Optical radiation intensity sensor

• US 7,157,678 B2
• Filed: 06/24/2004
• Issued: 01/02/2007
• Est. Priority Date: 06/24/2003
• Status: Active Grant

• Current Assignee: Littelfuse Incorporated
• Original Assignee: Accel AB (Littelfuse Incorporated)
• Inventors: Maldziunas, Arvydas Antanas, Ziogas, Vidamantas
• Primary Examiner(s): PYO, KEVIN K
• Application Number:
  US10/875,628
• Publication Number:
  US 20050023466A1
• Time in Patent Office: 922 Days
• Field of Search: 250/203.4, 250/203.1, 250/203.3, 250/206.1, 250/206.2, 250/216, 250/239, 126/573, 165/42, 165/203, 236/91.F, 356/139.01, 356/141.5
• US Class Current: 250/203.4
• CPC Class Codes: B60H 1/0075 the input being solar radiation
• CPC Class Codes: G01J 1/4228 arrangements with two or more detectors, e.g. for sensitivity compensation
• CPC Class Codes: G01J 2001/4266 for measuring solar light
• CPC Class Codes: G01S 3/7861 Solar tracking systems

Abstract

A radiation intensity directional sensor includes a housing having an opening covered by a transparent or translucent lens element, an array of sensor elements sensitive to radiation, preferably to electromagnetic radiation in the visible and/or infrared range, and a shading element separating at least two of the sensor elements. The shading element at least partly blocks light from impinging directly on one of two sensing elements separated by the shading element. The array of sensor elements is thereby arranged for producing output signals from the at least two separated sensor elements having different amplitudes whereby the difference in amplitude is used for estimating the position of a light source in relation to the sensor housing.

Claims

1. A photo radiation intensity sensor comprising a housing having a transparent or translucent portion, and at least one optical sensor element sensitive to radiation, said at least one optical sensor element being arranged for producing output signals which are used for estimating the sun radiation heating impact, wherein the housing includes a chamber containing a diffusive compound that is a potting, which compound is positioned between said housing and said at least one optical sensor element.

2. A photo radiation intensity sensor according to claim 1, wherein the compound is flooding the chamber.

3. A photo radiation intensity sensor according to claim 2, wherein said sensor includes an array of sensor elements which are arranged to detect both the direction and the intensity of the radiation source.

4. A photo radiation intensity directional sensor according to claim 3, wherein said sensor includes a shading element separating at least two of said sensor elements, whereby said shading element is arranged to prevent exposure of radiation of said at least two sensor elements separated by said shading element to a degree depending of the position of the photo radiation intensity directional sensor in relation to a source of photo radiation, said shading element is thereby arranged for creating differences in output amplitudes from said at least two sensor elements which difference in amplitude is used for estimating the position of the source of radiation.

5. A photo radiation intensity directional sensor according to claim 4, wherein said shading element divides said chamber into at least two sub compartments, each containing one or several sensor elements.

6. A photo radiation intensity directional sensor according to claim 5, wherein said chamber includes a bottom region forming part of said at least two sub compartments, where said bottom region is vertically arranged below an upper edge of said shading element.

7. A photo radiation intensity directional sensor according to claim 5, wherein said sensor elements are positioned inside said chamber and being exposed to said diffusive compound.

8. A photo radiation intensity directional sensor according to claim 3, wherein said photo radiation intensity sensor includes a radiation filter transparent to a defined frequency interval, which radiation filter is arranged to block radiation outside said frequency interval from impinging on said sensor elements.

9. A photo radiation intensity directional sensor according to claim 8, wherein said radiation filter is constituted by said compound.

10. A photo radiation intensity directional sensor according to claim 8, wherein said radiation filter includes a lens element.

11. A photo radiation directional intensity sensor according to claim 3, wherein said sensor elements are sensitive to infrared and/or visible light.

12. A photo radiation intensity directional sensor according to claim 1, wherein said compound is arranged to preserve said sensor element from oxidising.

