Vehicular driver monitoring system with camera disposed behind prismatic mirror element of interior rearview mirror assembly
A vehicular cabin monitoring system includes an interior rearview mirror assembly having a mirror head that accommodates a prismatic mirror reflective element. A camera is accommodated by the mirror head. The mirror reflective element is adhesively attached at a mirror back plate of the mirror head. An optically clear adhesive (OCA) and a neutral density (ND) filter are disposed between the mirror back plate and a mirror reflector coating disposed at a rear side of the mirror reflective element. The camera views through (i) the OCA, (ii) the ND filter, (iii) the mirror reflector coating of the mirror reflective element, and (iv) the glass substrate of the mirror reflective element. With the interior rearview mirror assembly attached at an interior portion of a vehicle, image data captured by the camera is processed at an electronic control unit (ECU) for a cabin monitoring function.
1. A vehicular cabin monitoring system, the vehicular cabin monitoring system comprising:
an interior rearview mirror assembly comprising a mirror head adjustably disposed at a mounting structure, wherein the mounting structure is configured to attach at an interior portion of a vehicle equipped with the vehicular cabin monitoring system, and wherein the mirror head comprises a prismatic mirror reflective element;
a camera accommodated by the mirror head;
wherein the prismatic mirror reflective element comprises a wedge-shaped glass substrate and a mirror reflector coating disposed at a rear side of the wedge-shaped glass substrate;
wherein the prismatic mirror reflective element is adhesively attached at a mirror back plate of the mirror head;
wherein an optically clear adhesive (OCA) and a neutral density (ND) filter are disposed between the mirror back plate and the mirror reflector coating disposed at the rear side of the prismatic mirror reflective element;
wherein the camera views through (i) the OCA, (ii) the ND filter, (iii) the mirror reflector coating of the prismatic mirror reflective element and (iv) the wedge-shaped glass substrate of the prismatic mirror reflective element;
an electronic control unit (ECU) comprising electronic circuitry and associated software;
wherein the electronic circuitry of the ECU comprises an image processor for processing image data captured by the camera; and
wherein, with the mounting structure attached at the interior portion of the vehicle, image data captured by the camera is processed at the ECU for a cabin monitoring function.
2. The vehicular cabin monitoring system of claim 1 , wherein the OCA is coupled with the ND filter.
3. The vehicular cabin monitoring system of claim 1 , wherein the OCA is tinted.
4. The vehicular cabin monitoring system of claim 1 , further comprising a light emitter accommodated by the mirror head and operable, when electrically powered to emit light, to emit near infrared (NIR) light.
5. The vehicular cabin monitoring system of claim 4 , wherein the light emitter is disposed within the mirror head and behind the prismatic mirror reflective element, and wherein the light emitter, when electrically powered to emit light, emits light that passes through the prismatic mirror reflective element.
6. The vehicular cabin monitoring system of claim 5 , wherein the light emitter, when electrically powered to emit light, emits light that passes through (i) the OCA, (ii) the ND filter, (iii) the mirror reflector coating of the prismatic mirror reflective element and (iv) the wedge-shaped glass substrate of the prismatic mirror reflective element.
7. The vehicular cabin monitoring system of claim 4 , wherein the light emitter comprises a plurality of light emitting diodes (LEDs).
8. The vehicular cabin monitoring system of claim 4 , wherein the ECU is disposed within the mirror head.
9. The vehicular cabin monitoring system of claim 4 , wherein the ECU is disposed in the vehicle remote from the mirror head.
10. The vehicular cabin monitoring system of claim 1 , wherein the ND filter is disposed between the OCA and the mirror back plate.
11. The vehicular cabin monitoring system of claim 1 , wherein the mirror reflector coating of the prismatic mirror reflective element comprises a coating stack comprising a plurality of layers of at least partially reflective material.
12. The vehicular cabin monitoring system of claim 11 , wherein the coating stack comprises alternating layers of Nb 2 O 5 and SiO 2 .
13. The vehicular cabin monitoring system of claim 11 , wherein the coating stack comprises five layers.
14. The vehicular cabin monitoring system of claim 1 , wherein a near infrared (NIR) light transmissive coating is disposed between the mirror reflector coating of the prismatic mirror reflective element and the mirror back plate, and wherein the NIR light transmissive coating at least partially transmits NIR light incident at the prismatic mirror reflective element and at least partially attenuates visible light incident at the prismatic mirror reflective element, and wherein the camera views through the NIR light transmissive coating.
15. The vehicular cabin monitoring system of claim 1 , wherein a chromatic coating is disposed at the mirror reflector coating of the prismatic mirror reflective element, and wherein the chromatic coating at least partially reflects visible light incident at the prismatic mirror reflective element, and wherein the camera views through an aperture of the chromatic coating.
16. The vehicular cabin monitoring system of claim 15 , wherein the chromatic coating comprises a gradient portion at or near the aperture.
17. The vehicular cabin monitoring system of claim 1 , wherein the camera is at least partially aligned with an aperture of the mirror back plate of the mirror head.
18. The vehicular cabin monitoring system of claim 17 , wherein the mirror back plate comprises a chamfer circumscribing the aperture.
19. The vehicular cabin monitoring system of claim 18 , wherein the chamfer comprises a recessed continuous surface.
20. The vehicular cabin monitoring system of claim 1 , wherein the vehicular cabin monitoring system, based on processing of image data at the ECU, removes multiple reflection artifacts from the captured image data.
21. The vehicular cabin monitoring system of claim 1 , wherein the prismatic mirror reflective element is adhesively attached at the mirror back plate via adhesive tape.
22. The vehicular cabin monitoring system of claim 1 , wherein the prismatic mirror reflective element is adhesively attached at the mirror back plate via adhesive foam tape.
