Patent ID: 11874484
Assignee: DEXERIALS CORPORATION
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 8:
9. A method of manufacturing a polarizing plate having a wire grid structure and an absorption axis reflectance that is minimized in a wavelength of light in a band to be used, the method comprising:
forming a reflective layer over a transparent substrate;
forming a first dielectric layer on the reflective layer;
forming an absorptive layer on the first dielectric layer;
forming a second dielectric layer on the absorptive layer;
etching a resultant laminate in a selective manner to form, over the transparent substrate, grid protrusions arranged in an array having a pitch shorter than the wavelength of light in the band to be used, and extending in a predetermined direction; and
coating, with a protective film made of a dielectric material, a surface of the transparent substrate having the grid protrusions formed thereover, the surface of the transparent substrate constituting a surface of the polarizing plate, the surface of the polarizing plate being configured to receive incident light,
the etching including making a width of the reflective layer in the grid protrusions smaller than a width of the first dielectric layer in the grid protrusions, a width of the second dielectric layer in the grid protrusions, and a width of the absorptive layer in the grid protrusions; and
adjusting the width of the reflective layer in the grid protrusions such that the absorption axis reflectance of the polarizing plate is minimized in the wavelength of light in the band to be used,
wherein the width of the first dielectric layer, the width of the second dielectric layer, and the width of the absorptive layer are substantially equal to one another,
wherein the first dielectric layer, the second dielectric layer, and the absorptive layer each have a thickness such that, in response to the width of the reflective layer in the grid protrusions being equal to the width of the first dielectric layer in the grid protrusions, the width of the second dielectric layer in the grid protrusions, and the width of the absorptive layer in the grid protrusions, the absorption axis reflectance of the polarizing plate is minimized in a wavelength shorter than the wavelength of light in the band to be used, and
wherein a surface of the second dielectric layer is in contact with the protective film.