Backlighting apparatus employing an array of microprisms

A backlight assembly for use in a flat panel electronic display, said display having a modulating means capable of providing an image to a remotely positioned observer, and said backlight assembly comprising:

• (a) a light generating means for generating a source of light rays;
• (b) a light transmitting means substantially related in surface area with said modulating means and having a light accepting surface adjacently positioned next to said light generating means, wherein said light transmitting means transports the light rays emanating from said light generating means via substantially total internal reflection in a direction substantially parallel to the viewing plane of said modulating means;
• (c) an array of microprisms disposed between said light transmitting means and said modulating means and each microprism having a light input surface optically coupled to said light transmitting means and a light output surface distal from and parallel to said light input surface and at least one sidewall tilted at an angle from between about 25 degrees to about 40 degrees from the direction normal to the surface of said light transmitting means and positioned for effecting total reflection of said light rays received by said input surface;
• wherein, said light rays reflecting through said light transmitting means enter said microprisms through said light input surfaces and emerge through said light output surfaces in a direction substantially perpendicular to said modulating means;
• and
• (d) an array of microlenses disposed in close proximity between said array of microprisms and said modulating means, wherein said output of each microprism is directed to a corresponding microlens and said light transmitted through said microlenses emerges as a substantially more collimated light source for said modulating means.

A backlight assembly for use in a flat panel electronic display, said display having a modulating means capable of providing an image to a remotely positioned observer, and said backlight assembly comprising:

• (a) a light generating means for generating a first and second source of light rays;
• (b) a transparent light transmitting means substantially related in surface area with said modulating means and having two light accepting surfaces, each adjacently positioned next to one of said light sources, wherein said light transmitting means transports the light rays emanating from said light generating means via substantially total internal reflection in a direction substantially parallel to the viewing plane of said modulating means;
• (c) an array of microprisms disposed between said light transmitting means and said modulating means and each microprism having a light input surface optically coupled to said light transmitting means and a light output surface distal from and parallel to said light input surface and a first and second sidewall tilted at an angle from between about 25 degrees to about 40 degrees from the direction normal to the surface of said light transmitting means and positioned for effecting total reflection of said light rays received by said input surface, wherein said light output surface area is greater than the area of said light input surface;
• wherein, said light rays reflecting through said light transmitting means enter said microprisms through said light input surfaces and emerge through said light output surfaces in a direction substantially perpendicular to said modulating means;
• and
• (d) an array of microlenses disposed in close proximity between said array of microprisms and said modulating means, wherein said output of each microprism is directed to a corresponding microlens and said light transmitted through said microlenses emerges as a substantially more collimated light source for said modulating means.

A backlight assembly for use in a flat panel electronic display, said display having a modulating means capable of providing an image to a remotely positioned observer, and said backlight assembly comprising:

• (a) a light generating means for generating a first, second, third and fourth source of light rays;
• (b) a light transmitting means substantially related in surface area with said modulating means having four light accepting surfaces, each adjacently positioned next to one of said light generating means, wherein said light transmitting means transports the light rays emanating from said light generating means via substantially total internal reflection in a direction substantially parallel to the viewing plane of said modulating means;
• (c) an array of microprisms disposed between said light transmitting means and said modulating means and each microprism having a light input surface optically coupled to said light transmitting means and a light output surface distal from and parallel to said light input surface and a first, second, third and fourth sidewall tilted at an angle from between about 25 degrees to about 40 degrees from the direction normal to the surface of said light transmitting means and positioned for effecting total reflection of said light rays received by said input surface wherein said light output surface area is greater than the area of said light input surface;
• wherein, said light rays reflecting through said light transmitting means enter said microprisms through said light input surfaces and emerge through said light output surfaces in a direction substantially perpendicular to said modulating means;
• and
• (d) an array of microlenses disposed in close proximity between said array of microprisms and said modulating means, wherein said output of each microprism is directed to a corresponding microlens and said light transmitted through said microlenses emerges as a substantially more collimated light source for said modulating means.

A direct-view flat panel display comprising:

• (a) a light generating means for generating light rays;
• (b) a modulating means for modulating light from said light generating means to form an image visible to a remote observer;
• (c) an image display means for displaying said image from said modulating means positioned adjacent to the light output surface of said modulating means, said display means comprising an array of tapered optical waveguides, the tapered end of each of said waveguides extending outward from said modulating means and having a light input surface optically coupled to said modulating means and a light output surface distal from said light input surface;
• (d) a backlight assembly comprising:
• (i) a light transmitting means substantially related in surface area with said modulating means and having a light accepting surface positioned adjacent to said light generating means, wherein said light transmitting means transports the light rays emanating from said light generating means via substantially total internal reflection in a direction substantially parallel to the viewing plane of said modulating means;
• (ii) reflecting means for collimating said light rays, said reflecting means disposed between said light transmitting means and said modulating means, said reflecting means comprising an array of microprisms with each microprism having a light input surface optically coupled to said light transmitting means and a light output surface distal from and parallel to said light input surface and at least one sidewall positioned for effecting total reflection of said light rays received by said input surface;
• wherein, said light rays reflecting through said light transmitting means enter said microprisms through said light input surfaces and exit through said light output surfaces in a direction substantially perpendicular to said modulating means.