Overview
IEC 62679-2:2018 - "Electronic paper display - Part 2: Essential ratings and characteristics" defines the essential ratings and characteristics for reflective electronic paper display (EPD) modules that can hold an image and may include an integrated lighting unit (ILU). The standard is intended to support specification sheets and product evaluation by specifying which optical, electro‑optical and environmental parameters should be reported and tested for EPD modules.
Key topics and requirements
The standard organizes the key technical content you should include when specifying or evaluating an EPD module:
- Scope: Restricted to reflective EPD modules capable of holding an image; ILUs are covered via associated measurement guidance.
- Classification: Required classifiers such as pixel layout (segment/dot matrix), driving circuit (passive/active), driving method (voltage/current), and display mechanism (e.g., electrophoretic, cholesteric, electrochromic, electrofluidic).
- Panel components and construction: Front plane, imaging layer, backplane, peripheral units (lighting, touch), substrate materials (rigid/flexible), connection designs (ZIF/LIF, ACF, COG, COF, FPC), and dimensional drawing elements (overall size, active area, pixel pitch, resolution).
- Input/output terminals: Pin identification and connection types (power, input, output, Hi‑Z, NC).
- Limiting values (absolute maximum ratings): Operating/storage temperatures, supply voltages for display and logic, input signal voltages, soldering temperature/time to connectors.
- Electrical and optical characteristics: As summarized in Table 1 of the standard - supply voltages/currents, reflectance (white/black), contrast ratios (diffuse/direct, ambient indoor/outdoor, viewing‑direction values and angular performance), reflectance non‑uniformity, chromaticity (white, black, RGB), frame response time, image retention duration, image‑holding power, and rewriting energy. For EPDs with ILU, illumination should be reported (e.g., CIE illuminant D50 or D65) and measurement methods reference IEC 62679‑3‑1/3‑2/3‑3.
Applications and who uses it
IEC 62679‑2 is practical for:
- Display manufacturers preparing datasheets and product specifications for EPD modules.
- Test laboratories performing optical and electro‑optical evaluations and environmental testing.
- System integrators and OEMs selecting displays for e‑readers, electronic shelf labels, signage, industrial human‑machine interfaces, and low‑power displays.
- Procurement and quality teams defining acceptance criteria and verifying supplier claims.
- Standards writers and contract drafters using the specified headline of the specification sheet and minimal compliance requirements.
Related standards
Keywords: IEC 62679-2, electronic paper display, EPD, essential ratings, optical characteristics, electro-optical, reflectance, contrast ratio, viewing angle, chromaticity, specification sheet.
