Method of manufacturing lens array plate, erecting equal-magnification lens array plate, and optical scanning unit, and image reading device

An optical scanning unit comprising:

• a linear light source configured to illuminate a document to be read;
• an erecting equal-magnification lens array plate configured to condense light reflected by the document to be read, comprising:
• a light shielding film formed on a flat surface of a substrate;
• a plurality of lenses of the substrate formed by press molding the flat surface of the substrate with the light shielding film, the press molding comprising forming the lenses by pressing a lens formation area, the plurality of lenses being recessed in the substrate;
• wherein the light shielding film is not formed in a lens formation area in which a lens is formed,
• wherein the forming of lenses comprises:
• press molding an area formed around the lens formation area and formed with the light shielding film, thereby forming a recess having a substantially columnar profile that extends from the surface of the substrate toward the interior thereof, the substantially columnar profile being comprised of an interior sidewall surface and a bottom interior surface, wherein the sidewall surface of the recess is provided with the light shielding film bent and extended by the press molding;
• and
• forming the lens on the bottom interior surface of the recess by press molding the lens formation area of the substrate,
• wherein a stack of a plurality of lens array plates is formed;
• and
• a linear image sensor configured to receive light transmitted by the erecting equal-magnification lens array plate.

A method of manufacturing a lens array plate comprising:

• preparing a dielectric substrate having parallel flat surfaces;
• forming, subsequent to the preparing the dielectric substrate, a light shielding film on a flat surface of the substrate;
• and
• forming, subsequent to the forming the light shielding film, a lens in the substrate by press molding the flat surface of substrate,
• wherein the light shielding film is not formed in a lens formation area in which a lens is formed,
• wherein the forming of the lens comprises:
• press molding an area formed around the lens formation area and formed with the light shielding film, thereby forming a recess having a substantially columnar profile that extends from the surface of the substrate toward the interior thereof, the substantially columnar profile being comprised of an interior sidewall surface and a bottom interior surface, wherein the sidewall surface of the recess is provided with the light shielding film bent and extended by the press molding;
• and
• forming the lens on the bottom interior surface of the recess by press molding the lens formation area of the substrate, and
• wherein portions of a press mold for forming the lens and the recess are formed on the same surface.