JPH0445034A - Original conveyor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a document conveying device, and particularly to one used in an image reading device such as a facsimile machine that closely reads an image of a document.

[Conventional technology]

As a conventional document conveyance device of this type, there is one used in a conveyance system of a document reading device, such as the one shown in FIG. 6, for example. This conveyance system includes a front-stage first feed roller 100 with which a separation piece 101 for separating documents comes into contact, and a contact image sensor (hereinafter referred to as C8) as a document reading means.
102 . The document 104 is separated and fed one by one by the front conveyance roller 100, and is conveyed by the rear conveyance roller 103, while the information on the document 104 is sequentially read by the image sensor 102. This front conveyance roller 100
The and rear conveyance roller 103 are operated in conjunction with each other via a gear train by a reading drive motor (not shown). On the other hand, the timing at which the image sensor 102 reads the document 104 is determined based on a detection signal from a document edge sensor 107 provided between the front conveyance roller 100 and the rear conveyance roller 103.

Since the C8 (contact sensor) has a shallow depth of field,
If the document were to float away from C8, the quality of the read image would deteriorate, so as shown in FIG. 7, the conveyance roller was pressed against C8 while hitting the middle of the document to prevent the document from floating. Here, the conveyance roller is made of hard rubber and manufactured with highly precisely defined surface flatness.

[Problem that the invention is trying to solve]

However, the above conventional example had the following drawbacks.

(1) As mentioned above, the conveyance roller is made of hard rubber and is in pressure contact with C8 throughout the hit. Therefore, there is a uniform conveying force throughout the hit. Therefore, if the document is skewed for some reason and only one end of the document is caught before it is bitten by the conveyance roller, the load of the separation roller is on the upstream side, so There is a problem in that a force couple acts on both the left and right ends of the document, and as shown in FIG. 7, the skew of the document increases.

(2) As mentioned above, the conveyance roller needs to be in close contact with the C8 throughout the hit to prevent even the slightest lift of the document, but if there are depressions or protrusions on the surface of the C8 or the conveyance roller, the conveyance roller Since the C8 is separated, the surfaces of the C8 and the conveyance roller are manufactured with highly accurate flatness control, which leads to cost store bumps.

(3) If C3 is brought into close contact with C8 by strongly pressing against the conveying roller and slightly deforming the surface of the roller, the conveying force will increase. In other words, a motor with torque sufficient to withstand this load is required, but the size of the motor generally increases in proportion to the torque, leading to an increase in the size and cost of the device.

An object of the present invention is to reduce the torque of the drive system for conveying the document as described above and prevent skewing of the document, thereby stabilizing the document conveyance and making it easier to manufacture the conveyance roller.

[Means for Solving the Problems (and Effects)] According to the present invention, the conveyance roller is made of high-friction hard rubber only near the center of the document width, and the surfaces from the left and right to the ends are made of low-friction and soft rubber. By constructing each piece of foam sponge,
The conveying force near the center of the document width is increased, and the conveying force at the left and right edges is minimized (to prevent the increase in skewed feeding of the document, and the surface of the foamed sponge portion is slightly deformed to prevent the document from floating).

〔Example〕

The present invention will be explained below based on illustrated embodiments. 1 shows a document conveying device according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a frame constituting the outer frame of the apparatus, and within this frame 1 there is provided a conveyance path P through which a sheet-shaped original S is conveyed.

In the conveyance path P, a document receiving plate 2, a front conveyance roller 3 as a front conveyance means, a rear conveyance roller 4 as a rear conveyance means, and a document discharge guide plate 5 are arranged in this order from the A side in the conveyance direction.

The front conveyance roller 3 is arranged below the conveyance path P, and the document S
A separation plate 6 constituting document separation means is pressed above the separation plate 6 via a support plate 61 by a spring member (not shown).

On the other hand, the rear-stage conveyance roller 4 is arranged at a predetermined interval on the downstream side of the front-stage conveyance roller 3 in the conveyance direction. It is pressed by a leaf spring or the like.

As shown in FIG. 2, the reading means 7 includes a light receiving section 72 including a photoelectric conversion element provided on the top surface of a flat board 7, and a light source 73 such as a xenon tube arranged below the board 7. It is equipped with The light receiving section 72 is constructed by disposing a photoelectric conversion element 75 on a transparent plate 74 such as a glass plate, and covering the photoelectric conversion element 75 with a transparent thin plate 76 from above.

The photoelectric conversion element 75 is located at the contact portion of the rear conveyance roller 4 and sequentially reads the document S illuminated by the light source 73 through a through hole 77 provided in the substrate 71.

The operation of the above configuration will be explained.

The document S inserted into the conveyance path P is detected by the facsimile main body by the document detection sensor 10 that detects the presence or absence of the document, and the front conveyance roller 3 is moved clockwise and the rear conveyance roller 4 is moved clockwise.
rotate counterclockwise.

The document is conveyed downstream by the frictional force between the front conveyance roller 3 and the separation plate 6, and after the leading edge of the document hits the document edge detection sensor 11, it is further conveyed a predetermined distance and is sandwiched between the rear conveyance roller 4 and the reading means 71. , the image is read while being conveyed further downstream.

Thereafter, the reading operation ends when the trailing edge of the document passes the document edge detection sensor 11 and is conveyed a predetermined distance, and the document is discharged onto the document discharge guide plate 5.

Next, FIG. 3 shows a perspective view of the vicinity of the rear conveyance roller, which is a feature of the present invention.