23. The vehicular cabin monitoring system of claim 22 , wherein the camera is at least partially aligned with an aperture of the adhesive foam tape.
24. The vehicular cabin monitoring system of claim 23 , wherein the mirror reflector coating of the prismatic mirror reflective element comprises a discontinuous pattern that at least partially extends along the aperture of the adhesive foam tape.
25. The vehicular cabin monitoring system of claim 1 , wherein the cabin monitoring function comprises a driver monitoring function.
26. The vehicular cabin monitoring system of claim 1 , wherein the cabin monitoring function comprises an occupant monitoring function.
27. A vehicular cabin monitoring system, the vehicular cabin monitoring system comprising:
an interior rearview mirror assembly comprising a mirror head adjustably disposed at a mounting structure, wherein the mounting structure is configured to attach at an interior portion of a vehicle equipped with the vehicular cabin monitoring system, and wherein the mirror head comprises a prismatic mirror reflective element;
a camera accommodated by the mirror head;
a light emitter accommodated by the mirror head and operable, when electrically powered to emit light, to emit near infrared (NIR) light;
wherein the light emitter is disposed behind the prismatic mirror reflective element, and wherein the light emitter, when electrically powered to emit light, emits light that passes through the prismatic mirror reflective element;
wherein the prismatic mirror reflective element comprises a wedge-shaped glass substrate and a mirror reflector coating disposed at a rear side of the wedge-shaped glass substrate;
wherein the prismatic mirror reflective element is adhesively attached at a mirror back plate of the mirror head;
wherein an optically clear adhesive (OCA) and a neutral density (ND) filter are disposed between the mirror back plate and the mirror reflector coating disposed at the rear side of the prismatic mirror reflective element;
wherein the ND filter is disposed between the OCA and the mirror back plate;
wherein the camera views through (i) the OCA, (ii) the ND filter, (iii) the mirror reflector coating of the prismatic mirror reflective element and (iv) the wedge-shaped glass substrate of the prismatic mirror reflective element;
an electronic control unit (ECU) comprising electronic circuitry and associated software;
wherein the electronic circuitry of the ECU comprises an image processor for processing image data captured by the camera, and wherein the ECU is disposed within the mirror head; and
wherein, with the mounting structure attached at the interior portion of the vehicle, image data captured by the camera is processed at the ECU for a cabin monitoring function.
28. The vehicular cabin monitoring system of claim 27 , wherein the light emitter, when electrically powered to emit light, emits light that passes through (i) the OCA, (ii) the ND filter, (iii) the mirror reflector coating of the prismatic mirror reflective element and (iv) the wedge-shaped glass substrate of the prismatic mirror reflective element.
29. The vehicular cabin monitoring system of claim 27 , wherein the mirror reflector coating of the prismatic mirror reflective element comprises a coating stack comprising a plurality of layers of at least partially reflective material.
30. The vehicular cabin monitoring system of claim 29 , wherein the coating stack comprises alternating layers of Nb 2 O 5 and SiO 2 .
31. The vehicular cabin monitoring system of claim 27 , wherein the cabin monitoring function comprises at least one selected from the group consisting of (i) a driver monitoring function and (ii) an occupant monitoring function.
32. A vehicular cabin monitoring system, the vehicular cabin monitoring system comprising:
an interior rearview mirror assembly comprising a mirror head adjustably disposed at a mounting structure, wherein the mounting structure is configured to attach at an interior portion of a vehicle equipped with the vehicular cabin monitoring system, and wherein the mirror head comprises a prismatic mirror reflective element;
a camera accommodated by the mirror head;
wherein the prismatic mirror reflective element comprises a wedge-shaped glass substrate and a mirror reflector coating disposed at a rear side of the wedge-shaped glass substrate;
wherein the mirror reflector coating of the prismatic mirror reflective element comprises a coating stack comprising a plurality of layers of at least partially reflective material, and wherein the coating stack comprises alternating layers of Nb 2 O 5 and SiO 2 ;
wherein an adhesive foam tape adhesively attaches the prismatic mirror reflective element at a mirror back plate of the mirror head;
wherein the camera is at least partially aligned with respective apertures of the adhesive foam tape and the mirror back plate of the mirror head;
wherein an optically clear adhesive (OCA) and a neutral density (ND) filter are disposed between the mirror back plate and the mirror reflector coating disposed at the rear side of the prismatic mirror reflective element;
wherein the camera views through (i) the OCA, (ii) the ND filter, (iii) the mirror reflector coating of the prismatic mirror reflective element and (iv) the wedge-shaped glass substrate of the prismatic mirror reflective element;
an electronic control unit (ECU) comprising electronic circuitry and associated software;
wherein the electronic circuitry of the ECU comprises an image processor for processing image data captured by the camera; and
wherein, with the mounting structure attached at the interior portion of the vehicle, image data captured by the camera is processed at the ECU for a cabin monitoring function.
33. The vehicular cabin monitoring system of claim 32 , wherein the OCA is tinted.
34. The vehicular cabin monitoring system of claim 32 , wherein the coating stack comprises five layers.
35. The vehicular cabin monitoring system of claim 32 , wherein the mirror back plate comprises a chamfer circumscribing the aperture of the mirror back plate of the mirror head.
36. The vehicular cabin monitoring system of claim 35 , wherein the chamfer comprises a recessed continuous surface.
37. The vehicular cabin monitoring system of claim 32 , wherein the mirror reflector coating of the prismatic mirror reflective element comprises a discontinuous pattern that at least partially extends along the aperture of the adhesive foam tape.
38. The vehicular cabin monitoring system of claim 32 , wherein the cabin monitoring function comprises at least one selected from the group consisting of (i) a driver monitoring function and (ii) an occupant monitoring function.