Apparatus and method for generating wide-angle coherent light and display apparatus using wide-angle coherent light

A coherent light generation apparatus, comprising:

• a backlight unit to generate parallel light;
• and
• a coherent light generator to focus the parallel light from a pixel onto a focal point, and to generate coherent light so that a hologram is formed based on interference of light propagated from the focal point,
• wherein the light propagated from the focal point has a wide angle of at least 15°,
• wherein no slit is included in the coherent light generation apparatus, and
• wherein f=2/p cot(θ/2), where f denotes a focal point, p denotes a width of a pixel, and θ denotes a spatial angle of coherent light propagated from a focal point.

A coherent light generation method, comprising:

• generating parallel light passing through a pixel;
• and
• focusing parallel light output from the pixel onto a focal point to convert the parallel light output from the pixel into coherent light so that a hologram is formed based on interference of light propagated from the focal point,
• wherein the light propagated from the focal point comprises a wide angle of at least 15°, and
• wherein f=2/p cot(θ/2), where f denotes a focal point, p denotes a width of a pixel, and θ denotes a spatial angle of coherent light propagated from a focal point.

A display apparatus using a coherent light, the display apparatus comprising:

• a backlight unit to generate parallel light;
• a spatial light modulator to modulate a phase or an amplitude of the parallel light passing through a plurality of pixels, the spatial light modulator comprising the plurality of pixels;
• a coherent light generator to respectively focus parallel light output from the plurality of pixels, having the modulated phase or the modulated amplitude, onto corresponding focal points, to generate coherent light for each of the plurality of pixels;
• and
• a display unit to display a three-dimensional (3D) image in a space, based on interference of the coherent light generated for each of the plurality of pixels,
• wherein light propagated from the focal point comprises a wide angle of at least 15°, and
• wherein f=2/p cot(θ/2), where f denotes a focal point, p denotes a width of a pixel, and θ denotes a spatial angle of coherent light propagated from a focal point.

A coherent light generating apparatus comprising:

• a pixel disposed on a planar surface;
• a backlight unit to generate coherent and collimated light of a single wavelength that is parallel to the planar surface on which the pixel is disposed;
• and
• a coherent light generator to focus parallel light output from the pixel onto a focal point to convert the parallel light output from the pixel into coherent light,
• wherein the pixel is disposed between the backlight unit and the coherent light generator,
• wherein no slit is included in the coherent light generation apparatus,
• wherein the coherent light generator is disposed at a side of the planar surface to correspond to the pixel, and
• wherein f=2/p cot(θ/2), where f denotes a focal point, p denotes a width of a pixel, and θ denotes a spatial angle of coherent light propagated from a focal point.

A display apparatus comprising:

• a plurality of pixels disposed in a grid-like pattern on a planar surface;
• a backlight unit to generate coherent and collimated light of a single wavelength that is parallel to the planar surface on which the pixels are disposed;
• a plurality of coherent light generators to respectively focus parallel light output from the plurality of pixels onto focal points to respectively generate coherent light, wherein the plurality of pixels are disposed between the backlight unit and the plurality of coherent light generators, and each of the coherent light generators is positioned at a side of the planar surface to correspond to one of the plurality of pixels;
• and
• a display unit to display a three-dimensional (3D) image based on interference of the coherent light respectively generated for each of the plurality of pixels,
• wherein no slit is included in the coherent light generation apparatus, and
• wherein f=2/p cot(θ/2), where f denotes a focal point, p denotes a width of a pixel, and θ denotes a spatial angle of coherent light propagated from a focal point.

A coherent light generation apparatus, comprising:

• one or more light sources to provide parallel light;
• and
• a coherent light generator to respectively focus the parallel light from a pixel onto plural focal points to generate respective coherent light so that a hologram is formed based on interference of light propagated from the focal points,
• wherein the coherent light generation apparatus generates the respective coherent light independent of any diffracting of the parallel light imparted by light modulation of the parallel light before incident on the coherent light generator,
• wherein the pixel is disposed between the one or more light sources and the coherent light generator,
• wherein no slit is included in the coherent light generation apparatus,
• wherein the coherent light generator generates the coherent light at a wide angle of at least 15°, and
• wherein f=2/p cot(θ/2), where f denotes a focal point, p denotes a width of a pixel, and θ denotes a spatial angle of coherent light propagated from a focal point.

A coherent light generation apparatus, comprising:

• one or more light sources to provide parallel light;
• plural pixels;
• and
• a coherent light generator to respectively focus the parallel light, incident from each of the pixels or toward each of the pixels, onto different focal points and to convert incident light into respective coherent light so that a hologram is formed based on interference of light propagated from the focal points,
• wherein the pixels are disposed between the one or more light sources and the coherent light generator,
• wherein no slit is included in the coherent light generation apparatus,
• wherein the coherent light generator generates the coherent light at a wide angle of at least 15°, and
• wherein f=2/p cot(θ/2), where f denotes a focal point, p denotes a width of a pixel, and θ denotes a spatial angle of coherent light propagated from a focal point.