JP2842974B2 - Image reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus used for a facsimile, a copying machine, and the like.

[0002]

2. Description of the Related Art Information recorded on paper such as a manuscript is stored in a CCD.
(Charge Coupled Device) As an image reading apparatus that reads using an optical system such as an image sensor, for example, an image reading apparatus having a structure shown in FIG. 2 is known. The structure shown in FIG. 2 will be described. In FIG. 2, reference numeral 1 denotes a document sheet. The document sheet 1 is a plate-shaped document guide plate 4 (upper portion) and a document guide which are opposed to each other at a predetermined interval vertically. The document is conveyed along the document path 2 formed between the plates 3 (lower part). Then, the entrance side of the document path 2 (FIG. 2)
On the middle and right sides, a pair of rollers including a conveying roller 5 and a pinch roller 6 whose axes are arranged along the width direction of the document are respectively connected to the document guide plate 3 and the document guide plate 4 from the plate surface openings in the document path 2. Similarly, on the exit side (left side in FIG. 2) of the document path 2, a discharge roller 8 and a pinch roller 9 are respectively provided through the plate surface openings of the document guide plate 3 and the document guide 4. The transport roller 5 and the discharge roller 8 are connected to and driven by a motor (not shown).

Subsequently, an original reading window 20 is formed in the original guide plate 3 located in the middle of the conveying roller 5 and the discharge roller 8 so as to face the original passage 2 and to be arranged along the width direction of the original. An elongated rectangular contact glass 7 is fitted and held in the reading window 20 to provide a reading unit 21. The holding structure of the contact glass 7 has an L-shaped stepped section 30 on both sides of an edge portion of the document reading window 20 along the width direction of the document sheet 1 as shown in FIG.
Are formed facing each other, the glass 7 is dropped and fitted between the opposed L-shaped steps 30, and the interval between the flat ends of the opposed L-shaped steps 30 is used as the optical path of the reading unit 21. . When the glass 7 is fitted and held in the document reading window 20, the height of the upper surface of the glass 7 is set in advance in the L-shaped step portion so that the height is continuous with the upper surface of the document guide plate 3. Thirty steps are set.

Further, an optical system using a CCD image sensor 17 is provided inside the apparatus 10. First,
A light source 11 displaced at an oblique angle from the center line of the reading unit 21 is provided below the contact glass 7. The light source 11 has a dimension longer than the document width along the document width direction. The reading unit 21 is mounted horizontally with the light emission direction facing the center line of the reading unit 21. Below this light source 11, an elongated first reflecting mirror 12 arranged along the document width direction so as to reflect a point extending the center line of the reading unit 21 downward as an incident angle is attached, A second reflecting mirror 13 which receives and reflects the reflected light of the first reflecting mirror 12 so as to sequentially and optically oppose the first reflecting mirror 12, and a reflection by a third reflecting mirror 14 in a similar manner. Light 15 passes through a lens 16 and a CCD image sensor 17
And is read.

In such a configuration, the original sheet 1 is set on an original table connected to the upper surface of the original guide plate 3 and is transported one by one by a pair of rollers including a transport roller 5 and a pinch roller 6. Is conveyed to the reading section 21, the light beam of the light source 11 that is turned on irradiates the original sheet 1 on the reading line located on the surface of the glass 7 through the glass 7 of the original reading window 20, The information sequentially recorded on the original sheet 1 in accordance with the transport step is reflected light 15, passes through the first reflecting mirror 12, the second reflecting mirror 13, and the lens 16, and reaches the CCD image sensor 17.
And read. Then, the read original paper 1
Is sequentially sent out to the exit side of the document path 2 by the discharge roller 8 and the pinch roller 9. Further, data incident by the CCD image sensor 17 is sequentially stored in various memories through encoding processing and the like, and necessary data processing is performed.

[0006]

One problem with such an image reading apparatus is that one part of the dust 5 adhered to the original paper 1 or to the upper surface 3a of the original guide plate 3.
As shown by a two-dot chain line in FIG. 3, 0 enters the gap 18 between the side surface 7b of the glass 7 of the document reading window 20 and the L-shaped step portion 30, gradually accumulates in the L-shaped step portion 30, and The dust 50 deposited under the influence of vibrations and the like gradually goes around to the lower surface 7c of the glass 7 which is in surface contact with the glass 7 and finally falls into the inside 10 of the apparatus. If the fallen dust 50 adheres to the surface of the first reflecting mirror 12, there is a problem that recording and reproduction of an image is reduced, and the dust 50 is frequently removed from the maintenance service work, which is troublesome. Was occurring.

Therefore, the contact glass 7 is moved to the L-shaped step portion 3.
The inside of the apparatus is fixed with an adhesive in
It is conceivable to prevent the fall. However, the use of the adhesive is troublesome in assembling the apparatus. For example, a defect due to the protrusion of the adhesive, a defect in the surface height position of the glass 7 due to the adhesive, and the like are likely to occur. Feeding troubles occur, and the maintenance work for removing the dirt and dust 50 on the glass upper surface 7a becomes a troublesome work for removing the glass 7.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image reading apparatus which solves the above-mentioned conventional problems with respect to dust and is excellent in quality assurance and cost of the apparatus as well as in maintenance service workability. I do.