13. A photo radiation intensity directional sensor according to claim 12, wherein said sensor elements are positioned on a printed circuit board which carries further electronic circuits, wherein said printed circuit board is positioned at least partly inside said chamber such that said electronic circuits and sensor elements are protected from negative influence on the environment by the diffusive compound.

14. A photo radiation directional intensity sensor according to claim 1, wherein said diffusive compound is a liquid or a gel.

15. A photo radiation intensity directional sensor according to claim 14, wherein said sensor includes a shading element separating at least two of said sensor elements, so that said shading element is arranged to prevent exposure of radiation of said at least two sensor elements separated by said shading element to a degree depending of the position of the photo radiation intensity directional sensor in relation to a source of photo radiation, said shading element is thereby arranged for creating differences in output amplitudes from said at least two sensor elements which difference in amplitude is used for estimating the position of the source of radiation.

16. A photo radiation intensity sensor according to claim 1, wherein said sensor includes an array of sensor elements which are arranged to detect both the direction and the intensity of the radiation source.

17. A photo radiation intensity directional sensor according to claim 1, wherein said photo radiation intensity sensor includes at least two sensor elements, and further comprises a shading element that separates at least two of said sensor elements so that said shading element is arranged to prevent exposure of radiation of said at least two sensor elements separated by said shading element to a degree depending of the position of the photo radiation intensity directional sensor in relation to a source of photo radiation, each of said at least two sensor elements being mounted on said shading element.

18. The photo radiation intensity directional sensor according to claim 1, wherein the diffusive compound acts to a diffuser to transmit light to the optical sensor element.

19. A photo radiation intensity directional sensor comprising a housing having a transparent or translucent portion, and at least one sensor element sensitive to radiation, said at least one sensor element being arranged for producing output signals which are used for estimating the sun radiation heating impact, wherein the housing includes a chamber containing a diffusive compound that is a potting, which compound is positioned between said housing and said at least one sensor element,

wherein the compound is flooding the chamber,

wherein said sensor includes an array of sensor elements which are arranged to detect both the direction and the intensity of the radiation source,

wherein said sensor includes a shading element separating at least two of said sensor elements, whereby said shading element is arranged to prevent exposure of radiation of said at least two sensor elements separated by said shading element to a degree depending of the position of the photo radiation intensity directional sensor in relation to a source of photo radiation, said shading element is thereby arranged for creating differences in output amplitudes from said at least two sensor elements which difference in amplitude is used for estimating the position of the source of radiation,

wherein said shading element divides said chamber into at least two sub compartments, each containing one or several sensor elements, and

wherein said chamber includes a top region forming part of said at least two sub compartments, where said top region is vertically arranged in relation to said shading element such that said shading element does not prevent photo radiation from impinging on at least a portion of each sub compartment in said top region.

20. A photo radiation intensity directional sensor according to claim 19, wherein said top region is positioned vertically above said shading element.

21. A photo radiation intensity directional sensor according to claim 19, wherein said chamber includes a bottom region forming part of said at least two sub compartments, where said bottom region is vertically arranged below an upper edge of said shading element.

22. A photo radiation intensity directional sensor according to claim 19, wherein said chamber includes a bottom region forming part of said at least two sub compartments, where said bottom region is vertically arranged below an upper edge of said shading element.

23. A photo radiation intensity sensor comprising a housing having a transparent or translucent portion, and at least one sensor element sensitive to radiation, said at least one sensor element being arranged for producing output signals which are used for estimating the sun radiation heating impact, wherein the housing includes a chamber containing a diffusive compound that is a potting, which compound is positioned between said housing and said at least one sensor element, wherein said sensor element includes a shading element, and wherein said chamber includes a top region forming part of least two sub compartments, said top region being vertically arranged in relation to said shading element such that said shading element does not prevent photo radiation from impinging on at least a portion of each sub compartment in said top region.