Camera flash, a camera, and a method of generating a flash
First Claim
1. A camera flash for a camera, the camera flash comprising:
- a lightguide arranged to extract light at least through one surface;
one or more light sources arranged, in use, to emit light into the lightguide, and three or more optical films;
wherein the or each light source is an LED or a laser diode;
wherein the flash is connectable in use to drive circuitry, the drive circuitry being for driving the light source(s) to emit a pulse of light,wherein the lightguide is a planar lightguide having two opposed major surfaces and at least one minor surface, the lightguide being arranged to extract light at least through one major surface,wherein each of the three or more optical films is provided over a major surface of the lightguide,wherein light extraction features for extracting light from the lightguide are arranged on at least one major surface of the lightguide, wherein the number density of the extraction features vary so as to be greater further away from the light sources so that there is more extraction further away from the light sources, andwherein an angular range of light emitted by the camera flash is substantially equal to a field of view of the camera.
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Accused Products
Abstract
A camera flash comprises a light guide arranged to extract light at least through one surface; and one or more light sources 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) 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 minimizing 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 of a mobile telephone camera.
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Citations
22 Claims
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1. A camera flash for a camera, the camera flash comprising:
- a lightguide arranged to extract light at least through one surface;
one or more light sources arranged, in use, to emit light into the lightguide, and three or more optical films;wherein the or each light source is an LED or a laser diode; wherein the flash is connectable in use to drive circuitry, the drive circuitry being for driving the light source(s) to emit a pulse of light, wherein the lightguide is a planar lightguide having two opposed major surfaces and at least one minor surface, the lightguide being arranged to extract light at least through one major surface, wherein each of the three or more optical films is provided over a major surface of the lightguide, wherein light extraction features for extracting light from the lightguide are arranged on at least one major surface of the lightguide, wherein the number density of the extraction features vary so as to be greater further away from the light sources so that there is more extraction further away from the light sources, and wherein an angular range of light emitted by the camera flash is substantially equal to a field of view of the camera. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
- a lightguide arranged to extract light at least through one surface;
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22. A method of generating a flash for flash photography, the method comprising driving light source(s) of a camera flash of a camera to emit a pulse of light, the camera flash further comprising:
- a lightguide arranged to extract light through one surface, the light source(s) being arranged, in use, to emit light into the lightguide; and
three or more optical films;wherein the or each light source is an LED or a laser diode, wherein the lightguide is a planar lightguide having two opposed major surfaces and at least one minor surface, the lightguide being arranged to extract light at least through one major surface, wherein each of the three or more optical films is provided over a major surface of the lightguide, and wherein light extraction features for extracting light from the lightguide are arranged on at least one major surface of the lightguide, wherein the number density of the extraction features vary so as to be greater further away from the light sources so that there is more extraction further away from the light sources wherein an angular range of light emitted by the camera flash is substantially equal to a field of view of the camera.
- a lightguide arranged to extract light through one surface, the light source(s) being arranged, in use, to emit light into the lightguide; and
Specification