[0009]

According to the present invention, a manuscript sheet on which image data is recorded is placed along a manuscript guide plate surface facing the image data recording surface and a reading section is provided from the entrance side of the guide plate. Transport means for transporting the paper toward the exit side, and continuous with the document guide plate surface, opening in a rectangular shape elongated in the width direction on the guide plate surface, provided on both sides facing each other, and facing downward. A side portion and a lower end of the side portion are provided at a predetermined distance from the side portion and are provided with a curved portion facing inward and upward to form a receiving portion having a distal end of the curved portion as a support portion, and a lower portion opposed to both ends. A reading window having an end face portion is formed. The reading window is dropped into the window so as to close the reading window, the lower surfaces on both sides are supported by the support portions of the receiving portions, and each side surface is formed by the end face portion and the side surface. Rank The determined by a light-transmitting plate is provided, which is constituted of an image reading apparatus formed by arranging the optical reading section inwardly of said read window.

[0010]

The original paper is set on an original table connected to the upper surface of the original guide plate, and the original paper is sequentially read by the transport unit in accordance with a transport step by the transport unit, and information recorded on the original paper is sequentially read by the optical reading unit and transported. The document is sent to the exit side of the document path by the means. While the manuscript paper is being conveyed to the translucent part of the reading unit, dust adhering to the manuscript paper or dust adhering to the upper surface of the manuscript guide plate is also moved, and these dusts are opposed to the manuscript reading window. It was deposited on the inner bottom of the receiving part provided at the lower end of the side part from the gap between the side surface of the light transmitting plate dropped and held between the side parts, and the inside of this receiving part acted as a dust receiving part and was deposited Even if the dust receives external vibrations or vibrations of the device, the dust does not push up the light transmitting plate because the lower surface of the light transmitting plate is supported by line contact at the support portion.
It does not fall into the device from the lower surface of the light transmitting plate.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described. The overall configuration of an image reading apparatus is the same as the apparatus shown in FIG.
0 will be described with reference to FIG. First, the document reading window 20 is formed with an opening in the document guide plate 3, and the opening edge 3 a is formed at both ends of the document sheet 1 along the conveying direction and on both sides of the document sheet 1 along the width direction. End faces 22, 22 and side face 2 bent at substantially right angles
3 and 23 are provided, and the shape of the side portions 23 and 23 is formed at the lower end thereof with a predetermined distance from the side portion 23 and is bent upward, and the distal end of the bent portion 24 is used as a support portion 25. The receiving portion 40 may have a substantially V-shaped cross section or a substantially U-shaped similar shape.

The holding means for holding the contact glass 7 is such that the supporting portion 25 at the front end of the receiving portion 40 opposed to the receiving portion 40 has a lower glass surface 7c.
On the four side surfaces 7b of the glass 7, there are provided end faces 22, 22 and side faces 23, 2, which are bent substantially perpendicularly to the edge of the document reading window 20 downward.
The glass 7 acts as an opposing receiving surface, and the glass 7 is dropped into the document reading window 20 by a clearance fit and held.

The height of the reading section 21 shown in FIG. 1 is such that the glass upper surface 7a is not protruded from the upper surface 3a of the original guide plate on the side surface portion 23 located on the upstream side in the conveying direction of the original paper 1. Receiving end support 25
The height of the glass is determined by the upper surface 7a of the glass and the upper surface 3a of the document guide plate.
The dimension of the document guide plate upper surface 3a is set so that the dimension becomes plus 0 and somewhat minus dimension, and the side surface portion 23 located on the downstream side in the transport direction of the document sheet 1 is opposite to the upstream side. The glass upper surface 7a is set to the height dimension of the supporting portion 25 at the tip end for receiving the glass lower surface 7c so that the glass upper surface 7a protrudes from the document guide plate upper surface 3a. Each is set to the dimensions.

In such a configuration, the original sheet 1 is set on an original table connected to the upper surface 3a of the original guide plate, and the leading end of the original sheet 1 is moved by a pair of rollers composed of the transport roller 5 and the pinch roller 6 to the upper surface 3a of the original guide plate. In the process of being conveyed to the contact glass upper surface 7a of the reading unit 21, the portion of the original reading window 20 and the glass 7 with respect to the upstream position is slightly lowered in size with respect to the original guide plate upper surface 3a. And the upper surface 3a of the document guide plate with respect to the side surface located on the downstream side of the glass 7 is slightly higher than the upper surface 3a of the document guide plate with respect to the upper surface 3a of the document guide plate. As a result, the leading edge of the document sheet 1 is smoothly transported without being caught on the side surface 7 b of the glass 7 or the side portion 23 of the document guide plate 3.

