Device for optoelectronic monitoring of objects and detecting of light beams scattered at a faceplate

• US 7,622,728 B2
• Filed: 01/23/2007
• Issued: 11/24/2009
• Est. Priority Date: 01/27/2006
• Status: Expired due to Fees

• Current Assignee: Sick AG (Sick)
• Original Assignee: Sick AG (Sick)
• Inventors: Wuestefeld, Martin
• Primary Examiner(s): Luu; Thanh X
• Assistant Examiner(s): Legasse, Jr.; Francis M
• Application Number:
  US11/656,498
• Publication Number:
  US 20070215822A1
• Time in Patent Office: 1,036 Days
• Field of Search: 250/221, 250/222.1, 250/224, 250/559.4, 356/237.2, 356/237.3, 356/239.7, 356/239.8, 340555-557
• US Class Current: 250/559.4
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 2007/4975 of sensor obstruction by, e.g. dirt- or ice-coating, e.g. by reflection measurement on front-screen
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating

Abstract

A device for optoelectronic monitoring of an object (26) contains a transmitting unit (12) and a receiving unit (14) that are located in a housing (10) covered by a faceplate (16). The transmitting unit (12) emits light beams (24) in a structured illuminating pattern. The illuminating pattern of the illuminated object (26) is recorded on an image recorder (28) by the receiving unit (14). Soiling (38) on the faceplate (16) is indicated by recording the light beams (24) diffusely scattered at the faceplate (16) on the image recorder (28).

Claims

1. Device for optoelectronic monitoring of objects, with a transmitting unit (12) that transmits light beams (24) in a structured illuminating pattern, with a receiving unit (14), that contains an image recorder (28) on which the object (26) illuminated with structured illuminating pattern is recorded, and with a housing (10) in which the transmitting unit (12) and the receiving unit (14) are located and which has a faceplate (16) for the transmitting unit (12) and the receiving unit (14), characterized in that the transmitting unit (12), the receiving unit (14), and the faceplate (16) are positioned in the housing (10) so that the light beams that are directly reflected at the faceplate (16) do not travel into the image recorder (28) of the receiving unit (14) and so that beams from the transmitting unit (14) separately from the recording of the object (26) by means of receiving optics (30) included in the receiving unit (14),

characterized in that the image recorder (28) contains a matrix arrangement of photoelectric elements and that light beams (24) diffusely scattered at the faceplate (16) are recorded by the image recorder (28) separate from recording of the object (26).

2. Device according to claim 1, characterized in that the transmitting unit (12) contains a light source (18), a beam collimator (20), and a diffractive optical element (22) for purposes of producing the light beams (24).

3. Device according to claim 1, characterized in that the light beams (24) are individual beams spread fan-like in a scanning plane and in that the receiving unit (14) observes the object (26) at a viewing angle that is inclined with respect to this scanning plane.

4. Device according to claim 1, characterized in that the faceplate (16) has a diffusely scattering zone (46) whose recording (48) on the image recorder (28) is used for monitoring functionality.

5. Device according to claim 1, characterized in that the receiving unit contains an additional receiving element (52) that is separate from the image recorder (28).

6. Device according to claim 1, characterized in that a wide angle light source (50) is provided that completely illuminates the image recorder (28) for purposes of checking functionality.

7. Device according to claim 5, characterized in that the receiving element receives beams from the transmitting unit (12) that are diffusely scattered at the faceplate (16).

8. Device according to claim 7, characterized in that the receiving element (52) receives beams from the transmitting unit (12) that are directly reflected at the faceplate (16).