Optical reading apparatus for reading latent image mark

An optical reading apparatus for reading a latent image mark, comprising:

• a light-projecting member for projecting on a surface of the latent image mark light having a wavelength to excite a fluorescent substance contained in the latent image mark having desired information;
• a light-receiving member for receiving fluorescence emitted from the surface of the latent image mark;
• a mirror for reflecting the fluorescence emitted from the surface of the latent image mark onto the light-receiving member;
• an image forming lens group for transmitting the fluorescence emitted from the surface of the latent image mark onto the light-receiving member;
• an upper frame and a lower frame having said light-receiving member, said image forming lens group, and said mirror located therein such that said light-receiving member, said image forming lens group, and said mirror are spaced from each other by a fixed interval;
• and
• an enclosure enclosing each of said light-protecting member, said upper frame and said lower frame,
• wherein a range in which the latent image mark can be read is formed by setting a point at which an optical axis of the light-projecting member and that of the light-receiving member intersect with each other as a reference;
• and an intersection angle between the two optical axes is in the range of from 10.degree. to 40.degree..