Here, the latter conveyance roller 4 is integrally formed by adhesion or the like, of a hard roller 4a made of high-friction hard rubber and a foam roller 4b whose surface is made of low-friction, soft foam rubber on the outer periphery of a support shaft 4c. has been done.

Further, the roller portion of the rear conveyance roller 4 is connected to the front conveyance roller 3.
It has a symmetrical shape with the center distribution in the longitudinal direction, and is wider than the entire manuscript. The surface of the hard roller 4a is manufactured so that its flatness is controlled to be less than the depth of field of the reading means.

The outer diameter of the foaming roller 4b is set larger than that of the hard roller 4a. The width of the hard roller 4a is set to be somewhat wider than the width of the front conveyance roller 3.

The above configuration has the following effects.

(1) As shown in FIG.
If the document is skewed for some reason and only one edge of the document is bitten before the document 1 is bitten, the load F2 of the separating roller and the force of the rear transport roller 4 biting one edge of the document will be increased. F1 acts on the document s1 as a couple, but the foaming roller 4
Since b has low friction and is soft, the conveyance force F at one end of the roller is small, and the couple hardly acts on the document, so that the skew does not increase.

Further, when the document is conveyed downstream and becomes the document S2, the hard roller 4a bites the document and a high conveyance force F3 acts on the document. By the above-described operation, the document is stably conveyed without increasing skew.

(2) Next, the state in which a document is conveyed and read will be explained.

The flatness of the surface of the hard roller 4a is controlled in the vicinity of the center of the document, and the document is brought into close contact with the reading means 7 within the depth of field and can be read satisfactorily.

In the left and right ranges other than the center of the document, the outer diameter of the foam roller 4b is larger than that of the hard roller 4a, so the surface of the foam roller 4b is slightly deformed between it and the reading means 7, which prevents the original from floating and brings it into close contact with the reading means. , read well.

[Other Examples]

Other examples are shown below.

(1) In this example, as a general case, the outer diameter of the foaming roller was set larger than the diameter of the hard roller, but this ratio was determined by the flatness of the foaming roller, hard roller, and contact image sensor. The same effect can be obtained even if it is changed depending on convenience, the depth of field of the contact image sensor, etc.

(2) A similar effect can be obtained by integrally and thinly wrapping a low-friction rubber or plastic resin around the surface of the foam roller.

The cross section of the foamed roller part of the conveyance roller that carried out this process is shown in Figure 5.
As shown in the figure. Here, 4d is a pipe-shaped roller made of low-friction rubber or plastic resin, and is integrally formed with the foaming roller 4b by adhesion or the like. As a unique effect of this embodiment, in this embodiment, since the roller surface is foamed, when the inside of the document is small, minute holes in the foam may be read as black, resulting in image deterioration, and the possibility of rubbing against the document. Although there is a possibility that the surface of the foam may be scraped due to the foaming process, such a drawback is eliminated in this embodiment (2).

(3) In the above-mentioned embodiment, the image was read by a contact type image sensor, but a similar effect can be obtained by using a reduction optical system using a conventional COD, in which a glass plate is brought into contact with a conveying roller.

As explained above, the document is read by placing the conveyance roller in direct contact with the contact image sensor, and by configuring the central area of the conveyance roller with a hard rubber roller and the other left and right areas with foam sponge rollers, the following effects can be achieved. There is.

(1) Since the conveyance force at the left and right ends of the conveyance roller is small, even when the document separation means is located upstream of the conveyance, there is little couple force acting on the document, and the skew of the document does not increase, resulting in good reading.

(2) The flatness of the surface of the conveyance roller only needs to be controlled with high precision on the hard rubber roller part, and the flatness of the foamed sponge roller part can be controlled more roughly, making it easier to manufacture parts and improve yields, reducing costs. Go down. Furthermore, the flatness of the surface of a contact type image sensor is similarly roughly managed, resulting in a similar effect.

(3) There is no need to deform the transport roller or image sensor by applying strong pressure to bring the surface of the transport roller into close contact with the image sensor (this reduces the driving load, reduces the size of the motor, and costs You can down.

〔Effect of the invention〕

Since the document conveying device according to the present invention is as described above,
This has the effect that documents can be conveyed smoothly without skewing.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a document conveying device embodying the present invention, and FIG.
The figure is a sectional view illustrating the reading means of the document conveyance device embodying the present invention, FIG. 3 is a perspective view illustrating the conveyance roller, which is a feature of the present invention, and FIG. FIG. 5 is a plan view for explanation, FIG. 5 is a perspective view for explanation of the conveyance roller of another embodiment, and FIG.
FIG. 7 is a sectional view of a conventional document conveying device, and FIG. 7 is a plan view for explaining the skewed document feeding state of the conventional document conveying device. 3 is a front conveyance roller, 4 is a rear conveyance roller, 4a is a hard roller, 4b is a foaming roller, 4C is a support shaft, 6 is a separation plate,
7 is the reading means, S is the original

Claims (2)

[Claims] (1) In a document conveyance device that reads a document while conveying the document by directly contacting a conveyance roller with a contact image sensor, etc., the central portion of the conveyance roller is constructed of a high-friction hard rubber roller; A document conveying device characterized in that the range from the left and right edges to the outside of the document width is comprised of low-friction, soft foamed sponge rollers. (2) Claim 1, characterized in that the outer diameter of the foamed sponge roller is larger than the outer diameter of the hard rubber roller.
Document transport device.