Spectral detector
AssigneeKoninklijke Philips N.V.
InventorsRifat A. M. Hikmet, Eduard J. Meijer, Ties Van Bommel
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Abstract
The invention relates to a spectral detector for measuring properties of light over portions of the electromagnetic spectrum including cholesteric liquid crystal material and switching means capable of varying the pitch of the helix of the cholesteric liquid crystal material, so that the position of the transmission wavelength band is adjusted in response to the switching means. The spectral detector may further include at least one light direction selecting structure for selecting light incident on the spectral detector having a certain angle of incidence. This invention also relates to a lighting system including the spectral detector of the invention.
Claims19
A spectral detector including:
- at least one layer including a cholesteric liquid crystal mixture;
- at least one switching means operatively coupled to at least one of the layers, for varying the helical pitch of the chiral component in the cholesteric liquid crystal mixture included in the layer;
- and
- a photo detector array coupled to at least one of the layers, wherein the at least one cholesteric liquid crystal layer coupled to the at least one switching means is arranged such that the cholesteric liquid crystal mixture in at least one portion of said cholesteric crystal layer has a different helical pitch than the helical pitch of cholesteric liquid crystal mixture in other portions said of cholesteric liquid crystal layer.
A lighting system including:
- a control unit;
- at least one light module, including at least one light source, wherein the at least one light module operates in accordance with a plurality of parameters;
- and
- a spectral detector, including
- at least one layer including, a cholesteric liquid crystal mixture;
- at least one switching means operatively coupled to at least one of the layers, for varying the helical pitch of the chiral component in the cholesteric crystal mixture included in the layer;
- and
- a photo detector array coupled to at least one of the layers;
- wherein the control unit is configured to perform at least one measurement using the spectral detector and control at least one parameter of the at least one light module based on said at least one measurement.
A spectral detector including:
- at least one layer including a cholesteric liquid crystal mixture;
- at least one switching means operatively coupled to at least one of the layers, for varying the helical pitch of the chiral component in the cholesteric liquid crystal mixture included in the layer;
- a photo detector array coupled to at least one of the layers;
- and
- at least one phase retardation layer.
A spectral detector including:
- at least one layer including a cholesteric liquid crystal mixture;
- at least one switching means operatively coupled to at least one of the layers, for varying the helical pitch of the chiral component in the cholesteric liquid crystal mixture included in the layer;
- a photo detector array coupled to at least one of the layers;
- and
- a light direction selection layer, wherein the light direction selection layer comprises a plurality of portions configured such that at least one portion is arranged such that it is capable of selecting light incident on the spectral detector having a different direction compared to other portions of the light direction selection layer.
Dependencies are inferred from the claim text.