Abstract: A document reading device includes red, green, and blue photoelectric transducers; a reader that reads a color image of a document with the photoelectric transducers; and a converter that converts the read color image into a grayscale image. The converter determines the maximum tone value MAX(RGB) among the red, green, and blue tone values of the RGB signal (RGB) of the pixel of the red, green, and blue colors to be a grayscale value of the pixel.

Abstract: An illumination device includes a light guide member having a bar-like shape and a light source disposed so as to face an end surface of the light guide member. The illumination device guides light from the light source in the light guide member and emits the light from a light emission surface of the light guide member formed in a longitudinal direction of the light guide member. The light emission surface includes a first light diffusing portion that is formed in a first portion near the light source and that has a protruding/recessed shape, and a second light diffusing portion that is formed in a second portion adjacent to an end of the first light diffusing portion, the end being away from the light source. The second light diffusing portion has a protruding/recessed shape and has lower light diffusivity than the first light diffusing portion.

Abstract: An illumination device includes a light guide member having a bar-like shape and a light source disposed so as to face an end surface of the light guide member. The illumination device guides light from the light source in the light guide member and emits the light from a light emission surface of the light guide member formed in a longitudinal direction of the light guide member. The light emission surface includes a first light diffusing portion that is formed in a first portion near the light source and that has a protruding/recessed shape, and a second light diffusing portion that is formed in a second portion adjacent to an end of the first light diffusing portion, the end being away from the light source. The second light diffusing portion has a protruding/recessed shape and has lower light diffusivity than the first light diffusing portion.

Abstract: An illumination device includes a light guide member having a bar-like shape and a light source disposed so as to face an end surface of the light guide member. The illumination device guides light from the light source in the light guide member and emits the light from a light emission surface of the light guide member formed in a longitudinal direction of the light guide member. The light emission surface includes a first light diffusing portion that is formed in a first portion near the light source and that has a protruding/recessed shape, and a second light diffusing portion that is formed in a second portion adjacent to an end of the first light diffusing portion, the end being away from the light source. The second light diffusing portion has a protruding/recessed shape and has lower light diffusivity than the first light diffusing portion.

Abstract: An illumination device includes a light guide member having a bar-like shape and a light source disposed so as to face an end surface of the light guide member. The illumination device guides light from the light source in the light guide member and emits the light from a light emission surface of the light guide member formed in a longitudinal direction of the light guide member. The light emission surface includes a first light diffusing portion that is formed in a first portion near the light source and that has a protruding/recessed shape, and a second light diffusing portion that is formed in a second portion adjacent to an end of the first light diffusing portion, the end being away from the light source. The second light diffusing portion has a protruding/recessed shape and has lower light diffusivity than the first light diffusing portion.