JPH0580614A - Document reader - Google Patents

Abstract

PURPOSE:To carry a document in a state where its optical reading is assured with a light load and to easily form a document path. CONSTITUTION:In the document reader where the document path 29 is formed by document guides 27 and 28 faced to each other and a document reading part 32 provided with a document carrying roll 31 and a contact glass 34 and a document ejection roll 33 are sequentially placed along the document path 29, an elastic body 35 which is a bent thin plate member brought into a pressurized contact with its elasticity with the contact glass 34 of the document reader 32 is fixed and placed to the document guide 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeding type document reading device used in a facsimile machine, a copying machine or the like.

[0002]

2. Description of the Related Art Conventionally, a document feeding type document reading device has a structure shown in FIG. 3 or 4, for example.

First, in the structure shown in FIG. 3, a document passage 3 having a predetermined gap is formed by flat plate-like document guides 1 and 2 facing each other, and a document 4 is placed along the document passage 3. A pair of document conveying rollers 5 for conveying, a document reading portion 6, and a document discharge roller 7 are sequentially arranged. And
The document reading unit 6 includes a contact glass 8 fixed to the document guide 2 below and a white reference tape 9 provided on the lower surface of the document guide 1 above to face the contact glass 8. On the upstream side of the white reference tape 9, the leading edge of the original 4 being conveyed is the white reference tape 9
A protrusion 11 having an inclined surface 10 is formed so as not to ride on the vehicle. Then, below the contact glass 8, a light source 12, a mirror 13 and a lens 14 are provided.
A reading optical system 16 including a charge-coupled device 15 (hereinafter, referred to as CCD) is provided, and a reduction optical system image sensor is configured.

In such a structure, before the original 4 reaches the original reading section 6, the white reference tape 9 is irradiated with the light from the light source 12 to set the optical reading reference. Then, the document conveying roller 5 and the document discharging roller 7 rotate at the same peripheral speed, and conveys the document 4 in the document passage 3 at a uniform feeding speed. The image of the original 4 is read by the reading optical system 16.

Next, FIG. 4 shows another conventional example. That is, a document passage 19 is formed by the document guides 17 and 18 facing each other, and a contact glass 20 is provided on the document guide 18 below. And
An opening 21 is formed in the upper document guide 17, and a white roller 22 also serving as a conveying roller is provided at the position of the opening 21. The white roller 22 is pressed against the contact glass 20. Next, below the contact glass 20, a contact image sensor 25 including a light source 23 and a CCD 24 is provided.

In this case, the document 26 is conveyed while being pressed against the contact glass 20 by the white roller 22, and the image of the document is sequentially read by the contact image sensor 25.

[0007]

In the conventional example shown in FIG. 3, the document guides 1 and 2 forming the document passage 3 are often made of plastics, and the space between the document passages 3 is formed by molding distortion. There are large variations. Therefore, the position of the conveyed document 4 changes in the document passage 3,
It is easy for the image to be out of focus beyond the focus range of the reading optical system 16 or for the image to be distorted. Also, the document passage 3
There is also a problem that part of the document becomes narrow and the document 4 is caught.

Next, in the apparatus shown in FIG. 4, since the original document 26 is in close contact with the contact glass 20, the interval of the original document passage 19 can be set with a margin. The load increases,
There is the problem that the drive motor must be large.

[0009]

A document passage is formed by document guides opposed to each other, and a document reading unit having a document conveying roller and a contact glass and a document discharge roller are sequentially arranged along the document passage. In the document reading apparatus, a thin plate member is bent, and an elastic body that is pressed against the contact glass of the document reading unit by its elastic force is fixedly arranged on the document guide.

[0010]

In order to convey the original, since the original conveying roller and the original discharge roller are provided, the elastic force of the elastic body for pressing the original against the contact glass may be weak, which allows the original to be conveyed. Since the resistance is small and the drive motor can be small, and the original is in close contact with the contact glass, the original passage can be roughly formed. It is possible to perform stable reading without deviating the focal position of.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. First, flat plate-shaped document guides 27 and 28 facing each other form a document passage 29 having a predetermined gap, and a pair of document conveyance rollers 31 for conveying a document 30 along the document passage 29 and a document reading unit. 32 and a document discharge roller 33 are sequentially arranged. The document reading section 32 includes a contact glass 34 fixed to the lower document guide 28 and an elastic body 35 disposed on the lower surface of the upper document guide 27 so as to face the contact glass 34. ..

