Detector for determining a position of at least one object

Patent metadata

Field	Value
Publication number	US-11940263-B2
Application number	US-201917269443-A
Country	US
Kind code	B2
Filing date	Aug 23, 2019
Priority date	Aug 24, 2018
Publication date	Mar 26, 2024
Grant date	Mar 26, 2024

Abstract

Described herein is a detector for determining a position of at least one object. The detector includes:at least one transfer device;at least one illumination source adapted to generate at least one light beam for illuminating the object;at least one first optical receiving fiber and at least one second optical receiving fiber;at least two optical sensors; andat least one evaluation device being configured for determining at least one longitudinal coordinate z of the object by evaluating a combined signal Q from the sensor signals.

First claim

The invention claimed is:

1. A detector ( 112 ) for determining a position of at least one object ( 114 ), the detector ( 112 ) comprising:
at least one transfer device ( 130 ), wherein the transfer device ( 130 ) has at least one focal length in response to the at least one incident light beam propagating from the object ( 114 ) to the detector ( 112 ), wherein the transfer device ( 130 ) has at least one optical axis ( 142 );
at least one illumination source ( 144 ) adapted to generate at least one light beam ( 146 ) for illuminating the object ( 114 ), wherein an exit pupil of the illumination source ( 144 ) is displaced from the optical axis ( 142 ) by a distance BL, wherein the illumination source ( 144 ) has a geometrical extend G in a range 3·10 −4 mm 2 ·sr≤G≤3.3 mm 2 ·sr; wherein the illumination source ( 144 ) comprises at least one optical sender fiber ( 118 ) for illuminating the object ( 114 );
at least one first optical receiving fiber ( 120 , 126 ) and at least one second optical receiving fiber ( 120 , 124 ), wherein each of the optical receiving fibers ( 120 , 126 , 128 ) comprises at least one cladding ( 136 ) and at least one core ( 134 ), wherein the first optical receiving fiber ( 120 , 122 ) has a core diameter of d 1 , wherein the second optical receiving fiber ( 120 , 124 ) has a core diameter of d 2 , wherein the ratio d 1 /BL is in a range 0.000318≤d 1 /BL≤6.83, and/or wherein the ratio d 2 /BL is in a range 0.000318≤d 2 /BL≤6.83; wherein an entrance face of at least one of the optical receiving fibers ( 120 , 126 , 124 ) is arranged such that a variance over distance dependence of the combined signal is maximal, wherein the entrance face of at least one of the optical receiving fibers ( 120 , 126 , 124 ) is positioned as such that a combined signal Q far at large object distances and a combined signal Q close at small object distances have a maximum variation

Q
far

Q

c
⁢
l
⁢
o
⁢
s
⁢
e

≈

r
Coc

Object
,
close

(

z
O

,

Z
s

,

Z
i

)

2

r
Coc

Object
,
far

(

z
O

,

Z
s

,

Z
i

)

2

→
max

,

wherein r Coc Object,close is a radius of the circle of confusion at small object distances and r Coc Object,far is a radius of the circle of confusion at large object distances, wherein z O is a detectable distance range between the entrance face of at least one of the optical receiving fibers ( 120 , 126 , 124 ) and the object, z s is a distance between the transfer device ( 130 ) and the entrance face of at least one of the optical receiving fibers ( 120 , 126 , 124 ) and z i is a position of the focused image behind the transfer device ( 130 ), which depends on the position of the object z o ;
at least two optical sensors ( 126 , 128 ), wherein at least one first optical sensor ( 126 ) is arranged at an exit end of the first optical receiving fiber ( 120 , 122 ) and at least one second optical sensor ( 128 ) is arranged at an exit end of the second optical receiving fiber ( 120 , 124 ), wherein each optical sensor ( 126 , 128 ) has at least one light sensitive area ( 147 ), wherein each optical sensor ( 126 , 128 ) is designed to generate at least one sensor signal in response to an illumination of its respective light-sensitive area ( 148 ) by a light beam having passed through the respective optical receiving fiber ( 120 , 122 , 124 ); and
at least one evaluation device ( 150 ) being configured for determining at least one longitudinal coordinate z of the object ( 114 ) by evaluating a combined signal Q from the sensor signals.

2. The detector ( 112 ) according to claim 1 , wherein the illumination source ( 144 ) is configured to illuminate the object ( 114 ) under an angle α illu with respect to the optical axis ( 142 ), wherein the angle is in a range 0°≤α illu ≤40.

3. The detector ( 112 ) according to claim 1 , wherein at least one of the optical receiving fibers ( 120 , 122 , 124 ) and/or the transfer device ( 130 ) has a ratio ε r /k in a range 0.362 (m·K)/W≤ε r /k≤1854 (m·K)/W, wherein k is the thermal conductivity and ε r is the relative permittivity.

4. The detector ( 112 ) according to claim 1 , wherein the transfer device ( 130 ) has a ratio v e /n D in a range 9.05≤v e /n D ≤77.3, wherein v e is the Abbé-number and n D is the refractive index, wherein the Abbé-number v e is given by

v
e

=

(

n
D

-
1

)

(

n
F

-

n
c

)

,

wherein n i is the refractive index for different wavelengths, wherein n C is the refractive index for 656 nm, n D is the r

Assignees

• Trinamix Gmbh

Inventors

• Oeguen Celal Mohan
• Eberspach Michael
• Send Robert
• Bruder Ingmar

Classifications

• G01B11/002 Primary

  for measuring two or more coordinates · CPC title

• G02B6/02

  Optical fibres with cladding {with or without a coating} · CPC title

• G02B6/262

  Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements · CPC title

• G01B11/24 Primary

  for measuring contours or curvatures · CPC title

• G01B11/026 Primary

  by measuring distance between sensor and object (G01B11/0608 takes precedence) · CPC title