Display apparatus, method and light source

A display apparatus for projecting an image onto a projection object, the display apparatus comprising:

• a light source, said light source comprising at least one superluminescent light emitting diode,
• wherein the light source comprises a plurality of superluminescent light emitting diodes, said superluminescent light emitting diodes being operable to emit light having a center wavelength, the center wavelength of light emitted by at least two of said plurality of superluminescent light emitting diodes being different,
• the apparatus further comprising at least one light modulating device arranged in a beam path of a light beam emitted by said light source and operable to emit influenced light upon incidence of said light beam, the light modulating device being operatively connected to an electronic control, and
• the display apparatus further comprising a projection optics arranged in a beam path of said influenced light.

A light source for a display apparatus, the light source comprising:

• a first superluminescent light emitting diode comprising:
• a first semiconductor heterostructure forming a PN junction
• and a first waveguide defining an optical beam path,
• the heterostructure including a gain region and a contact for applying a voltage to the PN junction in the gain region, so as to produce light emission from the gain region and along the optical beam path,
• the first superluminescent light emitting diode having a first emission spectrum a central wavelength of which is in the visible part of the optical spectrum,
• the light source further comprising a second superluminescent light emitting diode comprising:
• a second semiconductor heterostructure forming a PN junction,
• and a second waveguide defining an optical beam path,
• the second heterostructure including a gain region and a contact for applying a voltage to the PN junction in the gain region, so as to produce light emission from the gain region and along the optical beam path,
• the second superluminescent light emitting diode having a second emission spectrum a central wavelength of which is in the visible part of the optical spectrum, and
• the second emission spectrum being different from the first emission spectrum.

A method of displaying an image, the method comprising the steps of:

• providing a semiconductor heterostructure with a waveguide;
• causing the semiconductor heterostructure to emit visible light and to amplify said visible light by stimulated emission, thereby creating a primary light beam in the waveguide;
• causing the light beam to be radiated away from the semiconductor heterostructure without any substantial light beam portions being fed back to the semiconductor heterostructure;
• modulating the light beam to yield a pre-image;
• imaging the pre-image onto a full area of the image;
• and
• comprising the additional step of generating, in a time-division multiplexing manner, a plurality of pre-images, wherein all pre-images are imaged onto the full area of the image thereby creating the image.