Patent ID: 8395107

Claim:
A main body unit of an optical fiber photoelectric sensor, comprising: an attaching portion which attaches a light projecting side optical fiber that guides light to be projected toward a detection area and a light receiving side optical fiber that receives light from the detection area and guides the light; a light projecting unit which projects light to the light projecting side optical fiber attached to the attaching portion; and a light receiving unit which receives the light incident on the light receiving side optical fiber, the main body unit detecting an object to be detected in the detection area based on an amount of light received by the light receiving unit, the light projecting unit including: a light emitting element which emits light; a condenser lens which is provided between the light emitting element and the attaching portion so as to make the light emitted from the light emitting element converge to one end surface of the light projecting side optical fiber attached to the attaching portion; a reflecting surface which is provided around the condenser lens in a substantially concentric circle shape with respect to an optical axis of the condenser lens, and makes light emitted from the light emitting element to around the condenser lens reflect in a direction coming close to the optical axis of the condenser lens wherein the reflecting surface is perpendicular to the upper surface of the light projecting unit; and a refractive surface which is provided between the condenser lens and the reflecting surface in a substantially concentric circle shape with respect to the optical axis of the condenser lens, and makes the light reflected by the reflecting surface refract from the direction coming close to the optical axis of the condenser lens to a direction along the optical axis and incident on one end surface of the light projecting side optical fiber attached to the attaching portion, and wherein the light projecting unit includes: a light emitting diode chip serving as the light emitting element; and a translucent resin layer which seals the light emitting diode chip, and wherein the condenser lens, the reflecting surface, and the refractive surface are integrally formed by forming the translucent resin layer; and wherein the translucent resin layer is provided with a groove portion or a cutout portion having a concentric circle shape with respect to the optical axis of the condenser lens, the groove portion or the cutout portion being provided on a surface of the translucent resin layer facing one end surface of the light projecting side optical fiber, and the reflecting surface is formed by the cutout portion or an inner circumferential surface of the groove portion.