JPS58217955A - Automatic original conveyor - Google Patents

Abstract

PURPOSE:To prevent adsorption holes from being copied by providing a white plate which has bottomed grooves on the back surface of a transparent conveyor belt, and forming suction holes for applying negative pressure to the adsorption holes of the conveyor belt outside original copying areas at both ends of the grooves. CONSTITUTION:An original 12 fed one by one, by a feeding-in device are sucked to the coveyor belt 1 through the adsorption holes 2 because the negative pressure in a vacuum chamber 3 operates on the adsorption holes 2, 2... through the suction holes 4 through the bottomed grooves 6, and they are conveyed by a driving roll 8 until a specific position of platen glass 10 to be exposed. In this case, light from a light source projected to the conveyor belt 1, but the conveyor belt 1 is made of a transparent material, so the light is transmitted therein and reflected by the platen-side surface of the vacuum chamber 3, i.e. white plate 5. In this case, almost all of the light is reflected nearly uniformly and almost no shadow of the holes 2 are projected on a photoreceptor substantially.

Description

[Detailed description of the invention] The present invention relates to a suction type automatic document feeder for a copying machine.

When placing original documents on a copying machine on the platen, it is cumbersome to manually arrange each document one by one, so if you set many originals at once, the copying machine will do the rest. A feeding device feeds out the original one sheet at a time, and a conveyor belt having a large number of sheets discharges and conveys the remaining originals, aligning them to appropriate positions on the platen, and making the required number of copies. After doing so, eject the original 1. Automatic document feeders that transport the next document again are widely used. However, the conventional automatic document feeder normally uses a white conveyor belt, and as shown in FIGS. Since the mouth 4 is open, when copying originals with high light transmittance such as bookkeeper's manuscripts, or when copying at the same size,
When the copy area is smaller than the copy paper, such as when the original is υ smaller than the copy paper, there is a drawback that the suction holes of the document conveyance belt are projected as dots on the white background when the copy is made.

Furthermore, since the number of suction holes that suck the original document when it enters the conveyor belt and when it exits the conveyor belt is reduced, the conveyance force becomes smaller. To deal with this, raising the negative side increases the force with which the conveyor belt is attracted to the intake hole.
The runner-up was that the drive roll slipped due to friction between the vacuum box and the conveyor belt, which resulted in increased noise.

The present invention has been developed to eliminate the drawbacks of the conventional automatic document feeder, and is to provide a white plate having a bottomed groove on the back side of a transparent conveyor belt, and to By providing the suction holes for applying negative pressure to the suction holes of the conveyor belt outside the document copying area at both ends of the front 6nC groove, an automatic document conveying device is provided in which the suction holes are not substantially copied. The purpose is to

This invention will be described in detail below with reference to the drawings.

FIG. 4 is a side view of the suction type automatic document feeder in which the present invention can be implemented, FIG. 5 is a bottom view of the same, and FIG. 6 is an A-A in FIG.
Figure 7 is a cross-sectional view taken along line B-B' in Figure 5. The document transport belt 1 is made of a highly transparent polymer sheet, and has a large number of perforations 2, 2... ...is the installation. The mounting surface of the vacuum box 3 on the platen glass side,
That is, the plate 5 located on the back side of the document conveying belt 1 is constructed in white, and the plate 5 has holes corresponding to the positions of the suction holes 2.
A bottomed groove 6 with a semicircular cross section is provided, and intake holes 4 communicating with the inside of the vacuum box are provided at both ends of the groove 6 to apply negative pressure to the r/j and mounting holes 2 through the groove 6. However, the intake hole 4 is provided outside the original copy area T as shown in FIG. 84.

Then, the document conveyance belt 1 is wound around the drive 1h roll 8 that drives the document conveyance belt 1 and its idler V9, and the vacuum box is installed on the back side of the platen glass 10Kxl of the belt 1. l? 5- Exhaust the air in A box 3 by vacuum fan 11.

