Patent ID: 11921377
Assignee: SHARP DISPLAY TECHNOLOGY CORPORATION
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An optical element comprising:
a liquid crystal cell including a first substrate, a liquid crystal layer, and a second substrate; and
a quarter-wave film,
the liquid crystal layer containing liquid crystal molecules twist-aligned between the first substrate and the second substrate,
the liquid crystal cell including, in at least one of the first substrate or the second substrate, electrodes for voltage application to the liquid crystal layer,
the electrodes disposed to enable switching between a first state and a second state by application of voltage to the liquid crystal layer, the first state aligning the liquid crystal molecules near the first substrate in a first alignment direction, the second state aligning the liquid crystal molecules near the first substrate in a second alignment direction perpendicular to the first alignment direction in a plan view,
the switching between the first state and the second state controlling a polarization state of light incident on the liquid crystal cell,
wherein circularly polarized light incident on the liquid crystal cell is converted to first linearly polarized light in the first state, while in the second state, converted to second linearly polarized light whose polarization direction is perpendicular to a polarization direction of the first linearly polarized light in a plan view, and
wherein linearly polarized light incident on the liquid crystal cell is converted to first circularly polarized light in the first state, while in the second state, converted to second circularly polarized light whose rotation direction is reverse to a rotation direction of the first circularly polarized light.