Polarization conversion element, projector, and method for manufacturing polarization conversion element

A method for manufacturing a polarization conversion element, the method comprising:

• a polarization separation film formation step of forming a polarization separation film on a first surface of a first substrate that has the first surface and a second surface parallel to each other and serves as a base of a first light transmissive substrate;
• a reflection film formation step of forming a reflection film on the second surface of the first substrate;
• a plasma polymerization film formation step of forming a plasma polymerization film on a surface of the polarization separation film;
• an activation step of activating the plasma polymerization film on the first substrate;
• a first bonding step of bonding the activated plasma polymerization film to a second surface of a second substrate that has a first surface and the second surface parallel to each other and serves as a base of a second light transmissive substrate to form a first block formed of the first substrate and the second substrate integrated with each other;
• an adhesive layer formation step of sequentially forming adhesive layers on a plurality of the first blocks, the adhesive layer bonding the first surface of the second substrate that forms one of the first blocks to the reflection film on the first substrate that forms another one of the first blocks;
• a second bonding step of bonding the adhesive layers to each other by curing to form a second block formed of the plurality of the first blocks integrated with each other;
• and
• a cutting step of cutting the second block at a predetermined angle with respect to the first surfaces and the second surfaces to form a stacked block having a light incident surface and a light exiting surface parallel to each other.

A method for manufacturing a polarization conversion element, the method comprising:

• a polarization separation film formation step of forming a polarization separation film on a second surface of a second substrate that has a first surface and the second surface parallel to each other and serves as a base of a second light transmissive substrate;
• a plasma polymerization film formation step of forming a plasma polymerization film on a surface of the polarization separation film;
• a reflection film formation step of forming a reflection film on a second surface of a first substrate that has a first surface and the second surface parallel to each other and serves as a base of a first light transmissive substrate;
• an activation step of activating the plasma polymerization film on the second substrate;
• a first bonding step of bonding the activated plasma polymerization film to the first surface of the first substrate to form a first block formed of the first substrate and the second substrate integrated with each other;
• an adhesive layer formation step of sequentially forming adhesive layers on a plurality of the first blocks, the adhesive layer bonding the reflection film on the first substrate that forms one of the first blocks to the first surface of the second substrate that forms another one of the first blocks;
• a second bonding step of bonding the adhesive layers to each other by curing to form a second block formed of the plurality of the first blocks integrated with each other;
• and
• a cutting step of cutting the second block at a predetermined angle with respect to the first surfaces and the second surfaces to form a stacked block having a light incident surface and a light exiting surface parallel to each other.