Patent ID: 7835092

Claim:
A system, comprising: a housing; a first scrolling assembly, formed of first and second rollers, and a first scroll material extending between said first and second rollers, said material having at least one clear portion, and at least first and second other color portions, said clear portion being between said first and second color portions, so that said first color portion is on one side of said clear portion and said second color portion is on the other side of said clear portion, where a saturation of color in each of said two other color portions varies along a length of said scroll material defining a gradient axis, and where said saturation of color changes along said gradient axis for each color portion, said rollers being rotatable relative to said housing, said scrolling assembly and said housing defining an area between said first and second rollers that forms an optical gate through which a light beam is passed, where movement of said first and second rollers changes a position of the first scroll material in said optical gate; a second scrolling assembly, formed of third and fourth rollers, and a second scroll material extending between said third and fourth rollers, said second scroll material having at least one clear portion, and at least first and second other color portions, said clear portion being between said first and second color portions, so that said first color portion is on one side of said clear portion and said second color portion is on the other side of said clear portion, where a saturation of color varies along a length along a gradient axis and where said saturation of color changes along said gradient axis, said rollers being rotatable relative to said housing to move a portion of said second scroll material which passes through said optical gate; and a roller moving part, coupled to said housing, and commonly rotating said first and second rollers in synchronism with one another, in order to move said first scroll material to change a position of the first scroll material in said optical gate, and commonly rotating said third and fourth rollers in order to move said second scroll material to change a position of said second scroll material in said optical gate, where both said scroll materials have continuously varying non-discontinuous saturation.