Laser scanning and sensing device for detection around automatic doors

• US 7,349,074 B2
• Filed: 07/21/2005
• Issued: 03/25/2008
• Est. Priority Date: 07/22/2004
• Status: Active Grant

• Current Assignee: BEA (Halma PLC)
• Original Assignee: BEA (Halma PLC)
• Inventors: Zambon, Alain
• Primary Examiner(s): Tarcza; Thomas H.
• Assistant Examiner(s): Ratcliffe; Luke D.
• Application Number:
  US11/186,555
• Publication Number:
  US 20060169876A1
• Time in Patent Office: 978 Days
• Field of Search: 356/5.01
• US Class Current: 356/5.01
• CPC Class Codes: E05F 15/43 responsive to disruption of energy beams, e.g. light or sound
• CPC Class Codes: E05F 15/608 for revolving wings
• CPC Class Codes: E05F 15/73 responsive to movement or presence of persons or objects
• CPC Class Codes: E05F 15/74 using photoelectric cells
• CPC Class Codes: E05Y 2900/132 Doors
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 17/18 wherein range gates are used
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/87 Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/88 Lidar systems specially adapted for specific applications
• CPC Class Codes: G01S 7/481 Constructional features, e.g. arrangements of optical elements
• CPC Class Codes: G01S 7/4813 Housing arrangements
• CPC Class Codes: G01S 7/4817 relating to scanning

Abstract

The present invention relates to a light scanner device (10) for measuring a range and an angular direction of a target object (56), the device (10) comprising a pulsed source (12) adapted to transmit light pulses, a transmitter deflection means (20) adapted to reflect and sweep the transmitted light pulses in variable sweep directions across a sweep sector in a sweep plane (15), a photodetection means (42) adapted to detect received light pulses that have been reflected in the sweep plane (15), a receiver deflection means (24) adapted to reflect light pulses that have been reflected in the sweep plane (15) and to re-direct the reflected light pulses to the photodetection means (42). The device comprises optical shielding means (32) adapted to optically shield transmitted light pulses on their trajectory from the pulse source (12) to the transmitter deflection means (20) and at least a portion of their trajectory extending from the transmitter deflection means (20) into the sweep sector from reflected light pulses on their trajectory between the photodetection means (42) and the receiver deflection means (24) and at least a portion of their trajectory extending in the sweep sector and ending on the receiver deflection means (24).

Claims

1. A light scanner device (10) for measuring a range and an angular direction of a target object (56), the device (10) comprising:

a pulse source (12) adapted to transmit light pulses,

a transmitter deflection means (20) adapted to sweep the transmitted light pulses in variable sweep directions across a sweep sector,

a photodetection means (42) adapted to detect received light pulses that have been reflected in the sweep sector,

a receiver deflection means (24) adapted to re-direct light pulses that have been reflected in the sweep plane (15) to the photodetection means (42), further comprising optical shielding means (32) adapted to optically shield transmitted light pulses on their trajectory from the pulse source (12) to the transmitter deflection means (20) and at least a portion of their trajectory extending from the transmitter deflection means (20) into the sweep sector from reflected light pulses on their trajectory between the photodetection means (42) and the receiver deflection means (24) and at least a portion of their trajectory extending in the sweep sector and ending on the receiver deflection means (24),

wherein the transmitter deflection means (20) and the receiver deflection means (24) both comprise a multi-facet mirror comprising a plurality of facets, with at least one pair of facets substantially parallel to each other, and wherein the multi-facet mirror of the transmitter deflection means (20) and the multi-facet mirror of the receiver deflection means (24) are adapted to be rotated in synchronism with each other on a common rotation axis (38),

wherein the multi-facet mirror of the transmitter deflection means (20) and the multi-facet mirror of the receiver deflection means (24) form a split multi-facet mirror comprising a groove adapted to optically separate the multi-facet mirror of the transmitter deflection means (20) and the multi-facet mirror of the receiver deflection means (24).

2. The device according to claim 1, further comprising a casing (18) adapted to accommodate at least the pulse source (12), the transmitter deflection means (20), the receiver deflection means (24), the photodetection means (42) and the optical shielding means (32), whereby the optical shielding means (32) shields transmitted pulses from received pulses on at least their whole trajectory portions located within the casing (18).

3. The device according to claim 1, wherein the optical shielding means (32) extends into said groove between the multi-facet mirror of the transmitter mirror facet means (20) and the multi-facet mirror of the receiver deflection means (24).

4. The device according to claim 1, wherein the receiver deflection means (24) comprises a stationary mirror adapted to receive light pulses reflected in the sweep plane (15).

5. The device according to claim 4, wherein the receiver deflection means (24) comprises a planar, spherical or cylindrical mirror portion.

6. The device according to claim 1, wherein the pulse source is a pulsed laser or a pulsed laser diode.

7. The device according to claim 1, wherein the photodetection means (42) comprises a high gain, high speed photodetector such as an avalanche photodiode.

8. The device according to claim 1, wherein the transmitter deflection means (20) and the receiver deflection means (24) include an axis of rotation and wherein said 4 facets are tilted enabling different sweep sectors according to different tilt angles of the 4 facets of the mirror.

