Optical device, image reading device, and imaging forming apparatus
An optical device includes: a lens body having multiple lenses arranged such that optical axes thereof are parallel to one another; a light-shielding wall that is disposed for the lens body and blocks, in an optical axis direction, portion of light directed to the multiple lenses; and a sheet member that covers a surface of the light-shielding wall, the surface being perpendicular to the optical axes, and allows light to pass therethrough.
1. An optical device comprising:
a lens body having a plurality of lenses arranged such that optical axes thereof are parallel to one another;
a light-shielding wall that is disposed for the lens body and blocks, in an optical axis direction, a portion of light directed to the plurality of lenses; and
a sheet member that covers a surface of the light-shielding wall, the surface being perpendicular to the optical axes, and allows light to pass therethrough,
wherein the light-shielding wall is thicker than the sheet member.
2. The optical device according to claim 1 , wherein the sheet member is divided into multiple pieces in a longitudinal direction of the light-shielding wall intersecting the optical axis direction and is bonded to the light-shielding wall.
3. The optical device according to claim 2 , wherein the sheet member is a transparent glass plate having a thickness of less than 0.1 mm.
4. The optical device according to claim 2 , wherein
the light-shielding wall is divided into multiple pieces in the longitudinal direction, and the pieces are joined together at a division surface and disposed on the lens body, and
the sheet member is bonded to one surface of each piece of the light-shielding wall.
5. The optical device according to claim 4 , wherein the sheet member is a transparent resin film having a thickness of less than 0.5 mm.
6. The optical device according to claim 4 , wherein the sheet member is a transparent glass plate having a thickness of less than 0.1 mm.
7. The optical device according to claim 2 , wherein
the light-shielding wall is divided into multiple pieces in the longitudinal direction, and the pieces are joined together at a division surface and disposed on the lens body, and
the sheet member is bonded to the light-shielding wall so as to straddle the division surface.
8. The optical device according to claim 7 , wherein the sheet member is a transparent resin film having a thickness of less than 0.5 mm.
9. The optical device according to claim 7 , wherein the sheet member is a transparent glass plate having a thickness of less than 0.1 mm.
10. The optical device according to claim 2 , wherein the sheet member is a transparent resin film having a thickness of less than 0.5 mm.
11. The optical device according to claim 1 , wherein the sheet member and the light-shielding wall are configured as a single component.
12. The optical device according to claim 11 , wherein the sheet member is a transparent resin film having a thickness of less than 0.5 mm.
13. The optical device according to claim 1 , wherein the sheet member is bonded to each of opposing surfaces of the light-shielding wall so as to sandwich the light shielding wall.
14. The optical device according to claim 13 , wherein the sheet member is a transparent resin film having a thickness of less than 0.5 mm.
15. The optical device according to claim 1 , wherein the sheet member extends over an entire light-shielding wall in the longitudinal direction intersecting the optical axis direction and is bonded to the surface.
16. The optical device according to claim 15 , wherein the sheet member is a transparent resin film having a thickness of less than 0.5 mm.
17. The optical device according to claim 1 , wherein the sheet member is a transparent resin film having a thickness of less than 0.5 mm.
18. The optical device according to claim 1 , wherein the sheet member is a transparent glass plate having a thickness of less than 0.1 mm.
19. An image reading device comprising:
an illuminating part that radiates light onto an original document;
the optical device according to claim 1 ;
a light-receiving part that receives light passing through the optical device; and
a moving part that integrally moves the illuminating part, the optical device, and the light-receiving part in a direction perpendicular to the optical axis direction and the longitudinal direction.
20. An image forming apparatus comprising:
the image reading device according to claim 19 , which reads an image on an original document; and
an image recording part that records the image read by the image reading device on a recording medium.