The Technical Committee TC 1-95 established in the International Commission on Illumination (CIE) is currently active in improving the CIE whiteness formula to extend the scope of the applicability of lighting conditions other than the standard illuminant D65. However, it is important to examine whether or not the CIE whiteness formula is significantly superior to other whiteness formulas under the standard illuminant D65. In this study, we conducted comparisons of the predictive performance of 19 whiteness formulas, including the CIE whiteness formula. These comparisons were based on the results of nine visual evaluation experiments that were conducted by four research groups. The results of the analysis clearly demonstrated that, compared to the CIE whiteness formula, the Uchida and Grum whiteness formulas had better outcomes. The predictive performance of the CIE whiteness formula was ranked 11th among the 19 whiteness formulas. This low predictive performance is due to the structure of the CIE whiteness formula, which does not have a penalty term. We also found that the structure of the Grum whiteness formula was simpler and had better predictive performance than the Uchida whiteness formula. Thus, we conclude that the Grum whiteness formula is superior to the Uchida whiteness formula.

Advances of lighting technology make it possible to realize various types of space lighting from strongly directional to highly uniform. In this study, the effect of mixture ratio of directional and diffused light on KANSEI evaluations of the object and scene, black lacquer bowl with tofu sample in nearly uniform and achromatic background is investigated. Subjective evaluations were carried out under various lighting conditions using 15 adjective pairs, such as “Non-glossy vs Glossy”, “Soft vs Hard”, and “Ugly vs Beautiful”, etc., that were selected in the pre-experiment. Results of the subjective evaluation for the adjective pairs are divided into 3 groups in relation to lighting quality. Group 1 that reflect surface property of the object such as “Non-glossy vs Glossy”, correlate primarily to highlight luminance with mild correlation to the luminance of non-highlight area, whereas those of Group 2 that reflect nonvisual physical properties such as “Soft vs Hard”, correlate primarily to the luminance of non-highlight area with almost no effect from directional light. Adjective pairs of Group 3 that reflect to higher order values of object and/or scene such as “Cheap vs Luxury” or “Realistic vs Fantastic”, correlate strongly to the luminance contrast between highlight and non-highlight areas.

An alternative estimation of the dissipated power allocation in OLED based on the analysis of the transverse propagating electromagnetic (EM) waves along the layers of the OLED is proposed. The dissipated power mode fraction has been conventionally defined by dividing the normalized in-plane wavevector with the cut-off of the transvers propagation, which is equal to the refractive index of the each layer, according to the ray-optical sense. Instead, we adopt the propagating EM eigenmode in OLED, physically confining a piece of the power in the thin film layers. The spectral integral is described as the extension of Cauchy’s principal value integral at the eigenvalue of the in-plane wavevector of the EM propagating mode along the layers; and is derived to the product of the peak value of the spectral distribution and the imaginary part of the eigenvalue of the in-plane wavevector multiplied by π, with the aid of the self-consistent scheme. For the simple model of two layers between semi-infinite substrate and metal, the present estimation is closer than the conventional one to the quantitative grasping the dipole radiation’s allocation into the extraction and the confinement.