Abstract: An embodiment of the present invention discloses a camera actuator comprising: a housing; a mover on which an optical member sits and which is disposed inside the housing; a ball part including a first ball and a second ball and disposed between the housing and the mover; and a driving unit that is disposed inside the housing to drive the mover, wherein the mover includes a first protrusion extending toward the housing and including a recess. The recess includes: a side surface on which the ball part sits and on which at least a portion of the recess is spaced apart from the ball part; and a bottom surface in contact with the side surface.

Abstract: An optical system disclosed in an embodiment of the invention includes an optical path changing member and a plurality of lenses sequentially disposed along an optical axis from an object side to an image side, the light path changing member includes a reflective mirror or a prism, a distance between the plurality of lenses does not change, and a lens closest to an image side of the plurality of lenses has a larger effective aperture than the other lenses.

Abstract: A method of fabricating a polarizing plate includes: providing a polarizing roll film having transmission axes; and cutting the polarizing roll film with a knife having a plurality of openings each having a rectangular shape to form a plurality of polarizing plates, the plurality of openings parallel to the transmission axes.

Abstract: A polarization direction measuring apparatus includes: a first polarizing plate having an unknown polarization direction about a reference axis; a sample whose polarization direction is to be measured; a rotatable sample holder on which the sample is mounted in a first direction and a second direction opposite to the first direction, wherein the sample holder rotates the sample along a reference axis in the azimuth direction; a light source that generates light passing though the first polarizing plate and the sample; and a light detector detecting light generated by the light source that passes though the first polarizing plate and the sample.

Abstract: A method of fabricating a polarizing plate includes: providing a polarizing roll film having transmission axes; and cutting the polarizing roll film with a knife having a plurality of openings each having a rectangular shape to form a plurality of polarizing plates, the plurality of openings parallel to the transmission axes.