JPH09307695A - Original reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To read an original image with stable image quality by providing a press contact prevention means inhibiting contact of original paper to a part of a read reference member through which a read light or a reflected light is transmitted so as to suppress dirt on a read glass plate by an unfixed material. SOLUTION: An original read section is made up of a read system means reading optically an image of original paper P set to a copying machine main body and an automatic document feed means arranged to an upper face of the copying machine main body in an opening/closing enable way. Then a step difference forming member 2a (press contact prevention means) is arranged on a read reference member 1 and a background part forming member 3 is arranged apart from and opposite to the read reference member 1. Since an unfixed material for the original paper P is not stuck to a part of the read reference member 1 by providing the step difference forming member 2a avoiding contact of the original paper P with the part of the read reference member 1 through which a read light or a reflected light is transmitted, the dirt of the read reference member 1 is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document reading device used as an image input device in a copying machine, a scanner and the like, and more particularly to a document reading device of a system for reading an image while moving a document sheet.

[0002]

2. Description of the Related Art Conventionally, in the above-mentioned document reading device, there are a system of reading an image while fixing a document and a system of reading the image while moving a document sheet.

The former method is generally called a platen method, and a document reading apparatus according to the method is, for example, a platen glass on which a document sheet is placed, and rotatably fixed above the platen glass. Platen cover, an illumination lamp movably arranged below the platen glass, and a CC in which a large number of photoelectric conversion elements are arranged.
It has a D sensor and an optical element such as a mirror for inputting the reflected light from the original document to the CCD sensor, and outputs the image information from the CCD sensor while moving the illumination lamp, so that the original image on the original paper is displayed. Reading.

On the other hand, the latter method is generally Const.
It is called an ant velocity transport method (hereinafter referred to as a CVT method), and a document reading apparatus according to the method includes, for example, a document tray on which a document sheet is placed, a document discharge tray for discharging the document sheet, and a document tray. From a document transfer tray to a document transfer tray, a document sheet conveying unit, a reading glass arranged along the document conveying path, and a reading glass arranged on the opposite side of the reading glass from the document conveying path. The illumination lamp and a CCD sensor arranged in parallel with the illumination lamp are provided, and the image information is output from the CCD sensor while moving the document sheet to read the document image on the document sheet. Hereinafter, these read images are referred to as read images.

In these document reading devices, in order to read the image of the document, that is, it is necessary to pass the focal point of the CCD sensor so that the reflected light from the document sheet forms an image at the CCD sensor. The platen glass and the reading glass function as a reference plate. In the following description, the side surface of the reading glass or the like on the side of the original conveyance path, and the portion through which the irradiation light of the illumination lamp and the light reflected by the original are transmitted is referred to as the reading surface of the reading glass or the like.

However, in the above document reading apparatus, when the correction liquid, the ink for the ballpoint pen, etc. are placed on the document tray or the like without being fixed and the reading is started, the unfixed material is read. It adheres to glass etc. When the unfixed material adheres to the reading surface of the reading glass or the like, light is blocked by the unfixed material, so that black spots or white spots occur in the read image. In particular, in the CVT type document reading device,
If unfixed material adheres to the reading surface, the entire image corresponding to it cannot be read, and black streaks and linear image dropouts occur. Deterioration was not negligible.

Further, particularly in the CVT type document reading apparatus, since the image is read while the document is being fed without being fixed, the mutual positional relationship between the document sheet and the focal position cannot be sufficiently stabilized. The original document image could not be read with sufficient image quality because the original document feed speed at the focus position could not be sufficiently stabilized. It should be noted that these problems occur as a result of, for example, the original paper being skewed.

Further, in the above document reading apparatus, when reading an image on a transparent or translucent document sheet such as a tracing paper, the irradiation light of the illumination lamp passes through the document sheet, so that the read image of the read image is read. The background part may be covered. Note that this phenomenon is generally called show-through.

Therefore, even in the past, in order to solve these problems, a flat plate (for example, a platen cover) is arranged facing the reading glass or the like, or
A technique has been proposed in which a sheet feeding roll is arranged by being brought into pressure contact with the reading glass.

