A one-dimensional image sensor has N number of photosensitive element arrays arranged parallel to the fast scanning direction, N being a positive integer greater than 1. The adjacent N number photosensitive element arrays are separated from one another by a distance equal to the width of D number arrays in the slow scanning direction. If the moving speed of the one-dimensional image sensor in the slow scanning direction is set to M times as high as an ordinary speed, the distance between the adjacent N number photosensitive element arrays expressed in terms of the width of the D number arrays satisfies the following equation: D=Ma/n where a.noteq.nN, n being a positive integer equal to or smaller than N.
The invention provides a signal charge-coupled device (CCD) sensing apparatus, including at least one first CCD shift register, one first photo sensor set, and one second photo sensor set. The first CCD shift register includes a plurality of first CCD components and a plurality of second CCD components. The first photo sensor set includes multiple first photo sensors for receiving a first light signal and generating multiple first corresponding charge signals. The first charge signals can be received by the first CCD components. On the other hand, the second photo sensor set includes multiple second photo sensors for receiving a second light signal and generating multiple second corresponding charge signals. The second charge signals can be received by the second CCD components. The CCD sensing apparatus can acquire higher scanned image quality under high resolution.
In S1, an image reading device obtains an image region length Ld of an original placed on an original mounting portion, a set moving velocity Vm of an image reading unit, a required deceleration distance Ls, a reference velocity Vr, and an absolute length Z. In S5, the image reading device sets a flag to 0 if Vm.ltoreq.Vr (S2: NO) or Z.gtoreq.(Ld+Ls) (S3: YES) and reads the entire image region length while the image reading unit is moving at the set moving velocity Vm. The image reading device sets the flag to 1 if Vm>Vr (S2: YES) and Z<(Ld+Ls) (S3: NO), reads the image region while the image reading unit is moving at the set moving velocity Vm up to the deceleration start position while the distance moved by the image reading unit is less than or equal to (L1+Z-LS) (S17: NO), then if the distance is greater than (L1+Z-Ls) (S17: YES), the image reading unit performs deceleration reading and reads up to a position immediately downstream of the image region.
