Optical device, projector, manufacturing method, and manufacturing support apparatus

An optical device comprising:

• a liquid crystal cell that transmits laser light that is in a state of polarization of a given direction and of a given wavelength, the liquid crystal cell being capable of shifting a direction of a director with respect to the given direction by rotating the direction of the director parallel to a substrate surface;
• a wave plate that transmits laser light emitted from the liquid crystal cell, the wave plate having a phase delay axis set in an arbitrary direction;
• and
• a control circuit that cyclically shifts the direction of the director, wherein
• the optical device outputs the laser light that has passed through the wave plate and the liquid crystal cell,
• the laser light includes a plurality of beams of laser light differing in wavelength, and
• a thickness of the liquid crystal cell is adjusted to a thickness that causes a laminated wave plate composed of the wave plate and the liquid crystal cell to operate, in a vicinity of each of the differing wavelengths, as a half wave plate.

A manufacturing method of an optical device that includes a liquid crystal cell that transmits a plurality of laser light beams that are in a state of polarization of a given direction and have differing wavelengths, the liquid crystal being capable of shifting a direction of a director with respect to the given direction, the optical device further including a wave plate that has a phase delay axis set in an arbitrary direction and that transmits the laser light that has passed through the liquid crystal cell, the optical device outputting the laser light that has passed through the wave plate and the liquid crystal cell, the manufacturing method comprising:

• a first determining step of determining a thickness of the liquid crystal cell;
• a second determining step of determining an angle between a phase delay axis of the wave plate and a phase delay axis of the liquid crystal cell;
• and
• a third determining step of determining based on the thickness of the liquid crystal cell determined at the first determining step and on the angle between the phase delay axes determined at the second step, a thickness of the wave plate to be a thickness that causes a laminated wave plate composed of the wave plate and the liquid crystal cell to work as a quarter wave plate for respective wavelengths of emitted beams of light.

A manufacturing method of an optical device that includes a liquid crystal cell that transmits a plurality of laser light beams that are in a state of polarization of a given direction and have differing wavelengths, the liquid crystal being capable of shifting a direction of a director with respect to the given direction, the optical device further including a wave plate that has a phase delay axis set in a predetermined direction and that transmits the laser light that has passed through the liquid crystal cell, the optical device outputting the laser light that has passed through the wave plate and the liquid crystal cell, the manufacturing method comprising:

• a first determining step of determining a thickness of the wave plate;
• a second determining step of determining an angle between a phase delay axis of the wave plate and a phase delay axis of the liquid crystal cell;
• and
• a third determining step of determining based on the thickness of the wave plate determined at the first determining step and on the angle between the phase delay axes determined at the second step, a thickness of the liquid crystal cell to be a thickness that causes a laminated wave plate composed of the wave plate and the liquid crystal cell to work as a half wave plate for respective wavelengths of emitted beams of light.