The original paper 1 is placed on the upper surface 3a of the original guide plate.
The dust is also moved in the process of being conveyed to the glass upper surface 7a from the side, and a portion of the dust 50 is removed from the gap 18 between the side surface portion 23 of the document reading window 20 and the side surface 7b of the glass 7 by the inner bottom portion of the receiving portion 40. And the inside of the receiving part 40 acts as a dust receiving part, and the dust 50 deposited inside is supported by the supporting part 25 at the tip of the glass lower surface 7c by line contact even when receiving external vibration or vibration of the device. Therefore, the dust 50 does not push up the glass 7, does not fall from the glass lower surface 7 c to the inside 10 of the apparatus, and does not cause a problem such as a decrease in image recording / reproduction due to the dust 50.

Further, in the maintenance service work for removing the dust 50, since the glass 7 is not fixed with the adhesive, the work for attaching and detaching the glass 7 can be easily performed, and the original reading window 20 can be removed.
After removing the glass 7 dropped and held by the clearance fit and removing the dust 50 deposited on the inner bottom of the receiving portion 40, the glass 7 may be dropped into the document reading window 20 and held, so that the operation is simple. And the frequency of service work is low. The document reading window 20 is
Since the glass 7 is supported by the support portions 25 at both ends of the receiving portion 40, it is possible to increase the substantial opening area of the document reading window 20 as compared with the conventional example, so that the document irradiation surface and the reading surface of the light source 11 can be reduced. Can be wide.

Subsequently, the light source 11 is turned on just before the original sheet 1 is conveyed to the reading section 21, and the light beam of the light source 11 passes through the glass 7 of the original reading window 20 and the glass upper surface 7.
a, the information recorded on the original sheet 1 is sequentially reflected along with the step of transporting the original sheet 1 along with the reflected light 15, the first reflecting mirror 12, the second reflecting mirror 13, and the lens. The light enters the CCD image sensor 17 through 16 and is read. Then, each read original sheet 1
Is sequentially sent out to the exit side of the document path 2 by the discharge roller 8 and the pinch roller 9.

In the above-described embodiment, the conveying means for driving the original paper 1 employs the conveying means driven by the pair of rollers 5 and 6. However, the conveying means is not limited to the pair of rollers but may use a belt or other known means. The contact glass 7 is not limited to glass, but may be a light-transmitting plate using plastics. The image sensor is not limited to CCD but may be a MOS image sensor, for example. The optical reading unit such as the light source and the image sensor arranged in the above-mentioned configuration can adopt another arrangement or another configuration.

[0019]

According to the present invention, a reading window having a receiving portion is provided on both sides of the opening of the document guide plate. The reading window is dropped into the window so as to close the reading window, and the lower surfaces on both sides are respectively formed. Since the reading unit is configured by providing a translucent plate that is supported in contact with the supporting unit of the receiving unit, dust or an original guide adhered to the original paper during the process of transporting the original paper to the translucent unit of the reading unit The dust adhering to the upper surface of the plate is simultaneously moved and accumulated on the inner bottom of the receiving portion through a gap between the side surface of the light transmitting plate dropped and held between the side portions of the document reading window. Acting as a receiving part, the accumulated dust
Even if external vibrations or vibrations of the apparatus are received, the lower surface of the light transmitting plate is supported by the supporting portion by line contact, and therefore, does not fall into the inside of the apparatus from the lower surface of the light transmitting plate. In addition, the maintenance service work for removing dust has effects that the light-transmitting plate can be easily attached and detached since the light-transmitting plate is not fixed with an adhesive, and the frequency of the service operation can be reduced.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing the configuration of an embodiment of the present invention.

FIG. 2 is a sectional view showing a conventional example.

FIG. 3 is a partial sectional view showing a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 original paper 3 original guide plate 3 a original guide plate surface 5 transport roller (transport unit) 6 pinch roller (transport unit) 7 light-transmitting plate 11 light source (optical reading unit) 17 image sensor (optical reading unit) 20 reading window 21 reading Part 22 End face part 23 Side part 24 Curved part 25 Support part 40 Receiving part

Claims (1)

(57) [Claims] An original sheet on which image data is recorded is conveyed from an entrance side of the guide plate to an exit side via a reading unit along an original guide plate surface facing the image data recording surface. A conveying means is provided, which is continuous with the document guide plate surface, is elongated in the width direction on the guide plate surface, has a rectangular opening, is provided on both sides to face each other, and a downwardly directed side portion and a lower end of the side portion are provided. And a curved portion which is provided at a predetermined distance from the side surface portion and is directed upward and inward to form a receiving portion having a front end of the curved portion as a support portion and a downwardly facing end face portion formed at both ends. A light-transmitting plate which is provided with a window, is dropped into the window so as to close the reading window, the lower surfaces on both sides are respectively supported by the supporting portions of the receiving portions, and the respective side surfaces are positioned at the end surface portion and the side surface portion. Provided Image reading apparatus being characterized in that disposed an optical reading section inwardly of said read window.