The present invention, seated portion is formed, that the support base is formed at both sides of the seat portion; Electronic board which is mounted on the receiving portions of the base, the light emitting element, light receiving element, the compensation element is installed; It should accept or receive for receiving the light-receiving element and a compensating element for the light-emitting element; And including therein that the acceptance and the electronic board window lens is coupled to the base; comprising the said light emitting elements are evenly or unevenly arranged on the electronic board according to the light quantity of the light emitting element to be made incident on the light-receiving element , the receiving box is, to accommodate the light-emitting element, receiving the light-emitting device having a light-emitting lens on the image side of the light emitting element also; and the accommodating the light-receiving element and the compensating element, a light-receiving lens is provided on the upper side of the light-receiving element, and in that it comprises the technical features; also receiving the light receiving element is a reflector formed on an upper side of the compensating element.
In addition, the present invention is to be installed so that the upright to the compensation device to the electronic substrate, and the reflector is formed to have a compensation element provided upright with a predetermined angle to the technical features.