×

Method and apparatus for determining the distance between a base and a specular surface by means of radiation reflected at the surface

  • US 5,933,240 A
  • Filed: 02/12/1997
  • Issued: 08/03/1999
  • Est. Priority Date: 02/12/1997
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method for determining the distance (h) between a base (1) and the specular surface (2) of an object (3), which comprises the steps of:

  • (a) initially divergently irradiating the specular surface solely with light energy radiated from a first light source (4) arranged adjacent the base and transmitted via a first semi-transparent mirror (9);

    (b) measuring the intensity of the first light energy reflected by the specular surface as a first virtual image of the first light source and transmitted via a second semi-transparent mirror (8) upon a first detector (5) arranged at a first angle of appearance (γ

    ) relative to the base, thereby to produce at least one first electrical signal (A1, A2);

    (c) subsequently divergently irradiating the specular surface solely radiated from a second light source (6) arranged adjacent said first detector and reflected by said second mirror;

    (d) measuring the intensity of the second light energy that is reflected by said specular surface and by said first mirror as a second virtual image upon a second detector (7) arranged adjacent said first light source at a second angle of appearance (α

    ) relative to the base, thereby to produce at least one second electrical signal (B1,B2);

    (e) alternatively time-division multiplexing (14) the first and second signals to determine the angles of appearance (α

    , γ

    ) of the first and second virtual images relative to the base, and the distance (d) between the apices of the angles of appearance relative to the base; and

    (f) calculating the distance (h) between the base and the specular surface of the object.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×