Backlighting assembly utilizing microprisms and especially suitable for use with a liquid crystal display

An assembly for backlighting a liquid crystal display, comprising:

• (a) a backlighting light pipe having opposing top and bottom surfaces and opposing sides and extending lengthwise between opposite ends, said light pipe being divided into a series of longitudinally extending laterally adjacent light pipe sections which extend from one end of the light pipe to its other end and which are optically isolated from one another along substantially their entire lengths, whereby the individual light pipe sections act substantially independently with respect to one another on incoming light;
• (b) means for directing light into said light pipe and for causing it to move from one end of the light pipe towards the opposite end thereof;
• and
• (c) an arrangement of microprisms extending normal to the lengthwise axis of the light pipe from one side of said light pipe to its opposing side along the entire extent of said serving as the bottom surface of the light pipe for reflecting light within said light pipe upwards through its top surface in a generally collimated manner.

An assembly for backlighting a liquid crystal display, comprising:

• (a) a backlighting light pipe having opposing top and bottom surfaces and opposing sides and extending lengthwise between opposite ends;
• (b) an arrangement of microprisms extending normal to the lengthwise axis of the light pipe from one side of said light pipe to its opposing side along the entire extent of and serving as the bottom surface of the light pipe for reflecting light within said light pipe upwards through its top surface in a generally collimated manner;
• and
• (c) means for directing light into said light pipe from at least one end thereof and for causing it to move from one end of the light pipe towards the opposite end thereof, said means for directing light into said light pipe including means for limiting the maximum angle at which light enters the light pipe in relation to the lengthwise axis of the light pipe to an angle no greater than a predetermined angle, said microprisms being configured such that the light entering said light pipe is reflected off the microprisms towards the top surface of the light pipe at angles no greater than one-half said maximum angle with respect to lines normal to said top surface.

An assembly for backlighting a liquid crystal display, comprising:

• (a) a backlighting light pipe having opposing top and bottom surfaces and opposing sides and extending lengthwise between opposite ends;
• (b) an arrangement of microprisms extending normal to the lengthwise axis of the light pipe from one side of said light pipe to its opposing side along the entire extent of and serving as the bottom surface of the light pipe for reflecting light within said light pipe upwards through its top surface in a generally collimated manner;
• and
• (c) means for directing light into said light pipe from at least one end thereof and for causing it to move from one end of the light pipe towards the opposite end thereof, said means for directing light into said light pipe including light control means for limiting the maximum angle at which light enters the light pipe in relation to the lengthwise axis of the light pipe.

An assembly for providing backlighting comprising:

• (a) a backlighting light pipe having opposing top and bottom surfaces and opposing sides and extending lengthwise between opposite ends;
• (b) means for directing light into said light pipe and for causing it to move from one end of the light pipe towards the opposite end thereof;
• and
• (c) an arrangement of immediately adjacent microprisms extending normal to the lengthwise axis of the light pipe from one side of said light pipe to its opposing side along the entire extent of and serving as the bottom surface of the light pipe, each of said microprisms having a triangular cross-section extending downward to a point so as to define from said point opposing, upwardly angled light reflecting surface segments for reflecting light within said light pipe upwards through its top surface in a generally collimated manner.

An assembly for providing backlighting comprising:

• (a) a backlighting light pipe having opposing top and bottom surfaces and opposing sides and extending lengthwise between opposite ends, said light pipe being divided into a series of longitudinally extending laterally adjacent light pipe sections which extend from one end of the light pipe to its other end and which are optically isolated from one another along substantially their entire lengths, whereby the individual light pipe sections act substantially independently with respect to one another on incoming light;
• (b) means for directing light into said light pipe and for causing it to move from one end of the light pipe towards the opposite end thereof;
• and
• (c) an arrangement of microprisms extending normal to the lengthwise axis of the light pipe from one side of said light pipe to its opposing side along the entire extent of said serving as the bottom surface of the light pipe for reflecting light within said light pipe upwards through its top surface in a generally collimated manner.

A liquid crystal display assembly, comprising:

• (a) a backlighting light pipe having opposing top and bottom surfaces and opposing sides and extending lengthwise between opposite ends;
• (b) means for directing unpolarized light into said light pipe and for causing it to move from one end of the light pipe towards the opposite end thereof;
• (c) an arrangement of immediately adjacent microprisms serving as the bottom surface of the light pipe for reflecting light within said light pipe upwards through its top surface in a generally collimated manner;
• (d) means for linearly polarizing in a given polarity direction the light directed out of said light pipe through the top surface thereof, said polarizing means including a polarization arrangement which cooperates with said arrangement of microprisms such that substantially all of the light directed out of said light pipe through the top surface thereof is linearly polarized in said given polarity direction, said polarizing means including a retroreflecting sheet polarizer containing a series of longitudinally extending, adjacent parallel microprisms, said retroreflecting sheet polarizer being positionable in parallel relationship with and in front of the top surface of said light pipe such that said microprisms extend in directions transverse but not perpendicular to the microprisms of said light pipe.