The elastic body 35 is made of a polyester thin plate member whose surface is formed in white so as to serve as a white reference at the time of reading, and the thin plate member is bent so that the lower surface of the upper original guide 27 is provided. Fixed surface 3 to be glued
6, a pressure contact surface 37 that contacts the original 30 and an elasticity imparting surface 38 that acts as an elastic leg are formed.

Next, on the upstream side of the elastic body 35, a projection 40 having an inclined surface 39 for preventing the leading edge of the original 30 being conveyed from riding on the elastic body 35.
Are formed. Further, the contact glass 34
Below, the light source 41, the mirror 42, the lens 43, and the CC
A reading optical system 45 according to D44 is provided, and a reduction optical system image sensor is configured.

In FIG. 2, the upper document guide 27 is turned upside down, the lower left side is the upstream side for conveying the document 30, and an ADF setting recess 46 (not shown) is formed. An opening 47 for the document feeding roller 31, a protrusion 40, an elastic body 35, and an opening 48 for the document discharging roller 33 are sequentially formed from the ADF setting recess 46. Therefore, in the case shown in FIG.
Is transported from the lower left to the upper right.

In such a structure, before the document 30 reaches the document reading section 32, the elastic body 35 is irradiated with the light from the light source 41 to set the optical reading standard. The document feeding roller 31 and the document discharging roller 33 are
The originals 30 rotate at the same peripheral speed and move in the original passage 29.
Are transported at a uniform feed rate. The image of this manuscript 30 is
It is read by the reading optical system 45. At this time, the document 30 is transported by the document transport roller 31 and the document discharge roller 33. Then, in the document reading unit 32, the document 30
Is pressed against the contact glass 32 by the elastic body 35,
Since this pressing force may be extremely weak, the conveyance resistance in this portion is low. When forming the document passage 29,
Since there is no obstacle in reading the original 30 even if the original 30 is formed with a sufficient interval so that the original 30 is not stuck, there is no portion where the conveyance resistance of the original 30 increases. That is, the dimensional accuracy of the gap of the document passage 39 can be made considerably rough. For this reason, the drive motor for driving the document transport roller 31 and the document discharge roller 33 can be sufficiently used even if its output is weak. Moreover, since the original 30 is pressed against the contact glass 32 by the elastic body 35, there is no possibility that the focal point is optically deviated.

[0016]

As described above, according to the present invention, the document passages are formed by the document guides opposed to each other, and the document feeding portion, the document reading portion provided with the contact glass and the document discharge roller are provided along the document passage. In the document reading apparatus sequentially arranged, the thin plate member is bent, and the elastic body pressed by the elastic force to the contact glass of the document reading unit is fixedly arranged on the document guide. Since the document conveying roller and the document discharge roller are provided, the elastic force of the elastic body that presses the document against the contact glass may be weak, which reduces the document conveyance resistance and reduces the drive motor size. Also, since the original is in close contact with the contact glass, the original passage can be roughly formed, and the interval between the original passages can be increased with a margin. Comb without focal position of the optical system is out of order even has an effect such as can perform a stable reading.

[Brief description of drawings]

FIG. 1 is a vertical side view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing an upper document guide by turning it over.

FIG. 3 is a vertical sectional side view showing a first conventional example.

FIG. 4 is a vertical sectional side view showing a second conventional example.

[Explanation of symbols]

 27 document guide 28 document guide 29 document passage 30 document 31 document transport roller 32 document reading unit 34 contact glass 35 elastic body

Claims (1)

[Claims] 1. A document reading apparatus in which a document path is formed by document guides opposed to each other, and a document reading section including a document feeding roller and a contact glass and a document discharging roller are sequentially arranged along the document path. An original reading device, wherein a thin plate member is bent and an elastic body that is pressed against the contact glass of the original reading unit by its elastic force is fixedly arranged on the original guide.