Abstract: A light projector has a light emitting device having a light emitting surface, an optical fiber having an incident end-face to which light emitted from the light emitting surface enters, and a lens arranged between the light emitting surface of the light emitting device and the incident end-face of the optical fiber. The light emitting device, the optical fiber and the lens are arranged on one optical axis. The optical fiber includes a core region as a region including a single core of uniform refractive index or a region collectively encompassing a plurality of cores having uniform refractive index. The lens converts diffused light emitted from the light emitting surface to diffused light that widens more moderately.

Abstract: A first light-blocking member and a second light-blocking member are adhered to each other by forming a light-transmitting layer having a light-transmitting composition serving as a base material and a light-transmitting filler different in index of refraction from this light-transmitting composition on a front surface of the first light-blocking member. A liquid light curing adhesive is applied to a front surface of the light-transmitting layer. The second light-blocking member is arranged on the front surface of the light-transmitting layer to which the liquid light curing adhesive has been applied. The liquid light curing adhesive is cured by irradiating the light-transmitting layer with light having a prescribed wavelength laterally from a side of the light-transmitting layer so as to adhere the light-transmitting layer and the second light-blocking member to each other.

Abstract: This invention provides a coaxial regressive reflection type photoelectronic sensor capable of enhancing detection accuracy. A sensor head includes a light emitting diode for emitting a detection light; a lens for converting the detection light to a parallel light and projecting the parallel light to an exterior as an external detection light; a half mirror for separating an optical path of the detection light and an optical path of a return light from the regressive reflection plate; and a photodiode for receiving the return light from the half mirror. The lens includes a convex surface formed to convert a signal light to a parallel light, and a plane tilted from a perpendicular direction with respect to the parallel light or an axis connecting a light emitting diode chip and a center portion of the convex surface. The reflected light of an external signal light at the plane passes a path different from that of the return light so as to be avoided from entering the photodiode chip.

Abstract: A recursive-reflective photoelectric sensor has a sensor main body and a recursive reflecting part. The sensor main body includes a light projecting part that projects first circularly polarized light and a light receiving part. When a mixture of the first circularly polarized light and second circularly polarized light which is differently polarized from the first circularly polarized light is incident to the light receiving part, only the second circularly polarized light is selectively passed. The recursive reflecting part reflects the first circularly polarized light by converting into reflected light that includes the second circularly polarized light.

Abstract: A recursive-reflective photoelectric sensor has a sensor main body and a recursive reflecting part. The sensor main body includes a light projecting part that projects first circularly polarized light and a light receiving part. When a mixture of the first circularly polarized light and second circularly polarized light which is differently polarized from the first circularly polarized light is incident to the light receiving part, only the second circularly polarized light is selectively passed. The recursive reflecting part reflects the first circularly polarized light by converting into reflected light that includes the second circularly polarized light.

Abstract: An optical module is formed with a semiconductor optical element sealed inside a transparent resin part and a lens unit affixed to its upper surface. The-lens unit has a lens part that is disposed facing opposite the semiconductor optical element through the transparent resin part. A planar part extends from the lens part along the upper surface of the transparent resin part. A photoelectric sensor may include such an optical module as a light projector and another such optical module as a light receiver.