Scanning method by using sheet feed scanner

#1. Field of the Invention

#The present invention relates to a scanning method by using a sheet feed scanner. More specifically, the present invention relates to a scanning method with improved resolution by using a sheet feed scanner.

#2. Description of the Related Art

#It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.

#The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principle of the invention. In the drawings,

#FIG. 1 is a schematic, cross-sectional view of a conventional sheet feed scanner;

#Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

#FIG. 2 is a schematic cross-sectional view of a sheet feed scanner according to one embodiment of the present invention. The sheet feed scanner 200 includes a sheet feeder 210 and a scan module 230. The sheet feed scanner 210 serves to convey a paper sheet 250. The scan module 230 scans the sheet paper 250 conveyed from the sheet feeder 210. The sheet feeder 210 includes a conveying guide 212, a plurality of rollers 214 and a scanning window 216. The sheet paper 250 is conveyed along the conveying guide 212. The rollers 214 are arranged on the conveying guide 212, with two of the rollers 214 rolling in contact with each other so that the paper sheet 250 can be transmitted by the pair of the rollers to pass between the two rollers 214 and go forward. When a motor (not shown) drives the rollers 214 to rotate, the rollers 214 convey the paper sheet 250 in a moving direction 220. An axis 215 of each of the rollers 214 is perpendicular to the moving direction 220 of the paper sheet 250. Furthermore, a scanning window 216 is arranged under the sheet feeder 210. The scanning module 230 includes a stationary scanning head 232, and a transmission mechanism 234. The transmission mechanism 234 drives the scanning head 232 back and forth to positions where it scans the paper sheet 250 conveyed by the sheet feeder 210, through the scanning window 216 of the sheet feeder 210. The transmission mechanism 234 consists of a gear set (not shown) and a stepping motor (not shown). The scanning head 232 goes forward step by step by the use of the gear set and the stepping motor of the transmission mechanism 234. The transmission mechanism 234 and the stepping motor are well known in the art and thus the detailed description thereof can be omitted.

#FIG. 3 is a schematic view illustrating the scanning operation of the sheet feed scanner according to one embodiment of the present invention. In the conventional scanner, a scanning resolution is obtained after the paper sheet is sent to the scanning region by the stepping motor and the rollers 214. However, with the aid of moving the scanning head 232 as illustrated in the present invention, the scanning resolution can be greatly enhanced. With reference to FIGS. 2 and 3, the paper sheet 250 is placed into the sheet feeder 210. By the control of the stepping motor and the rollers 214, the paper sheet 250 travels forward a first distance D in the moving direction, and then stops. After the paper sheet 250 stops, a scanning region 260 of the paper sheet 250 is exposed through the scanning window 216. In this embodiment, a center of the scanning head 232 is located at a first position 272 which faces the scanning region 260. After the paper sheet 250 stops, the scanning head 232 scans a corresponding portion of the paper sheet accessible from the first position 272, then the center of the scanning head 232 travels a second distance S from the first position 272 to a second position 274 in the first scanning direction 282. The first distance D is larger than the second distance S. After the scanning head 232 stops, the scanning head 232 scans a corresponding portion of paper sheet accessible from the second position 274. The scanning head 232 then travels a second distance S in the first scanning direction 282, and moves to a third position 276. After the scanning head 232 stops at the third position, the scanning head 232 scans a corresponding portion of the paper sheet 250 accessible from the third position 276. The scanning head 232 then travels a second distance S in the first scanning direction 282, and moves to a fourth position 278. Similarly, after the scanning head stops, the scanning head 232 scans a corresponding portion of the paper sheet 250 accessible from the fourth position 278. It should be noted that an area where the scanning head 232 scans from the first position 272 to the fourth position 278 is smaller than that of the scanning region 260. Furthermore, the scanning window 216 is designed such that a length of the scanning window 216 in the direction 220 of the paper sheet 250 is larger than or equal to the distance D.