Optical module having a multifocal optical system with an additional optical element for covering a far range and a near range in one image

• US 8,541,732 B2
• Filed: 12/17/2009
• Issued: 09/24/2013
• Est. Priority Date: 12/23/2008
• Status: Expired due to Fees

• Current Assignee: ADC GmbH (TE Connectivity Ltd. (United Kingdom))
• Original Assignee: ADC GmbH (TE Connectivity Ltd. (United Kingdom))
• Inventors: Rothenhaeusler, Konrad
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US13/140,957
• Publication Number:
  US 20110253917A1
• Time in Patent Office: 1,377 Days
• Field of Search: 250/208.1, 250/227.25, 250/216, 250/573, 340/602, 340901-903, 318/DIG.2, 318/444, 318/483, 351206-211
• US Class Current: 250/208.1
• CPC Class Codes: B60S 1/0844 including a camera
• CPC Class Codes: G01N 2021/157 Monitoring by optical means
• CPC Class Codes: G02B 2027/0138 comprising image capture systems, e.g. camera
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle

Abstract

The invention relates to an optical module having a semiconductor element (4) with a surface that is sensitive to electromagnetic radiation and with an objective lens (1) for the projection of electromagnetic radiation onto the sensitive surface of the semiconductor element (4), in particular for the use thereof in motor vehicles. An additional optical element (11) is arranged in a defined partial volume in the space between the objective lens (1) and the sensitive surface of the semiconductor element (4) so that, by the additional optical element (11), a first distance range (8) is imaged in a first region of the sensitive surface of the semiconductor element (4) and a second distance range (9) is imaged in a second region of the visual range where the additional optical element (11) is not located.

Claims

1. An optical module, comprising

a semiconductor element (4) with a sensitive surface that is sensitive to electromagnetic radiation,

an objective lens (1) adapted and arranged for the projection of electromagnetic radiation onto the sensitive surface of the semiconductor element (4), and

an additional optical element (11) arranged in a defined partial volume in a space between the objective lens (1) and the sensitive surface of the semiconductor element (4),

wherein the objective lens (1) is positioned in such a manner and the additional optical element (11) is dimensioned and arranged in such a manner so that an optical far range (8) of the visual range (10) of the optical module is imaged by the additional optical element (11) onto a first region of the sensitive surface of the semiconductor element (4) and an optical near range (9) of the visual range (10) of the optical module is imaged by the objective lens onto a second region of the sensitive surface of the semiconductor element where the additional optical element (11) is not located.

2. The optical module according to claim 1, characterized in that a first index of refraction of the additional optical element (11) is higher than a second index of refraction of a medium surrounding the additional optical element (11).

3. The optical module according to claim 1, characterized in that the additional optical element (11) is a plane-parallel transparent plate.

4. The optical module according to claim 3, characterized in that the plane-parallel transparent plate (11) is made of a synthetic plastic material.

5. The optical module according to claim 1, characterized in that the additional optical element (11) is a part of a diverging lens, is a microlens array with diverging lenses or is a diffractive microlens array.

6. The optical module according to claim 1, characterized in that the additional optical element (11) comprises at least two plane-parallel regions of different thicknesses.

7. The optical module according to claim 1, characterized in that the additional optical element (11) comprises at least two regions respectively comprising different materials having different indices of refraction.

8. The optical module according to claim 1, characterized in that the additional optical element (11) is wedge-shaped.

9. The optical module according to claim 1, adapted and arranged so that the additional optical element (11) can be cyclically introduced into the space between the objective lens (1) and the sensitive surface of the semiconductor element (4).

10. The optical module according to claim 1, characterized in that the additional optical element (11) comprises, in the partial volume, a liquid medium having a first index of refraction higher than a second index of refraction of a surrounding medium that surrounds the additional optical element.

11. The optical module according to claim 1, characterized in that the additional optical element (11) is dimensioned in such a manner so that the first region of the sensitive surface of the semiconductor element is larger than the second region.

12. The optical module according to claim 1, further comprising a coating by which reflections can be avoided, provided on at least one side of the additional optical element (11).

13. The optical module according to claim 1, further comprising a coating for filtering electromagnetic radiation in a defined wavelength range, provided on at least one side of the additional optical element (11).

14. A vehicle including an optical module according to claim 1, characterized in that the optical module is arranged in a passenger compartment of the vehicle behind a windscreen (5) of the vehicle, and the visual range of the optical module covers a region outside the vehicle in a direction of motion of the vehicle.

15. The vehicle according to claim 14, characterized in that the objective lens (1) of the optical module is positioned in such a manner so that an outer surface of the windscreen (5) is sharply imaged on the second region of the sensitive surface of the semiconductor element (4).

16. The vehicle according to claim 15, further comprising an evaluation unit in which the image from the second region of the sensitive surface of the semiconductor element (4) is evaluated, wherein rain and/or dirt particles on the windscreen (5) are detected and an output signal of the evaluation unit is outputted to a windscreen wiper control system and/or a windscreen washer control system of the vehicle.

17. The vehicle according to claim 14, further comprising an illumination source that illuminates the optical near range (9) of the visual range (10) through the windscreen (5) which is imaged in the second region of the sensitive surface of the semiconductor element (4).

18. The vehicle according to claim 17, characterized in that radiation of the illumination source is coupled into the windscreen (5) via a flexible light guide body.

19. The vehicle according to claim 17, characterized in that the illumination source illuminates the optical near range (9) of the visual range (10) through the windscreen (5) with light in an infrared wavelength range and the additional optical element (11) is coated with a filter that suppresses transmission in the infrared wavelength range.

20. The vehicle according to claim 14, wherein the optical module forms a camera-based rain sensor, and the vehicle further comprises a capacitive rain sensor and a shared evaluation unit that evaluates signals from the capacitive rain sensor and from the camera-based rain sensor.

21. The vehicle according to claim 14, further comprising a camera wedge arranged between the windscreen (5) and the objective lens (1) in an object-side beam path of the optical near range (9).

22. The vehicle according to claim 21, characterized in that the camera wedge is coated with a filter coating that suppresses particular wavelength ranges.

23. The vehicle according to claim 21, characterized in that an upper, face of the camera wedge is blackened for the suppression of stray light.

24. The vehicle according to claim 18, further comprising a decoupling element that firmly contacts the windscreen (5) and decouples the radiation coupled into the windscreen so that the radiation is imaged in the second region of the sensitive surface of the semiconductor element (4).

25. The vehicle according to claim 24, characterized in that the decoupling element is coated with a filter coating that suppresses particular wavelength ranges.

26. The vehicle according to claim 24, characterized in that a side of the decoupling element which faces the objective lens (1) has a mat surface.

27. The vehicle according to claim 24, characterized in that the decoupling element covers an area of the windscreen (5) through which the optical near range is imaged.

28. A method for calibrating a distance and a position between the windscreen (5) and the optical module in the vehicle according to claim 10, characterized in that the optical module forms, on the sensitive surface of the semiconductor element (4), a focused image of a target mark arranged on the windscreen (5) so that an evaluation unit measures a change of the position of the windscreen (5) relative to an optical axis of the optical module compared to a stored starting position.