Optical module for simultaneously focusing on two fields of view
The invention relates to an optical module, comprising a semiconductor element having a surface that is sensitive to electromagnetic radiation and an objective for projecting electromagnetic radiation onto the sensitive surface of the semiconductor element (image sensor or camera chip, in particular CCD or CMOS). The objective preferably comprises at least one lens and one lens retainer. In the optical module, an optical element having two sub-areas is arranged either in the space between the objective and the sensitive surface of the semiconductor element or between individual lenses of the objective in the entire cross-section of the beam path. All electromagnetic radiation that reaches the sensitive surface of the semiconductor element passes through the optical element. A first distance range (e.g. near range) is imaged in a first area of the sensitive surface of the semiconductor element in a focused manner by a first sub-area of the optical element, and a second distance range (e.g. far range) is imaged in a second area of the sensitive surface of the semiconductor element by a second sub-area.
1. An optical module, comprising
a semiconductor element ( 4 ) having a sensitive surface ( 14 ) that is sensitive to electromagnetic radiation and
an objective ( 1 ) for projecting electromagnetic radiation onto the sensitive surface ( 14 ) of the semiconductor element ( 4 ),
characterized in that an optical element ( 11 ) having at least two plane-parallel sub-areas ( 11 a , 11 b ) of different thicknesses is arranged either in the space between the objective ( 1 ) and the sensitive surface ( 14 ) of the semiconductor element ( 4 ) or between individual lenses of the objective in the entire cross-section of the beam path, such that a first distance range ( 8 ) is imaged in a first area of the sensitive surface ( 14 ) of the semiconductor element ( 4 ) by a first sub-area ( 11 a ) of the optical element ( 11 ), and a second distance range ( 9 ) is imaged in a second area of the sensitive surface ( 14 ) of the semiconductor element ( 4 ) by a second sub-area ( 11 b ) of the optical element ( 11 ).
2. The optical module according to claim 1 , characterized in that the optical element ( 11 ) has a stepped configuration and is arranged such that a continuous surface of the optical element ( 11 ) is oriented toward the sensitive surface ( 14 ) of the semiconductor element ( 4 ).
3. The optical module according to claim 1 , characterized in that the optical element ( 11 ) has a stepped configuration and is arranged such that a stepped edge between the two sub-areas ( 11 a , 11 b ) is close to the sensitive surface ( 14 ) of the semiconductor element ( 4 ) and a continuous surface of the optical element ( 11 ) is an external surface.
4. The optical module according to claim 3 , further comprising a spacer ( 24 ) that extends in a U-shape below an exterior of a thinner one of the two sub-areas ( 11 a ).
5. The optical module according to claim 3 , characterized in that a thinner one of the two sub-areas ( 11 a ) completely extends around a thicker one of the two sub-areas ( 11 b ) of the optical element ( 11 ), and further comprising a spacer ( 24 , 24 ′) that extends around an area between the sensitive surface and the optical element ( 11 ) in a frame-like manner.
6. The optical module according to claim 5 , characterized in that the spacer ( 24 ′) is configured as a frame, and further comprising a sealing compound that is surrounded by the frame for sealing the semiconductor element ( 4 ) to protect the sensitive surface ( 14 ) of the semiconductor element ( 4 ) from environmental impacts and stray light.
7. The optical module according to claim 1 , characterized in that the optical module is arranged in the interior of a vehicle behind a windshield ( 5 ) of the vehicle with respect to a direction of travel, such that the optical module receives electromagnetic radiation from an exterior space outside of the vehicle.
8. The optical module according to claim 7 , characterized in that the objective ( 1 ) and the optical element ( 11 ) are adjusted such that an exterior surface of the windshield ( 5 ) facing the exterior space is imaged in a focused manner on the first area of the sensitive surface ( 14 ) of the semiconductor element ( 4 ) by the first sub-area ( 11 a ) of the optical element ( 11 ) and an area of the exterior space ahead of the vehicle is imaged on the second area of the sensitive surface ( 14 ) of the semiconductor element ( 4 ) by the second sub-area ( 11 b ) of the optical element ( 11 ).