When the original 12 is fed one sheet at a time by a feed/shrinking device (not shown) in the document conveying device configured as described above, the negative pressure inside the vacuum box 3 is applied to the suction hole 4 and the bottomed groove 6. act on the suction holes 2.2° . The drive roll B
After the original is transported to an appropriate position on the platen glass 10 as shown in FIG. The shrine will be placed at the appropriate location. After the required number of copies are made at that position, the document is conveyed again by the document conveyance belt and discharged.

Document 1 placed at an appropriate position on the platen glass
2 receives light from a light source (not shown) below the platen glass, and generates static electricity on the photoreceptor (not shown).

Therefore, if the original is thin or the copy area of the original is smaller than the copy paper, the light source from the light source corresponds to the transport belt 1, but the transport belt 1 may be made of transparent material. Therefore, the light that hits the conveyor belt 1 passes through without being reflected almost as it is, and then hits the platen side surface of the vacuum box 3 behind it, that is, the white plate 5, and is reflected there. Become. However, the white [
Since there is only a bottomed groove 6 with a semicircular cross section as described above and no holes, almost all of the light hitting the white plate S is reflected almost uniformly. Therefore, the image of the hole 1 provided in the conveyor belt 1 is substantially projected onto the photoreceptor and lasts a long time.

Since the present invention is configured as described above, even if the original is thin or the copying area of the original is smaller than the copy paper, the shadow of the suction hole provided in the conveyor belt will remain on the photoreceptor. It has the advantage that high-quality copies can be obtained since it is rarely projected.

Therefore, intake holes 4 for transmitting the negative pressure of the vacuum box 3 to the bottomed groove 6 are opened at both ends of the front 1C bottomed groove 6. Since the air intake hole 4 is provided outside the original copying area as described above, it is also important that the air intake hole 4 appears on the copy.

Further, according to the present invention, when one end of the original 12 is fed into the conveyor belt, that is, when the original 11 is at the right end than in the state shown in FIG. Since negative pressure is directly applied from the suction hole through the hole, the suction force per unit area of the document is strongly applied, but only one end of the document receives the suction force. On the other hand, when the document is conveyed by the conveyor belt to the vicinity of the center of the platen glass, the entire document is subjected to negative pressure by the numerous suction holes, but the negative pressure is exerted through the bottomed groove 6. Since the vicinity of the air intake holes opened at both ends of the groove 6 is not strong against the air, the adhesion force applied per unit area of the document is weak.

For this reason, there is a secondary benefit in that the suction force exerted on the entire document is greatly reduced no matter where the document is placed during transportation.

Of course, it goes without saying that there is no reason why the present invention should be limited to the above embodiments. In other words, in the above embodiment, a vacuum box is provided behind the conveyor belt, and the food 5 on the platen glass side surface of the vacuum box is white, but as long as the white plate 5 is placed in the above position, There is no necessity to provide the vacuum box in the front position.

91, as shown in FIG. 8, only a white plate 5 with a bottomed groove is provided on the back side of the conveyor belt, and the negative pressure from the illustrated vacuum fan is applied to the intake hole 4 by the intake manifold 13. Well, you can let it happen. Further, the direction of the bottomed groove 6 provided in the white plate 5 is not necessarily limited to the direction shown in the drawings, and the groove may be provided in a direction extending perpendicularly to the original feeding direction.

[Brief explanation of the drawing]

Figure 1 is a side view of a conventional suction type automatic document feeder.
3 is a bottom view of FIG. 1, FIG. 3 is a cross-sectional view of FIG. Bottom view, Figure 6 is A in Figure 5
-A' line sectional view, Figure 7 is the same figure B-B' line sectional view,
FIG. 8 is a side view of a suction type automatic document feeder showing another embodiment. In the figure 1...Document transport belt 2...Suction hole
4. Intake hole 5.. White plate 6.. Bottom groove Applicant Fuji Xerox Co., Ltd.

Claims (1)

[Claims] In a device that uses negative pressure from the back side of a conveyor belt having a large number of suction ports to attract and convey documents to the conveyor belt,
The conveyor belt is made of a transparent sheet, and a white plate having a bottomed groove corresponding to the position of the suction hole is provided on the back side of the conveyor belt, and the negative is connected to the Ifi attachment hole through the groove. An automatic document feeder characterized in that air intake holes for applying pressure are provided outside the document copying area at both ends of the groove.