A manufacturing method for a batch-molding multi optical transmission sheet assembly, comprising:
- housing, in a disposition hole of a housing member, one end part of a batch-molding multi optical transmission sheet including:
- a sheet-like covering part made of plastic;
- and
- a plurality of optical transmission regions, inside the sheet-like covering part, including a core region made of plastic that is disposed to extend along an extending direction of the sheet-like covering part and a clad region made of plastic that surrounds an outer circumference of the core region, the optical transmission regions being arranged in a line substantially parallel with each other along a principal surface of the sheet-like covering part;
- and
- fixing the batch-molding multi optical transmission sheet and the housing member.