An imaging device is presented for use in an imaging system capable of improving the image quality. The imaging device has one or more optical systems defining an effective aperture of the imaging device. The imaging device comprises a lens system having an algebraic representation matrix of a diagonalized form defining a first Condition Number, and a phase encoder utility adapted to effect a second Condition Number of an algebraic representation matrix of the imaging device, smaller than said first Condition Number of the lens system.

Embodiments disclose a light guide device including a projector including a lens disposed to emit light and a barrel coupled to the lens, a first substrate that guides the light emitted from the projector, a first diffraction element region that is disposed on the first substrate and receives the light, and a second diffraction element region disposed on the first substrate and spaced apart from the first diffraction element region, wherein the lens includes a first lens disposed closest to the first substrate, the first diffraction element region overlaps the first lens of the projector in an optical axis direction of the first lens, and a diameter of the first diffraction element region of the first substrate is smaller than a diameter of the first lens of the projector.