Optical exposure system for color video printer with three groups of lines of liquid crystal elements, one group per color

An optical exposure system for exposing an image formed of pixels comprising:

• a liquid crystal display including a liquid crystal part and a color filter part where,
• said liquid crystal part has a first liquid crystal group, a second liquid crystal group and a third liquid crystal group, where each liquid crystal group includes a plurality of liquid crystal elements, each of said liquid crystal elements having a common scanning line input for turning on the liquid crystal element, and each of said liquid crystal elements having an independent video input for controlling the transmissivity of the liquid crystal element,
• said color filter part has red, green and blue filter portions for filtering light from said first liquid crystal group, said second liquid crystal group and said third liquid crystal group, respectively, each of said filter portions including a plurality of filter elements having different transmissivities, said plurality of filter elements aligned to receive light from said plurality of liquid crystal elements,
• light source means disposed to transmit light through the liquid crystal elements and the aligned filter elements of the liquid crystal display to form an image having, for each pixel, an intensity of red, green and blue light components proportional to the transmissivities of said first group, said second group and said third group of liquid crystal elements, respectively, and of said red, green and blue filter portions, respectively.

An optical exposure system for exposing an image formed of pixels comprising:

• a liquid crystal display including a liquid crystal part and a color filter part where,
• said liquid crystal part has a first liquid crystal group, a second liquid crystal group and a third liquid crystal group, where each liquid crystal group includes a plurality of liquid crystal elements, each of said liquid crystal elements having a common scanning line input for turning on the liquid crystal element, and each of said liquid crystal elements having video input for controlling the transmissivity of the liquid crystal element,
• said color filter pan has red, green and blue filter portions for filtering light from said first liquid crystal group, said second liquid crystal group and said third liquid crystal group, respectively, each of the red, green and blue color filter portions having "n" color Filter elements having transmissivity ratios 1/K.sup.0 :1/K.sup.1 :
• - - - :1/K.sup.n-1 wherein K is the number of gradations of each liquid crystal element and where K and "n" are integers, said plurality of filter elements aligned to receive light from said plurality of liquid crystal elements,
• light source means disposed to transmit light through the liquid crystal elements and the filter elements of the liquid crystal display to form an image having an intensity of red, green and blue components proportional to the transmissivities of said first group, said second group and said third group of liquid crystal elements, respectively and of said red, green and blue filter portions, respectively.