1999 Fiscal Year Final Research Report Summary
Evaluation Method for Viewing Angle of LCDs based on Overall Picture Quality
| Project/Area Number |
10835009
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
感性工学
|
|---|
| Research Institution | Shizuoka University |
|---|
Principal Investigator |
SHIMODAIRA Yoshifumi Faculty of Engineering, Shizuoka University, Professor, 工学部, 教授 (30022247)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
OHASHI Gosuke Faculty of Engineering, Shizuoka University, Research Associate, 工学部, 助手 (80293603)
|
|---|
| Project Period (FY) |
1998 – 1999
|
| Keywords | LCD / Viewing Angle / Picture Quality / Subjective Evaluation Experiments / Model of Summation of Picture Quality Impairment / Optical Characteristic / Individual Picture Quality / Overall Picture Quality |
|---|
| Research Abstract |
A Liquid Crystal Display (LCD) generally has the features that picture quality is degraded as an observation angle becomes large. This is called the viewing angle characteristics of an LCD. The viewing angle of an LCD is currently defined only in terms of contrast. The definition of that is insufficient for evaluating the viewing angles characteristics of an LCD because picture quality is affected by contrast but also luminance, gamma and color. There is, however, no sufficient method for the evaluation of viewing angle when degradation of picture quality is caused by the plural factors listed above. Therefore, the viewing angle characteristics should be defined on the bases of overall picture quality.
The purpose of this study is to establish an evaluation method of overall picture quality for pictures displayed on an LCD when the observation angle changes. In order to estimate the overall picture quality when the plural factors change simultaneously, optical characteristics of an LCD were measured as a function of an observation angle. The overall picture quality was obtained on the basis of the model of summation of picture quality impairment and calculated using individual picture quality evaluated last year when each of factors of gamma, contrast, luminance and color respectively changed. Furthermore, to verify the effectiveness of this proposed evaluation method of the viewing angle; we carried out direct subjective evaluation of overall picture quality by changing observation angle. As a result, both viewing angles based on the acceptable limit of picture quality estimated by the proposed method and evaluated by the direct subjective evaluation of picture quality were similar. Therefore, the proposed evaluation method of viewing angle is found to be more effective for LCDs than currently used method, contrast criterion.
|
