Abstract: A light projecting device comprises a flat light guide plate and a light source that introduces light into the light guide plate from a side peripheral surface thereof. A plurality of concave parts are formed on one plate surface of the light guide plate, and the light entering the light guide plate reflects off the concave parts while spreading out, and the light is emitted outside from the other plate surface of the light guide plate. Each concave part is formed by a smooth concave curved surface. A tangential angle that is an angle between a tangential line at an opening edge of the concave part and the plate surface is set to be ?50° and ?85° in a cross-sectional shape of the concave part cut by a plane that is both perpendicular to the plate surface and passing through the center of the concave part.

Abstract: A light projecting device comprises a flat plate shaped light guide plate and a light source that introduces light into the light guide plate from a side peripheral surface thereof. A plurality of concave parts are formed on one plate surface of the light guide plate, and the light entering the light guide plate reflects off the concave parts while spreading out, and the light is emitted outside from the other plate surface of the light guide plate. Each concave part is formed by a smooth concave curved surface. A tangential angle that is an angle between a tangential line at an opening edge of the concave part and the plate surface is set to be ?50° and ?85° in a cross-sectional shape of the concave part cut by a plane that is both perpendicular to the plate surface and passing through the center of the concave part.

Abstract: An imaging device includes a light source, a plurality of lenses disposed adjacent to one another on a predetermined plane, a diffuser plate that diffuses light to be emitted from the light source, and an imaging element that includes a plurality of pixels, the imaging element being configured to receive reflection light generated by causing the light diffused by the diffuser plate to be reflected from a subject. The plurality of lenses are disposed so that a period of interference fringes in the diffused light is less than or equal to three pixels of the imaging element. This configuration can provide the imaging device in which an influence of the interference fringes of the diffused light can be suppressed in an image that is obtained when an image of the subject is captured by irradiating the subject with the light diffused by the diffuser plate having the plurality of lenses.

Abstract: An imaging device includes a light source, a plurality of lenses disposed adjacent to one another on a predetermined plane, diffuser plate that diffuses light to be emitted from the light source, and an imaging element that includes a plurality of pixels, the imaging element being configured to receive reflection light generated by causing the light diffused by the diffuser plate to be reflected from a subject. The plurality of lenses are disposed so that a period of interference fringes in the diffused light is less than or equal to three pixels of the imaging element. This configuration can provide the imaging device in which an influence of the interference fringes of the diffused light can be suppressed in an image that is obtained when an image of the subject is captured by irradiating the subject with the light diffused by the diffuser plate having the plurality of lenses.

Abstract: A lens barrel includes: a lens holder; and an imaging lens that includes a plurality of lenses inserted in the lens holder, the plurality being at least three, wherein a resin spacer having elasticity in an optical axis direction is disposed between the lenses that affect field curvature, and the resin spacer is deformed and fixed in position by compressing a space between the lenses that affect the field curvature. Accordingly, the space between the lenses that tend to affect the field curvature is compressed to elastically deform the resin spacer in an optical axis direction, to thereby make it possible to adjust an interval between the lenses. Consequently, it is possible to correct the field curvature, to thereby prevent lowering of resolution.