초록 ▼

An image scanner for reading images from an original document or the like less susceptible to induced noise. An image output signal from a CCD sensor is sampled and held and the black level of the resulting signal is adjusted to a desired value. The black-level-adjusted signal is converted to digita

An image scanner for reading images from an original document or the like less susceptible to induced noise. An image output signal from a CCD sensor is sampled and held and the black level of the resulting signal is adjusted to a desired value. The black-level-adjusted signal is converted to digital form and transmitted to an external utilization unit after its timing has been properly adjusted.

대표청구항 ▼

In an image scanner for reading images, an image reading unit adapted to output in synchronization with a predetermined clock signal an image signal corresponding to a quantity of light reflected from the surface of an original document, comprising: a light-detecting element for outputting an image

In an image scanner for reading images, an image reading unit adapted to output in synchronization with a predetermined clock signal an image signal corresponding to a quantity of light reflected from the surface of an original document, comprising: a light-detecting element for outputting an image signal; means for temporarily holding said image signal; level setting means for setting a black level to a desired value; arithmetic means for executing an arithmetic operation using said black level set by said level setting means to change the black level of said held image signal; signal converting means for converting said image signal into a digital signal which is used as said output image signal; and timing adjusting means for causing the control timing of said light-detecting element and signal converting means to be synchronous with the timing of said clock signal, said light-detecting element, temporary holding means, level setting means, arithmetic means, signal converting means, and timing adjusting means being provided in said unit.