However, when the former flat plate is used for a CVT type document reading device, the irradiation light transmitted through the document sheet is reflected to prevent show-through, and the mutual position between the document sheet and the focal point position is reflected. Although the relationship can be stabilized to some extent, it is not possible to prevent the reading glass from being contaminated by the unfixed material or to stabilize the feeding speed of the document sheet at the focal position.

Further, when the latter paper feed roll is used for a CVT type document reading device, show-through is prevented,
It is possible to stabilize the mutual positional relationship between the original paper and the focus position to some extent or to stabilize the feed speed of the original paper at the focus position, but it was not possible to suppress the stain on the reading glass due to the unfixed material. . In particular, when the paper feed roll is pressed against the reading surface, the mutual positional relationship between the original paper and the focal position can be highly stabilized, but dirt adhering to the surface of the roll is pressed against the reading surface. There is a problem in that the image quality is remarkably deteriorated due to the stain on the reading glass, because of the adhesion.

[0012]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to develop a CVT type document reading apparatus capable of reading a document image with stable image quality by suppressing stains on the reading glass due to unfixed material. .

[0013]

SUMMARY OF THE INVENTION That is, according to the present invention, a document placing table on which a document sheet is placed, a document ejecting table from which the document sheet is ejected, and a document sheet from the document placing table to the document ejecting table An original sheet conveying means for conveying sheets one by one, a transparent or semi-transparent reading reference member arranged along the original conveying path, and an opposite side of the reading reference member to the original conveying path, A document that has a reading unit that irradiates a reading light onto a document sheet through a reading reference member and reads an image on the document sheet based on the reflected light from the document sheet, and reads the document image while conveying the document sheet. In the reading device, a document reading device is provided with contact preventing means for preventing a document sheet from coming into contact with a portion of the reading reference member through which the reading light or the reflected light is transmitted.

In the present invention, the original placing table may be any one capable of placing original sheets, for example, an original sheet tray.

The original discharge table may be any one on which original sheets can be placed, for example, an original discharge tray.

The above-mentioned document sheet conveying means is only required to convey the document sheets one by one from the document placing table to the document discharging table. For example, a plurality of document sheets are arranged from the document placing table to the document discharging table. It can be configured with a transport roll. It should be noted that the document transportation path means a transportation path of the document sheet set between the document placing table and the document discharging table by the document sheet transportation means.

The reading reference member may be any member that is disposed along the document transport path and is made of a transparent or semi-transparent material. For example, a reading glass formed in a long flat plate shape may be used. is there.

The reading means is disposed on the opposite side of the reading reference member from the original conveying path, and irradiates the reading paper onto the reading paper through the reading reference member and reflects the reflected light from the reading paper. Any image can be read on the basis of the original, and for example, it can be constituted by an illumination lamp and a CCD sensor arranged side by side on the opposite side of the reading reference member from the original conveying path.

The contact preventing means may be any one that functions so as not to contact the original sheet with the area of the reading reference member through which the reading light or the reflected light is transmitted. It is arranged on the side opposite to the member, and is composed of a paper suction member for sucking the original paper by electrostatic suction force or negative pressure of air, or between the reading reference member and the original conveying path, A step forming member that is provided other than between the portion of the reading reference member through which light or reflected light is transmitted and the document conveyance path and forms a step between the side surface of the reading reference member on the side of the original conveyance path. be able to.

The step forming member may be any member that can form a step between the reading reference member and the side surface of the reading reference member on the side of the original conveyance path. For example, a plate material having a predetermined thickness is arranged on the reading reference member. Just set it up. Even if the plate material is formed separately from the reading reference member and is disposed on the reading reference member by being attached to the reading reference member, it is formed integrally with the reading reference member. It may be arranged on the reading reference member. It should be noted that the size of the step may be set and the distance between the step and the reading surface may be set so that the most stiff original sheet does not come into contact with the reading surface.

It is preferable that the step has a distance between the focus position of the reading means and 2 mm or more and 5 mm or less and a step size of 0.3 mm or more and 0.7 mm or less. Thus, not only can the original sheet not be attached to the reading surface, but also the original sheet can be set so as to stably pass through the focal position of the reading means, and the feeding speed of the original sheet at the focal position can be set. It can be stabilized and the irradiation light of the illumination lamp is not blocked by the step forming member.

