TEST IMAGE DISPLAY BODY, CHARACTERISTIC INDEX VALUE CALCULATION SYSTEM AND CHARACTERISTIC INDEX VALUE CALCULATION METHOD

To provide a test image display body for evaluating an optical characteristic of a light control sheet, and a characteristic index value calculation method.SOLUTION: A test image a test image display body displays consists of: three first straight lines 11A; three second straight lines 11B; and three third straight lines 11C, in which the straight lines do not intersect mutually. The first straight lines 11A extend a tangential direction of a first circle internally contacting with the three first straight lines 11A, and are equally disposed in a circumferential direction of the first circle. The second straight lines 11B internally contact with the three second straight lines, extend a contact line direction of a second circle concentric with the first circle, and are equally disposed in a circumferential direction of the second circle so that the second straight lines 11B are located one by one among the mutually adjacent first straight lines 11A in the circumferential direction of the second circle. A diameter of the first circle is shorter than that of the second circle, and the third straight lines 11C are located outward in a radial direction of the second circle, and located on a normal line of the first straight lines 11A.SELECTED DRAWING: Figure 3 【課題】調光シートが有する光学特性を評価するための試験画像表示体、および特性指標値算出方法を提供する。【解決手段】試験画像表示体が表示する試験画像は、相互に交差しない直線であって、３本の第１直線１１Ａと、３本の第２直線１１Ｂと、３本の第３直線１１Ｃとから構成され、第１直線１１Ａは、３本の第１直線１１Ａに内接する第１円の接線方向に延び、かつ、第１円の周方向に等配される。第２直線１１Ｂは、３本の第２直線に内接し、かつ第１円と同心の第２円の接線方向に延び、第２円の周方向において相互に隣り合う第１直線１１Ａの間に１本ずつ第２直線１１Ｂが位置するように、第２円の周方向に等配される。第１円の直径は、第２円の直径よりも短く、第３直線１１Ｃは、第２円の径方向における外側に位置し、かつ第１直線１１Ａの法線上に位置する。【選択図】図３