Define the complete transparent assembly
A transparent installation includes the active panel or LED structure, glazing, bonding layers, frames, wiring and the scene behind it. Report the measurement boundary. Transmission of a bare panel and transmission of a finished laminated assembly describe different objects.
Open-area ratio describes unobstructed geometry. Optical transmittance describes the fraction of incident light transmitted under stated measurement conditions. These quantities are not interchangeable. Haze, reflections, angular behaviour and the distribution of opaque elements also affect the view through the assembly.
Account for the background in the image
A transparent emissive pixel adds light to the existing scene. In a simple transparent OLED presentation, a black image region reduces emitted light and reveals the background. It cannot optically darken that background without a separate light-blocking mechanism. Dark outlines in source artwork therefore need testing against the real scene.
A useful local model is Lobserved = Lemit + τLbackground + Lreflection, where all luminances refer to the same viewing direction and τ is an effective transmittance. This assumes a stable scene, approximately linear superposition and a suitable scalar transmission approximation. Colour-dependent transmission, glare and different background patches require a fuller evaluation.
Hypothetical background change
Assume τ = 0.4, reflected luminance of 5 cd/m², white emission of 300 cd/m² and black emission of 0. Against a uniform 100 cd/m² background, the white-to-black ratio is 345/45 ≈ 7.67. Against a 500 cd/m² background it becomes 505/205 ≈ 2.46. The assumed values illustrate the model and do not specify a VITREVIA product.
Design content around the viewing task
Choose text, line weights and bright shapes that remain distinct across the expected background. Map important information away from visually busy objects where possible. Test the combination of image and scene while the viewer moves. Increasing the filled white area can change both visual obstruction and the display's operating load.
If the design uses a rear shade or controlled object lighting, include its operation in the system brief. Document the desired appearance with the display on, displaying black, and powered off. Record the allowed difference between these states and the required visibility of objects behind the screen.
A repeatable scene matrix
- Background: light/dark, uniform/busy, stationary/moving.
- Lighting: front, rear, direct reflection and normal operating transitions.
- Viewer: near/far, normal/off-axis and moving where applicable.
- Content: smallest text, thin lines, saturated colours and large bright regions.
- Assembly: actual glass, mounting, cables, frame and any shade.
Preserve photographs of the setup with exposure information and retain the source content. Quantitative transmittance work should specify the selected measurement method; IDMS chapter 11 distinguishes transmission measurement geometries. Use the linked scene qualification guide for an installation-level record.
Sources and further reading
- LG Display: transparent OLED
- LG: black content and transparent OLED
- NISTIR 6738: ambient contrast, equation 4 (printed p. 2)
- IDMS v1.3: measurement-topic index
Calculations use the stated assumptions. Project procedures and acceptance limits must be defined for the supplied configuration.