Further, it is preferable that the step forming member is arranged on the upstream side of the reading surface in the conveying direction of the original sheet rather than on the downstream side. This is because when forming a step on the downstream side of the document sheet in the transport direction, it is necessary to form a slope between the step forming member and the reading surface so that the sheet does not get caught in the step, and the step forming member is correspondingly formed. This is because the reading surface and the reading surface must be separated from each other, and the above step must be made large.

Further, it is preferable that the step forming member is formed of a material having a low friction coefficient on its side surface on the side of the original feeding path.
For example, glass, high molecular weight polyethylene, fluororesin, polyacetal (POM), nylon and the like can be used. As a result, it is possible to prevent the original sheet from twisting due to the friction between the original sheet and the step forming member.

Further, in the document reading apparatus of the present invention, the contact preventing means is provided so that the document sheet is not brought into contact with the portion of the reading reference member through which the reading light or the reflected light is transmitted. Even if the original image of the original sheet is read, the unfixed image does not adhere to the part of the reference member.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION By the way, the present invention can be used in a document reading apparatus in which a background portion forming member is arranged so as to face the above-mentioned reading reference member, or a paper feeding means is arranged so as to face the above-mentioned reading reference member. It can also be used in a document reading device.

The background portion forming member may be arranged so as to face the reading reference member and reflect the irradiation light transmitted through the original sheet. For example, the background portion forming member may be arranged so as to face the reading surface. There is a flat plate.

The sheet feeding means may be arranged so as to be opposed to the reading reference member and stabilize the feeding speed of the original sheet at the focal position. For example, the sheet feeding arranged in pressure contact with the reading reference member. There is a roll. Since the original paper has a predetermined thickness, the paper can be conveyed if the paper feed roll is opposed to the reading reference member with an interval narrower than the thickness.
Specifically, the paper can be conveyed if it is 0 to 0.3 mm. The paper feeding means may be arranged so as to be in pressure contact with the reading surface so as to also function as the background portion forming member.

When these techniques are combined with the present invention, the paper feed means is pressed against the step forming member rather than pressed against the reading reference member.
It is preferable that the side surface of the step forming member on the side of the original feeding path is formed of a material having a lower friction coefficient than that of the sheet feeding means. For example, glass, high molecular weight polyethylene, fluorine resin, P
There are OM, nylon, etc. As a result, it is possible to prevent the feeding of the original document from becoming unstable due to friction between the original document and the step forming member. In particular, when the surface of the step forming member is formed of a material having a friction coefficient lower than that of glass conventionally used as a reading reference member, for example, high-molecular polyethylene, it is more than that when the document feeding unit is pressed against the reading reference member. The original paper can be stably conveyed.

Further, when these techniques are combined with the present invention, the paper feeding means is arranged in pressure contact with the reading surface so that the paper feeding means does not have the function of the background portion forming member but also the paper feeding means. It is preferable that both the means and the background portion forming member are arranged adjacent to each other. With this, not only can the paper feeding means prevent the reading surface from being contaminated, but also when the paper feeding means is formed of a paper feeding roll, the outer shape can be set small, and moreover, the paper feeding means can be applied to the original paper. Since the carrying force is applied, the distance between the background portion forming member and the reading reference member can be narrowed so that the document sheet does not deviate from the focus position (that is, the image quality of the read image (distortion or image distortion). ) Is improved). In addition, even in the past,
Considering the image quality of the read image, it is preferable that the distance between the read reference member and the background portion forming member is a narrow distance (0.5 to 1.0 mm) so that the paper does not shift from the focus position. In such a case, the feed speed of the document sheet becomes unstable due to the friction between the document sheet and these members, so that in actuality, a wide interval (1.0 to Had to be set to 1.5 mm).

Further, when the paper feeding means and the background portion forming member are used together, there is no possibility that the paper feeding means faces the reading surface and affects the image quality. Therefore, as the paper feeding means, a vibrating conveyance such as a piezo element is carried out. Members can be used.

