Handsensor for authenticity identification of signets on documents

• US 6,784,441 B2
• Filed: 07/03/2001
• Issued: 08/31/2004
• Est. Priority Date: 07/03/2000
• Status: Expired due to Fees

• Current Assignee: Bundesdruckerei GmbH (Government of Germany)
• Original Assignee: Baumer Electric AG (Baumer Holding AG), Bundesdruckerei GmbH (Government of Germany)
• Inventors: Paeschke, Manfred, Weber, Uwe, Ahlers, Benedikt, Franz-Burgholz, Arnim, Gutmann, Roland, Bailleu, Anett, Halter, Peter, Zerbel, Hans
• Primary Examiner(s): Hannaher, Constantine
• Application Number:
  US09/899,742
• Publication Number:
  US 20030030012A1
• Time in Patent Office: 1,155 Days
• Field of Search: 250/458.1
• US Class Current: 250/458.1
• CPC Class Codes: G07D 7/121 Apparatus characterised by sensor details
• CPC Class Codes: G07D 7/128 Viewing devices

Abstract

A manually controlled sensor for authenticity identification of luminescent identification features on documents is described, in which the identification feature is illuminated with an excitation wavelength and may respond at a different wavelength, with the response wavelength being detected and evaluated by a radiation receiver. In order to improve the sensitivity and to comply with the safety at work regulations, a focused beam (31, 32), which is emitted from a beam source (1), is converted by focusing optics (2, 3) in such a manner that a scanning bar (22), which is approximately in the form of a line, is projected on the surface of the object (5) to be investigated, which causes the identification region (21) which is arranged on the object (5) to fluoresce in a luminescent manner in at least one subregion, and the luminescence signal produced in this way is passed via detection optics (9, 9′, 10) to an evaluation unit (11), which evaluates the luminescence signal. The sensor is intended to be classified in laser class 3A.

Claims

1. A sensor for authenticity identification of a luminescent identification feature on a document comprising:

a beam source and a focusing optics for illuminating the identification feature with a focused beam at a wavelength in the form of an excitation wavelength to optically excite at least a subregion of the identification feature and wherein the identification feature may respond in an optical response signal at a same or different wavelength in the form of a response wavelength,

a radiation receiver for detecting and evaluating the response wavelength,

wherein the focused beam is emitted from the beam source and is converted by focusing optics in such a manner that a scanning bar approximately in the form of a line is projected on the surface of the document and having a detection optics and an evaluation unit,

wherein the optical response signal is passed via detection optics to the evaluation unit which evaluates the optical response signal, and

wherein the sensor is a manually controlled sensor, the beam source is formed as a laser, and the focusing optics has a lineoptics comprising a cylindrical lens,

wherein the focused beam is a laser focused beam, which is produced by the laser passed through the lineoptics and is imaged differently in the X-direction and Y-direction on the document.

2. The sensor as claimed in claim 1, wherein the sensor has a head surface and a proximity identification, which switches on a laser only when the document is located closely in front of and touching an outlet window in the head surface.

3. The sensor as claimed in claim 2, wherein the proximity identification operates without making contact.

4. The sensor as claimed in claim 3, wherein an external light identification, which obviates switching on of the laser when external light or ambient light is being received by the external light identification, is integrated in the arrangement for proximity identification without making contact.

5. The sensor as claimed in claim 2 or 3, wherein the proximity identification reacts to diffuse reflection on the surface of the document.

6. The sensor as claimed in claim 2, wherein the proximity identification operates by touching the document.

7. The sensor as claimed in claim 2, wherein, in addition to the proximity identification, a manually operated pushbutton is provided, which is coupled to the proximity identification or whose previous operation is a prior condition for activation of the laser after identification of the proximity within a short time window.

8. A sensor as claimed in claim 1, wherein the response wavelength is a shorter, longer or equal wavelength compared to the excitation wavelength.

9. The sensor as claimed in claim 8, wherein the largest angles of the focused beams in the X-plane or Y-plane reach an angle of more than +/−

10°

to the optical axis.

10. The sensor as claimed in claim 1, wherein the focusing in the X-plane and Y-plane is produced at a different height above the document.

11. The sensor as claimed in claim 10, wherein the laser focused beam is focused directly on the document in the X-plane.

12. The sensor as claimed in claim 1, wherein the laser is classified in laser class 3A.

13. The sensor as claimed in claim 1, wherein the laser is pulsed.

14. The sensor as claimed in claim 13, wherein, in order to identify the identification feature on a document, the sensor is adapted to use the up-conversion effect, wherein the excitation wavelength is longer than the response wavelength.

15. The sensor as claimed in claim 13, wherein in order to identify the identification feature on a document, the sensor is adapted to use the down-conversion effect, wherein the response wavelength is longer than the excitation wavelength.

16. The sensor as claimed in claim 13, wherein in order to identify the identification feature on a document, the sensor is adapted to use the fluorescence effect, wherein the excitation wavelength is the same wavelength as the response wavelength.

17. The sensor as claimed in claim 16, wherein a pulse response is delayed in time with respect to an excitation pulse.

18. The sensor as claimed in claim 13, wherein the laser has a pulse repetition frequency and a high-pass, low-pass or bandpass filter is provided in a receiver electronics, which pass only the pulse repetition frequency of the laser.

19. The sensor as claimed in claim 13, wherein the response signal is averaged over a number of laser pulses.

20. The sensor as claimed in claim 1, wherein the detection optics is a wide-aperture receiving optics with an aperture ratio of virtually 1 or less.

21. The sensor as claimed in claim 1, wherein the laser is formed as a laser diode.

22. The sensor as claimed in claim 1, wherein the evaluation unit is formed as a receiving element.

23. The sensor as claimed in claim 22, wherein the receiving element is formed as a photodiode or an avalanche photodiode or a photomultiplier.

24. The sensor as claimed in claim 22, wherein the receiving element (11) provides an external light identification, which obviates switching on of the laser when external light or ambient light is being received by the external light identification.

25. The sensor as claimed in claim 1, wherein the cylindrical lens is a focusing cylindrical lens.

26. The sensor as claimed in claim 1, wherein the cylindrical lens is a divergent cylindrical lens.

27. The sensor as claimed in claim 1, wherein the cylindrical lens has a aspherical, conical surface.

28. The sensor as claimed in claim 1, wherein the lineoptics comprises defractive optical elements or a Fresnel lens or a sinusoidal surface.

29. The sensor as claimed in claim 1, wherein the lineoptics comprises a convergent lens.

30. The sensor as claimed in claim 1, wherein an external light identification is provided which obviates switching on of the laser when external light or ambient light is being received by the external light identification.

31. The sensor as claimed in claim 30, wherein the external light identification is integrated in a reception path of the authenticity identification of the identification feature.

32. The sensor as claimed in claim 1, wherein optical filters pass only a desired wavelength of the response signal.

33. The sensor as claimed in claim 1 wherein the sensor has a housing and one or more batteries are arranged in the housing.