JPH05316289A - Guide board on the front of optical scanner - Google Patents

Abstract

PURPOSE:To reduce the amount of dust attached by holding down the surface of sheet paper put on a belt in the vicinity of light irradiation parts and providing a saw-tooth notched section. CONSTITUTION:A guide board 9 clamps paper sheet 8, which is carried in the direction shown by an arrow 11 and is clamped between a belt 1, 2, with the belt 1. The scanner guide board 9 has a saw-tooth notched section at the edge to be irradiated which reduces the amount of dust to be attached on the edge section. With a plurarity of notched sections at the edge part, the linear portion adjacent to the scanning position of the edge is shortened and the length spreading the dust along the edge is also shortened. The dust spread from the guide board 9 to the arrow 11 can be removed before shielding a light receiving section 7 and the scanning position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guide plate in front of an optical scanner, and more particularly to improvement of the shape of the guide plate in front of an optical scanner in a sheet processing apparatus.

[0002]

2. Description of the Related Art In a conventional optical scanner, as shown in FIG. 3, a paper sheet 8 is conveyed on one side while being sandwiched between a belt 1 and a guide plate 19, and at the scanning position 10, the paper sheet 8 is conveyed. In order to keep the distance between the light receiving part 7 and the light receiving part 7 constant, it is desirable to bring the guide plate 19 as close as possible to the scanning position, and in order to secure a sufficient amount of light emitted from the light source part 6 to the scanning position 10, in FIG. As shown, the guide plate 19 on the light source section 6 side
The edges are cut into an edge shape.

[0003]

As described above, in the conventional guide plate 19 on the front surface of the optical scanner, the edge side of the light source section 6 side is linear, and therefore, the edge side of the paper sheet 8 during the conveyance thereof. As shown in FIG. 4, the guide plate 1
It can be confirmed experimentally that the dust 13 adhering along the edge of 9 grows. Further, as shown in FIG. 4, it can be confirmed that the dust 13 not only spreads along the edge but also grows in the direction perpendicular to the edge.

Since the edge of the guide plate in front of the optical scanner is close to the scanning position 10, as the amount of dust adhering to the edge increases as described above, the dust blocks between the scanning position 10 and the light receiving unit 7. Thus, there is a drawback that noise added to the image signal output from the light receiving unit 7 increases.

[0005]

A guide plate of an optical scanner according to the present invention is a guide plate of a guide plate for pressing and guiding the surface of a paper sheet held and conveyed on a belt in the vicinity of the light irradiation place. Saw-tooth cutouts are provided on the side edges.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a top view and a plan view of an embodiment of the present invention. The guide plate 9 of this embodiment is the conventional guide plate 1.
Similar to 9, the paper sheet 8 that is sandwiched between the belt 1 and the belt 2 and conveyed in the direction of the arrow 11 in FIG. 3 is sandwiched between the belt 1. The light emitted from the light source unit 6 illuminates the surface of the paper sheet 8 at the scanning position 10, and the reflected light is received by the light receiving unit 7.

In this embodiment, the guide plate 9 of the scanner
As shown in FIG. 1 (a), a saw-tooth cutout is provided on the edge side in order to reduce the amount of dust adhering to the edge side on the irradiation side. As shown in FIG. 1A, the shape of the cutout portion is trapezoidal so as not to interfere with the normal conveyance of the paper sheet 8. In addition, the upper surface of the serrated portion of the guide plate 9 is tapered downward toward the tip so that the amount of light emitted from the light source unit 6 to the scanning position 10 does not decrease and is tapered.

In the present embodiment, the guide plate 9 has a plurality of cutouts at the edges as shown in FIG. 1 (a) to shorten the straight line portion of the edge of each serrated portion in contact with the scanning position 10. Therefore, the length of the dust 13 spreading along the edge becomes short, so that the dust 13 adhering from the edge of the guide plate 9 toward the arrow 11 is at the scanning position 1
It falls before blocking between 0 and the light receiving part 7. That is, the amount of dust 13 attached can be reduced as compared with the conventional case.

In the present embodiment, the sawtooth-shaped notch is provided on the edge portion of the guide plate 9, but instead, a semicircular notch as shown in FIG. 5 or a triangular notch as shown in FIG. Obviously, the same effect as the present embodiment can be obtained.

[0011]

As described above, according to the present invention, the amount of dust adhering to the tip end portion of the guide plate can be reduced as compared with the prior art by providing the notch of an appropriate shape at the tip end portion of the guide plate. You can

[Brief description of drawings]

FIG. 1 is a top view and a side view of an embodiment of the present invention.

2A and 2B are a top view and a side view of a conventional guide plate.

FIG. 3 is a side sectional view of a scanner that uses a guide plate according to the related art and the present invention.

FIG. 4 is a top view showing a dust growing process using a conventional guide plate.

5A and 5B are a top view and a side view of an embodiment of the present invention.

6 (a) and 6 (b) are a top view and a side view of an embodiment of the present invention.

[Explanation of symbols]

 1 to 3 belts 4,5 rollers 6 light source section 7 light receiving section 8 paper sheets 9,19 guide plate 10 scanning position 12 optical scanner 13 dust

Front page continuation (72) Inventor Kuto, 1-1 1-1 Shinurashima-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Kanagawa Electric Robot Engineering Co., Ltd. Address 25 NEC Robot Engineering Co., Ltd.

Claims (1)

[Claims] 1. A sawtooth cutout is provided at an end portion of a guide plate for pressing and guiding the surface of a paper sheet held and conveyed on a belt in the vicinity of a light irradiation point, on the side of the light irradiation point. A guide plate in front of the optical scanner, which is characterized in that