| US 7,492,446 B2 | ||
| Active beam catcher | ||
| Reinhard Waibel, Berneck (Switzerland) | ||
| Assigned to Hilti Aktiengesellschaft, Schaan (Liechtenstein) | ||
| Filed on Dec. 07, 2005, as Appl. No. 11/297,102. | ||
| Claims priority of application No. 10 2004 059 639 (DE), filed on Dec. 10, 2004. | ||
| Prior Publication US 2006/0126078 A1, Jun. 15, 2006 | ||
| Int. Cl. G01J 1/00 (2006.01) | ||
| U.S. Cl. 356—121 [250/214 R] | 9 Claims |
| 1. A beam catcher for a light beam (1), comprising:
a photodetector (6) having a plurality of photodiodes (8) which are offset along a line in a defined manner with respect to a reference point (7);
an evaluating unit (11) having a parameter set (P) of at least one associated line laser transmitter (2) for emitting the light beam (1);
a quantity determining module (13) for determining an energy quantity associated with a detected light energy (L) of the light beam (1);
an error estimating module (14) for determining an error estimation value (F) from a line energy density (ρ) and the parameter set (P), using an estimating
function (f);
a decision module (15) for comparing the error estimation value (F) to a threshold error value (G), and for generating and outputting an error
signal (Θ) to a user when the error estimation value (F) exceeds the threshold error value (G), to stop the user from positioning
the beam catcher with an excess total error in position; and
an offset display (9) for displaying offset of the light beam (1) with respect to the reference point (7).
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