摘要:
A camera flash comprises a light guide (9) arranged to extract light at least through one surface; and one or more light sources (8) arranged, in use, to emit light into the lightguide. Each light source is an LED or a laser diode. The camera flash is connectable, in use, to drive circuitry, the drive circuitry being for driving the light source(s) (8) to emit a pulse of light. The waveguide spreads out the light from the light source(s), so that a flash of light from the camera flash does not present a safety risk, while minimising loss of the light from the light source(s). The camera flash can thus provide a high overall optical output, spread over an extended area (as defined by the waveguide). The lightguide may for example be disposed around a camera module (19) of a mobile telephone camera.
摘要:
A liquid crystal display device comprises: a layer of a chiral liquid crystal material disposed between first and second substrates (1,1'); and means for applying a voltage (6,6',7) across the liquid crystal layer. A first region of the liquid crystal layer is an active region (10) for display and a second region of the liquid crystal layer is a nucleation region (11) for generating a desired liquid crystal state in the first region when a voltage is applied across the liquid crystal layer. The ratio of the thickness d of the liquid crystal layer to the pitch p of the liquid crystal material has a first value (d/p) A in the first region of the liquid crystal layer and has a second value (d/p) N different from the first value in the second region of the liquid crystal layer. The value (d/p) N of the ratio of the thickness d of the liquid crystal layer to the pitch p of the liquid crystal material in the second region of the liquid crystal layer is selected such that, when no voltage is applied across the liquid crystal layer, the liquid crystal state stable in the second region of the liquid crystal layer is topologically equivalent to the desired liquid crystal state under application of a voltage.
摘要:
A camera flash comprises a light guide (9) arranged to extract light at least through one surface; and one or more light sources (8) arranged, in use, to emit light into the lightguide. Each light source is an LED or a laser diode. The camera flash is connectable, in use, to drive circuitry, the drive circuitry being for driving the light source(s) (8) to emit a pulse of light. The waveguide spreads out the light from the light source(s), so that a flash of light from the camera flash does not present a safety risk, while minimising loss of the light from the light source(s). The camera flash can thus provide a high overall optical output, spread over an extended area (as defined by the waveguide). The lightguide may for example be disposed around a camera module (19) of a mobile telephone camera.
摘要:
A low concentration solar apparatus for collecting solar radiation and concentrating it to a receiving device (16) such as a photovoltaic cell or thermovoltaic cell, comprising a non-tracked waveguide concentrator (14) with integral light turning element (12). It is thus possible to provide a solar apparatus for generating power in a very cost effective manner compared to conventional solar apparatus such as photovoltaic modules.
摘要:
A liquid crystal display device comprises: a layer of a chiral liquid crystal material disposed between first and second substrates (1,1'); and means for applying a voltage (6,6',7) across the liquid crystal layer. A first region of the liquid crystal layer is an active region (10) for display and a second region of the liquid crystal layer is a nucleation region (11) for generating a desired liquid crystal state in the first region when a voltage is applied across the liquid crystal layer. The ratio of the thickness d of the liquid crystal layer to the pitch p of the liquid crystal material has a first value (d/p) A in the first region of the liquid crystal layer and has a second value (d/p) N different from the first value in the second region of the liquid crystal layer. The value (d/p) N of the ratio of the thickness d of the liquid crystal layer to the pitch p of the liquid crystal material in the second region of the liquid crystal layer is selected such that, when no voltage is applied across the liquid crystal layer, the liquid crystal state stable in the second region of the liquid crystal layer is topologically equivalent to the desired liquid crystal state under application of a voltage.