Fresnel lens sheet, rear projection screen and rear projection display

A Fresnel lens sheet comprising:

• a Fresnel lens having an entrance surface provided with a plurality of total reflection Fresnel lens elements;
• and
• a base sheet having an exit surface;
• wherein each of the total reflection Fresnel lens elements has a light-receiving facet on which image light falls, and a total-reflection facet that totally reflects the image light fallen on the light-receiving facet toward the exit surface, and
• horizontal length L2 (mm) of the base sheet, thickness T2 (mm) of the base sheet and maximum elongation percentage A2 (%) of the base sheet at which the base sheet lengthens due to moisture absorption of the base sheet, meet a requisite condition expressed by a relational expression:
• A2≦0.6T2/L2.

A rear projection screen comprising:

• a Fresnel lens sheet having an entrance surface and an exit surface, the entrance surface being provided with a plurality of total reflection Fresnel lens elements;
• and
• a lenticular lens formed on the exit surface of the Fresnel lens sheet;
• wherein each of the total reflection Fresnel lens elements has a light-receiving facet on which image light falls, and a total-reflection facet that totally reflects the image light fallen on the light-receiving facet toward the exit surface, and
• horizontal length L1 (mm) of the Fresnel lens sheet, thickness T1 (mm) of the Fresnel lens sheet and maximum elongation percentage A1 (%) of the Fresnel lens sheet at which the Fresnel lens sheet lengthens due to moisture absorption of the Fresnel lens sheet, meet a requisite condition expressed by a relational expression:
• A1≦0.6T1/L1.

A rear projection screen comprising:

• a Fresnel lens sheet comprising a Fresnel lens having an entrance surface provided with a plurality of total reflection Fresnel lens elements, and a base sheet having an exit surface;
• and a lenticular lens formed on the exit surface of the Fresnel lens sheet;
• wherein each of the total reflection Fresnel lens elements has a light-receiving facet on which image light falls, and a total-reflection facet that totally reflects the image light fallen on the light-receiving facet toward the exit surface, and
• horizontal length L2 (mm) of the base sheet, thickness T2 (mm) of the base sheet and maximum elongation percentage A2 (%) of the base sheet at which the base sheet lengthens due to moisture absorption of the base sheet meet a requisite condition expressed by a relational expression:
• A2≦0.6T2/L2.

A rear projection display comprising a rear projection screen comprising

• a Fresnel lens sheet having an entrance surface and an exit surface, the entrance surface being provided with a plurality of total reflection Fresnel lens elements;
• and
• a lenticular lens formed on the exit surface of the Fresnel lens sheet;
• wherein each of the total reflection Fresnel lens elements has a light-receiving facet on which image light falls, and a total-reflection facet that totally reflects the image light fallen on the light-receiving facet toward the exit surface, and
• horizontal length L1 (mm) of the Fresnel lens sheet, thickness T1 (mm) of the Fresnel lens sheet and maximum elongation percentage A1 of the Fresnel lens sheet (%) at which the Fresnel lens sheet lengthens due to moisture absorption of the Fresnel lens sheet, meet a requisite condition expressed by a relational expression:
• A1≦0.6T1/L1.

A rear projection display comprising a rear projection screen comprising

• a Fresnel lens sheet having an entrance surface provided with a plurality of total reflection Fresnel lens elements;
• and a base sheet having an exit surface, and
• a lenticular lens formed on the exit surface of the Fresnel lens;
• wherein each of the total reflection Fresnel lens elements has a light-receiving facet on which image light falls, and a total-reflection facet that totally reflects the image light fallen on the light-receiving facet toward the exit surface, and
• the horizontal length L2 (mm) of the base sheet, thickness T2 (mm) of the base sheet and maximum elongation percentage A2 (%) of the base sheet at which the base sheet lengthens due to moisture absorption of the base sheet, meet a requisite condition expressed by a relational expression:
• A2≦0.6T2/L2.