Further, the present invention relates to a so-called CVT type document reading device, and a platen glass on which a document sheet is placed, a platen cover rotatably fixed above the platen glass, and the platen described above. A so-called platen having an illuminating lamp movably arranged under the glass, a CCD sensor in which a large number of photoelectric conversion elements are arranged, and an optical element such as a mirror for inputting reflected light from an original document to the CCD sensor. It is also possible to form one document reading device in combination with the system document reading device.

In combining these techniques, it is advisable to use the document placing table, the document discharging table and the document sheet conveying means as a part of an automatic document feeder for feeding the document sheet to the platen glass. In this case, the document placing table, the document discharging table, and the document sheet conveying means may be integrally formed with the platen cover and arranged to be openable and closable with respect to the reading reference member. In the following, the member on which the platen glass and the document placing table are arranged is referred to as a reading device body, and is arranged so as to be openable and closable with respect to the reading device body, and the platen cover and the document sheet conveying means are arranged. The existing member is called the cover body. Further, in that case, the background portion forming member and the paper feeding means may be arranged on the reading device body side or may be arranged on the cover body side.

When the background portion forming member and the paper feeding means are arranged on the cover body side, a supporting member which is arranged so as to be swingable with respect to the cover body is provided, and the supporting member is formed on the cover member. A background portion forming member and a sheet feeding unit may be provided so that the support member is swung when the cover body is closed. As a result, even if the positioning accuracy of the cover body with respect to the reading device body is not sufficient, the paper feeding means and the step forming member are brought into contact with each other to cause the paper feeding means and the background portion forming member to read the reading reference member (reading). It is possible to easily position the surface.

Further, in this structure, as a method for improving the accuracy of the distance between the background portion forming member and the reading reference member, for example, a paper feeding roll is used as the paper feeding means, and opening / closing is performed around the rotation axis of the roll. A background portion forming member is arranged as much as possible, a spacer having a height corresponding to the distance from the reading reference member is arranged on the background portion forming member, and the background portion forming member is pressed against the reading reference member side. It is sufficient to provide a pressing force applying member for As a result, the paper feed roll is brought into contact with the reading reference member or the step forming member over the entire width, so that the interval can be made constant in the rotation axis direction of the roll, and the spacer is used as the reading reference member. Alternatively, the gap can be made to be a desired one in the sheet conveying direction by abutting on the step forming member, so that the precision of the gap can be improved.

Hereinafter, some examples of specific combinational configurations of the present invention will be described with reference to the accompanying drawings.

(Structural Example 1) The document reading apparatus shown in FIG.
A step forming member 2a is provided on the reading glass 1, and
The reading glass 1 and the step forming member 2a are opposed to and apart from each other, and a flat plate-shaped plate 3 is arranged. In addition, P in the drawing indicates a manuscript paper sheet, and R indicates a reflection direction of reflected light by the manuscript paper sheet (the same applies to the following configuration examples).

(Structure Example 2) The document reading device shown in FIG.
A step forming member 2a is provided on the reading glass 1, and
This is a configuration in which the background portion roll 3b is disposed so as to face the reading glass 1 and be separated therefrom.

(Structural Example 3) The document reading apparatus shown in FIG.
This is a configuration example in which a flat plate-shaped plate 3 is arranged so as to face the reading glass 1 and is separated therefrom, and a sheet suction member 2b is arranged at a position facing the reading surface.

(Structure Example 4) The document reading device shown in FIG.
A step forming member 2a is arranged on the reading glass 1, and a flat plate-shaped plate 3 is provided so as to face the reading glass 1 and be spaced apart from the reading glass 1.
Is provided, and the sheet feed roll 4a is arranged in pressure contact with the step forming member 2a.

(Structure example 5) The document reading apparatus shown in FIG.
A step forming member 2a is arranged on the reading glass 1, and a flat plate-shaped plate 3 is provided so as to face the reading glass 1 and be spaced apart from the reading glass 1.
Is arranged, and the vibration transfer member 4b is arranged in pressure contact with the step forming member 2a.