9. The device according to claim 1, wherein the transmitter deflection means (20) and the receiver deflection means (24) include an axis of rotation and wherein said 4 facets each include a tilt angle and wherein the sweep sector is variable between subsequent sweeps by an incremental tilt angle.

10. The device according to claim 1 having a detection range (50) which is variably controllable by an electronic windowing technique.

11. The device according to claim 1, wherein the light pulses transmitted from the pulse source (12) form a beam (14) that is separated and substantially parallel to a beam (22) formed by light pulses that have been reflected in the sweep sector and that have been re-directed by the receiver deflection means (24) to the photodetection means (42).

12. The device according to claim 1, further comprising a transmitter lens (16) adapted to form of transmitted light pulses a transmitted beam (14).

13. The device according to claim 1, further comprising a receiver lens (40) adapted to focus to the photodetection means (42) a received beam (22) of light pulses that have been re-directed by the receiver deflection means (24).

14. The device according to claim 1, further comprising a reflector means (30) adapted to reflect the beam (14) of transmitted pulses onto the photodetection means (42) at instances when the transmitted pulses are not re-directed into the sweep sector by the transmitter deflection means (20), so as to allow measuring a known detection range as a reference for the light scanner device.

15. The device according to claim 14, wherein the reflector means (30) is a retro-reflector or a light pipe adapted to reverse a traveling direction of the pulses transmitted by the pulse source (12).

16. A door sensor system (90) for detecting a target object (56) in and/or near a door comprising a door opening (96), and at least one movable door element (76;

76-1, 76-2, 76-3, 76-4), the system comprising at least one light scanner device (10) according to claim 1.

17. A door sensor system according to claim 16, wherein the scanner device (10) is arranged such that the scanned areas (59) is in a vertical direction.

18. The door sensor system according to claim 17, wherein the light scanner device (10) is adapted such the transmitter deflection means (20) provide vertical scanned areas (59) and by the use of the multi-facet mirror additional tilted scanned areas (59) extend substantially horizontally near the door opening and the door elements and at a predetermined height above or on a ground (80).

19. The door sensor system according to claim 16, comprising at least one light scanner device (10) associated with the door opening (96) to survey the whole surface of the door opening.

20. Door sensor system for a door with movable elements wherein at least one light scanner device (10) according to claim 1 is associated with one of the movable door elements (76;

76-1, 76-2, 76-3, 76-4).

21. The system according to claim 20, wherein at least one light scanner device (10) is associated with each movable door element (76;

76-1, 76-2, 76-3, 76-4).

22. The system according to claim 16, wherein the scanned area (59) has a scanning length (58) that is directed substantially parallel to the door element (76;

76-1, 76-2, 76-3, 76-4).

23. The system according to claim 22, adapted such that the scanning length (58) can be dynamically varied to extend along and not project beyond the door element (76;

76-1, 76-2, 76-3, 76-4) when the door element is between door frame elements (72;

78), and to project beyond the door element when the door element is not between said door frame elements.

24. The system according to claim 16, wherein the light scanner device transmits and receives non-visible light pulses, and the door sensor system further comprises an illumination means adapted to emit visible light so as to visibly illuminate the scanned area (59).

25. The system according to claim 16, further comprising adjustment means for adjusting the orientation of the door sensor device such that a position of the scanned area can be aligned with respect to the door elements (76;

76-1, 76-2, 76-3, 76-4).

26. The system according to claim 25, wherein the adjustment means comprises a screw (62, 64, 66, 68) adapted to adjust the tilt angle of the sweep sector.

27. The system according to claim 16, comprising a mounting bracket means (94) adapted such that the system can be mounted to a door frame element (70, 72, 78) in at least three different angular positions (92-1, 92-2, 92-3) corresponding to at least three different tilt angles of the sweep sector.

29. Usage of a light scanner device (10) in a door sensor system (90) for detecting a target object (56) in and/or near a door comprising a door opening (96), and at least one movable door element (76;

76-1, 76-2, 76-3, 76-4) characterized in that the device (10) is a device (10) according to claim 1.

30. Usage of a light scanner device (10) in a door sensor system (90) for detecting a target object (56) in and/or near a door comprising a door opening (96), and at least one movable door element (76;

76-1, 76-2, 76-3, 76-4) characterized in that the door sensor system (90) is a system (90) according to claim 16.

28. Usage of a light scanner device (10) in a door sensor system (90) for detecting a target object (56) in and/or near a door comprising a door opening (96), and at least one movable door element (76;

76-1, 76-2, 76-3, 76-4), the device (10) comprising;

a pulse source (12) adapted to transmit light pulses,

a transmitter deflection means (20) adapted to sweep the transmitted light pulses in variable sweep directions across a sweep sector,

a photodetection means (42) adapted to detect received light pulses that have been reflected in the sweep sector,

a receiver deflection means (24) adapted to re-direct light pulses that have been reflected in the sweep plane (15) to the photodetection means (42), wherein the device (10) is arranged such that the scanned area (59) is in a vertical or nearly vertical direction.