US-12619013-B2 - Optical device and image reading device with a plurality of lenses and light-blocking body

Abstract

An optical device includes: a lens body including plural lenses arranged such that optical axes of the plural lenses extend along each other; and a light-blocking body disposed on a light incident side of the lens body and including light-transmitting portions that transmit light and light-blocking portions that block light, the light-transmitting portions and the light-blocking portions being continuously arranged in an alternating manner such that the light-transmitting portions are positioned at the plural lenses and that the light-blocking portions are positioned between the plural lenses.

Inventors

• Masaki Hachisuga

Assignees

• FUJIFILM BUSINESS INNOVATION CORP.

Dates

Publication Date

20260505

Application Date

20230117

Priority Date

20220909

Claims (6)

1. 1 . An optical device comprising: a lens body including a plurality of lenses arranged such that optical axes of the plurality of lenses extend along each other; and a light-blocking body disposed on a light incident side of the lens body and including light-transmitting portions that transmit light and light-blocking portions that block light, the light-transmitting portions and the light-blocking portions being continuously arranged in an alternating manner such that the light-transmitting portions are positioned at the plurality of lenses and that the light-blocking portions are positioned between the plurality of lenses, wherein the light-blocking body has: a light-blocking direction that is a direction in which the light-transmitting portions and the light-blocking portions are continuously arranged in the alternating manner and in which the light-blocking portions block light from entering the plurality of lenses; and a light-unblocking direction that is a direction that crosses the light-blocking direction and in which the light-blocking portions do not block light.
2. 2 . The optical device according to claim 1 , wherein a position of the light-unblocking direction in the light-blocking direction is constant between one side and other side in the light-unblocking direction.
3. 3 . The optical device according to claim 1 , wherein a position of the light-unblocking direction in the light-blocking direction differs between one side and other side in the light-unblocking direction.
4. 4 . The optical device according to claim 1 , wherein the light-blocking portions of the light-blocking body include extending surfaces that extend in a direction crossing a direction in which the light-transmitting portions and the light-blocking portions are continuously arranged in the alternating manner.
5. 5 . The optical device according to claim 4 , wherein the extending surfaces include: first surfaces positioned at the plurality of lenses of the lens body; and second surfaces that are at an angle with respect to the first surfaces.
6. 6 . An image reading device comprising: an irradiation unit that irradiates a document with light; a lens body including a plurality of lenses arranged such that optical axes of the plurality of lenses extend along each other, the plurality of lenses transmitting light reflected by the document; a light-blocking body disposed on a light incident side of the lens body and including light-transmitting portions that transmit light and light-blocking portions that block light, the light-transmitting portions and the light-blocking portions being continuously arranged in an alternating manner such that the light-transmitting portions are positioned at the plurality of lenses and that the light-blocking portions are positioned between the plurality of lenses, wherein the light-blocking body has: a light-blocking direction that is a direction in which the light-transmitting portions and the light-blocking portions are continuously arranged in the alternating manner and in which the light-blocking portions block light from entering the plurality of lenses; and a light-unblocking direction that is a direction that crosses the light-blocking direction and in which the light-blocking portions do not block light; and a light-receiving unit that receives light from the plurality of lenses.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2022-143480 filed Sep. 9, 2022. BACKGROUND (i) Technical Field The present disclosure relates to an optical device and an image reading device. (ii) Related Art Japanese Unexamined Patent Application Publication No. 2003-302504, for example, describes an optical device including a lens array unit including at least one lens array and a first light-blocking mask, the lens array including plural lenses that are arranged in rows and having plural first lens surfaces through which light is incident and plural second lens surfaces through which light is emitted, the first light-blocking mask having plural through holes that extend therethrough in an axial length direction of each lens and covering a front surface of the lens array such that the through holes are positioned in front of respective ones of the first lens surfaces. The lens array unit also includes a second light-blocking mask having plural through holes that extend therethrough in the axial length direction of each lens and being disposed behind the lens array such that the through holes are positioned behind respective ones of the second lens surfaces. SUMMARY The lens performance of a lens body including plural lenses arranged such that optical axes thereof extend along each other may be improved by reducing intervals between the lenses. However, in such a case, the occurrence of molding failure in a resin molding process increases due to reduction in the thickness of a light-blocking body, and the manufacturing cost cannot be easily reduced. Aspects of non-limiting embodiments of the present disclosure relate to reduction of influence on lens performance compared to that in a device including a lens body and a light-blocking body formed by resin molding. Aspects of certain non-limiting embodiments of the present disclosure overcome the above disadvantages and/or other disadvantages not described above. However, aspects of the non-limiting embodiments are not required to overcome the disadvantages described above, and aspects of the non-limiting embodiments of the present disclosure may not overcome any of the disadvantages described above. According to an aspect of the present disclosure, there is provided an optical device including: a lens body including plural lenses arranged such that optical axes of the plural lenses extend along each other; and a light-blocking body disposed on a light incident side of the lens body and including light-transmitting portions that transmit light and light-blocking portions that block light, the light-transmitting portions and the light-blocking portions being continuously arranged in an alternating manner such that the light-transmitting portions are positioned at the plural lenses and that the light-blocking portions are positioned between the plural lenses. BRIEF DESCRIPTION OF THE DRAWINGS Exemplary embodiments of the present disclosure will be described in detail based on the following figures, wherein: FIG. 1 schematically illustrates an image forming apparatus to which an exemplary embodiment is applied; FIG. 2 schematically illustrates an image reading device to which the exemplary embodiment is applied; FIG. 3 illustrates a manner in which light reflected by a document placed on a transparent plate is received by light-receiving elements on a light-receiving substrate; FIGS. 4A to 4E illustrate sequential steps for manufacturing a light-blocking wall according to a first exemplary embodiment; FIG. 5 illustrates the relative positional relationship between the light-blocking wall and a microlens array according to the first exemplary embodiment; FIGS. 6A to 6E illustrate sequential steps for manufacturing a light-blocking wall according to a second exemplary embodiment; FIG. 7 illustrates the relative positional relationship between the light-blocking wall and a microlens array according to the second exemplary embodiment; FIG. 8 illustrates blockage of light for the microlens array having a two-row arrangement according to the second exemplary embodiment; FIGS. 9A and 9B illustrate other sequential steps for manufacturing the light-blocking wall according to the second exemplary embodiment; FIGS. 10A and 10B illustrate a light-blocking wall according to a third exemplary embodiment, wherein FIG. 10A illustrates the shape of a light-transmitting portion and light-blocking portions of the light-blocking wall and FIG. 10B illustrates the relative positional relationship between the light-blocking wall and a microlens array; and FIGS. 11A and 11B illustrate a light-blocking wall according to a fourth exemplary embodiment, wherein FIG. 11A illustrates the shape of a light-transmitting portion and light-blocking portions of the light-blocking wall and FIG. 11B illustrates the relative positional relationship between the light-blocking wall and a microlens array. DET