Abstract: An optical lens device of image scanner includes a diaphragm and plural lenses. The plural lenses, diaphragm, and image induction element are linearly arranged for defining an optical path between the document and the image induction element. Wherein, among the plural lenses, the one that is most close to the manuscript is called the first lens, and the other one that is most close to the image induction element is called the last lens, and the distance between the last lens and the image induction element is called BFL, and the length of the image induction element is called image height, and the total optical length between the document and the image induction element is called TT, and the effective focus length of the optical lens device is called EFL. If the optical lens device fulfills following conditions: the diameter of the last lens/the diameter of the first lens>1; EFL/image height<0.9; and BFL/TT<0.

Abstract: A LED light source used in a scanner is disclosed, and particularly a series of lenses employed to condense the LED light on the front and rear sides and disperse the LED light to the left and right sides. LED compared with CCFL employed as a light source can improve the problem of high power consumption, warm-up, and the limits of lifetime. Furthermore, the light through the lens extends the range of the left and right sides on a scanned material. Therefore, the amount of the LEDs decreases, than that skilled in the art used a large number of LEDs for obtaining a smoother field of light, and achieve low power consumption.

Abstract: An optical lens device of image scanner includes a diaphragm and plural lenses. The plural lenses, diaphragm, and image induction element are linearly arranged for defining an optical path between the document and the image induction element. Wherein, among the plural lenses, the one that is most close to the manuscript is called the first lens, and the other one that is most close to the image induction element is called the last lens, and the distance between the last lens and the image induction element is called BFL, and the length of the image induction element is called image height, and the total optical length between the document and the image induction element is called TT, and the effective focus length of the optical lens device is called EFL. If the optical lens device fulfills following conditions: the diameter of the last lens/the diameter of the first lens>1; EFL/image height<0.9; and BFL/TT<0.