Electro-optical instrument with self-contained photometer

An optical instrument for measuring characteristics of a surface of a specimen comprising, a source of light, said instrument directing a beam of light from the source obliquely at a selected angle .beta. to an optical axis positioned normal to the surface of the specimen, said specimen reflecting the light beam from the surface to provide a reflected beam having the same angle .beta. to the optical axis, a first reflective means for deflecting the reflected beam centrally toward the optical axis, a second reflective means for deflecting the centrally directed beam along said optical axis toward the specimen, photosensor means positioned to receive light from the beam after being reflected from the specimen to measure characteristics of the specimen, the beam from the second reflective means being positioned normal to the surface of the specimen to define the location of said optical axis of the instrument, the oblique beam directed from the source toward the specimen intersecting said optical axis and intersecting said surface of the specimen at a selected point when the instrument is at a selected standoff distance from the instrument, but when the specimen is moved toward or away from the instrument on said optical axis in either direction or is tilted, the beam reflected from the specimen is displaced thereby, and a photosensor positioned to detect the displaced beam when the surface of the specimen is moved to a position other than the standoff distance from the instrument or tilted with respect to a line normal to the surface of the specimen.

An optical instrument to be used for projecting a beam of light onto a specimen and for evaluating the specimen, said instrument comprising,

• a source of light,
• said instrument directing a beam of light from the source of light obliquely onto the specimen, said specimen reflecting the light beam from the surface thereof to provide an oblique reflected beam, said instrument having an optical axis normal to the specimen,
• means for deflecting said reflected beam toward the specimen along the optical axis,
• photosensor means positioned to intercept one of said beams and being located to receive said beam of light reflected from said specimen for detecting a characteristic of the light received from the specimen, and
• the photosensor means has means permitting two-way transmission of light past itself proceeding both toward and away from said photosensor in opposite directions when the light source is energized.

The optical instrument for measuring characteristics of a surface of a specimen comprising,

• a light source for illuminating a specimen adapted to reflect at least some of the light incident thereto,
• said instrument including means for directing an outbound beam of light proceeding from the source to the specimen and striking the specimen at a predetermined oblique angle incident thereto, said outbound beam being reflected from the specimen to provide an oblique reflected outbound beam proceeding away from the specimen at the same angle of reflection as the oblique beam incident to the specimen,
• means for directing the reflected outbound beam back toward the specimen so as to strike the specimen along an optical axis normal to the surface of the specimen and the beam normal thereto then being reflected from the specimen as a returning beam that travels back toward the light source in the opposite direction from the outbound beam, and
• a photosensor means interposed in the path of the outbound and returning beams for sensing a characteristic of light incident thereto.