9. The optical module according to claim 8 , characterized in that rain drops ( 6 ) and/or particles of dirt present on the exterior surface of the windshield ( 5 ) can be detected in the first area of the sensitive surface ( 14 ) of the semiconductor element ( 4 ), and an output signal of the optical module can be output to a wiper control and/or a window cleaning control of the vehicle.
10. The optical module according to claim 9 , characterized in that a capacitive rain sensor is provided in the vehicle in addition to a camera-based rain sensor formed with the optical module, and a joint evaluation unit evaluates signals from the capacitive rain sensor and the camera-based rain sensor.
11. The optical module according to claim 8 , further comprising an illumination source that provides electromagnetic radiation to illuminate an area ( 9 ) of a field of view ( 10 ) through the windshield ( 5 ) that is imaged in the first area of the sensitive surface ( 14 ) of the semiconductor element ( 4 ).
12. The optical module according to claim 11 , further comprising a flexible light-guide body that couples the electromagnetic radiation of the illumination source into the windshield ( 5 ).
13. The optical module according to claim 11 , characterized in that the electromagnetic radiation that illuminates the area ( 9 ) of the field of view ( 10 ) through the windshield ( 5 ) comprises light in an infrared wavelength range, and the second sub-area ( 11 b ) of the optical element ( 11 ) is coated with a filter that suppresses transmission in the infrared wavelength range.
14. The optical module according to claim 8 , further comprising a wedge plate arranged between the windshield ( 5 ) and the objective ( 1 ) in a field of view of the imaging of the exterior surface of the windshield ( 5 ).
15. The optical module according to claim 8 , further comprising an illumination source that provides electromagnetic radiation which is coupled into the windshield, and a decoupling element arranged in firm contact with the windshield ( 5 ), which decoupling element decouples the electromagnetic radiation coupled into the windshield such that said electromagnetic radiation is imaged in the first area of the sensitive surface ( 14 ) of the semiconductor element ( 4 ).
16. The optical module according to claim 15 , characterized in that the decoupling element covers the sub-area of the field of view of the windshield ( 5 ) that is sensed by the near-range imaging ( 9 ).
17. A method of manufacturing the optical module according to claim 1 , comprising the steps:
connecting to a carrier ( 20 ), a semiconductor element ( 4 ) having a surface ( 14 ) that is sensitive to electromagnetic radiation,
attaching on the semiconductor element ( 4 ), by a first adhesive ( 17 ), an optical element ( 11 ) having at least two sub-areas ( 11 a , 11 b ) for bifocal imaging,
sealing, by a sealing compound ( 18 ), a connection area of the carrier ( 20 ), the semiconductor element ( 4 ), the adhesive ( 17 ) and the optical element ( 11 ),
applying a second adhesive ( 25 ) to a lower surface of an objective housing ( 27 ) of an objective ( 1 ) or to the carrier ( 20 ),
placing the objective ( 1 ) onto the carrier ( 20 ) and adjusting the arrangement such that electromagnetic radiation passes through the objective ( 1 ) and the optical element ( 11 ) and reaches the sensitive surface ( 14 ) of the semiconductor element ( 4 ), and
hardening the second adhesive ( 25 ) in the adjusted arrangement of the objective ( 1 ) and the carrier ( 20 ).
18. A method of manufacturing a specific number of similar optical elements ( 11 ) each having at least two sub-areas ( 11 a , 11 b ), wherein
a first glass wafer ( 30 ) of a first thickness is provided with a corresponding number of recesses ( 29 ),
said first glass wafer ( 30 ) is covered with and connected to a second glass wafer ( 31 ) of a second thickness, and
the specific number of individual optical elements ( 11 ) having at least two plane-parallel sub-areas ( 11 a , 11 b ) of different thicknesses results from sawing ( 32 ) the combined wafer.