term “health” defined by WHO.
(6)HCL (Human Centric Lighting): A type of lighting that supports people’s health with its safety, comfort, and convenience.
(Source page available only in Japanese: Japan Lighting Manufacturers Association,

Ultra-high Color Rendering and High Efficiency—Applicable to Color Inspection Lighting

With the characteristics attained to the standards recommended by the Japanese Society of Printing Science and Technology, the SEP1A series enables you to realize an LED-based lighting system, in which color rendering AAA fluorescent lamps have typically been used for color evaluation.

Having a luminous efficacy of 140 lm/W, the SEP1A series also offers you an industry-leading performance(1) and contributes to the energy-saving effect(7) over 2 times higher than the color rendering AAA fluorescent lamps.

For the light sources used in inspection environments such as color evaluation—where color reproducibility plays a key role—our LEDs will be your best possible choice.

(7) Depends on the designs of lighting fixtures.

Color Appearance Comparison: AAA Fluorescent Lamp vs. SEP1A Series

Near-natural but Discoloration-proof Light—Applicable to Exhibition Lighting

A short-wavelength blue component contained in a color rendering AAA fluorescent lamp can induce exhibits to discolor.

In contrast, the SEP1A/SEP2A series employs the long-wavelength blue LED chips through our own color rendering enhancement technologies. This helps our LEDs remain at high color rendering and emit a discoloration-preventive light.

You will easily see how our LEDs outperform when they are applied to the lighting equipment for exhibits like photographs and artworks. They can not only reproduce the true colors of exhibits faithfully but also prevent discoloration more than any of color rendering AAA fluorescent lamps.

If you need to request samples or have any questions, please feel free to contact us using the form below.

Related Articles

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▶Customization to Provide the Desired Lighting for Each Scene
Sanken’s own color-tuning technology is here for custom LEDs best suited to your needs.

Questions or Comments?

Please feel free to contact us if you cannot find the desired product from the lineup.