(Structural Example 6) The document reading apparatus shown in FIG.
A flat plate-shaped plate 3 is arranged facing the reading glass 1 and apart from each other, and a sheet suction member 2b is arranged at a position facing the reading surface. This is a configuration example in which the sheet feed roll 4a is arranged in pressure contact with the sheet feeding roll 4a. The following configuration example is based on the plate 3
6 is a configuration example in which the sheet feeding means 4 is arranged in the cover body.

(Structure Example 7) The document reading apparatus shown in FIG.
Support arm 5 swingably arranged with respect to the cover body
The plate 3 and the paper feed roll 4a are arranged to be openable and closable, a spacer is arranged on the plate 3, and an elastic force applying member 7 for pressing the plate 3 against the reading glass 1 is arranged. Here is an example.

(Structure Example 8) The document reading apparatus shown in FIG.
Support arm 5 swingably arranged with respect to the cover body
In the configuration example, the plate 3 is arranged to be openable and closable, and the plate 3 is provided with a spacer and a vibration conveying member 4b.

(Structure Example 9) The document reading device shown in FIG.
Paper suction member 2 together with plate 3 and paper feed roll 4
It is an example of composition which arranged b in a cover body.

[0045]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

Embodiment 1 FIG. 10 shows a digital copying machine to which the present invention is applied. In the digital copying machine, a document sheet Ps is placed, a document reading unit that reads an image of the document sheet Ps as image information by a platen system or a CVT system, an image storage unit that stores the image information, and the image storage unit. The image forming unit forms an image on the recording paper Po based on the image information stored in the unit.

The above-mentioned document reading section is a reading system means arranged in the main body of the copying machine to optically read an image on the document sheet Ps.
The automatic document feeder is arranged to be openable and closable with respect to the upper surface of the main body of the copying machine.

The reading system means includes a platen glass 16 disposed on the upper surface of the main body of the copying machine, and the platen glass 1 concerned.
6, a reading glass 1 arranged in parallel at one end side, a first carriage 17 disposed below the reading glass 1 as a home position and movable to the other end side of the platen glass 16, and the first carriage 17. It has a second carriage 18 that moves in conjunction with the carriage 17, and a CCD sensor 19 provided under the home position of the first carriage 17. The first carriage 17 includes an illumination lamp and a reflection plate, and an illumination member 17a for irradiating the original paper Ps with irradiation light, and a first mirror 17b for reflecting the irradiation light of the original paper Ps. And a second mirror and a third mirror for causing the light reflected by the first mirror 17b to enter the CCD sensor 19 on the second carriage 18. In the following, the entire portion where the light emitted from the illumination member 17a at the home position, reflected by the original sheet Ps, reflected by the mirrors and incident on the CCD sensor 19 intersects with the upper surface of the reading glass 1 will be described below. Is called a reading surface S. The position on the reading surface S corresponding to the focus of the CCD sensor 19 is called the center of the reading surface S (the position where the alternate long and short dash line in FIG. 12 intersects the reading glass 1).

The automatic document feeding means is provided at a position facing the platen glass 16 of the feeding means frame 8 which is openably and closably arranged in the copying machine body, and has a white surface. A platen glass cover 15 having a platen glass cover and a document placing tray 1 which is disposed on the upper surface side of the feeding means frame 8 and on which a plurality of document sheets Ps can be placed.
4 and a document sheet feeding member that carries in the document sheets Ps one by one from the document placing tray 14, passes them on the reading glass 1, and then discharges them onto the upper surface of the feeding means frame 8. In FIG. 10, 11 is a pickup roll that draws the original paper Ps from the original placing tray 14, 12 is a registration roll that sends the original paper Ps to the reading glass 1, and 13 is a discharge that discharges the original paper Ps onto the feeding means frame 8. Rolls 10, upstream chutes, 9 downstream chutes, all of which are the above-mentioned document sheet feeding members, are arranged in the above-mentioned feeding means frame 8.

In the digital copying machine, when the original sheet Ps is placed on the platen glass 16,
While the image of the document sheet Ps is read and an image corresponding to the document image is formed on the recording sheet Po, when the document sheet Ps is placed on the document placing tray 14, the document sheet Ps is read. The image is read and an image corresponding to the original image is formed on the recording paper Po. In the following, the former will be called the platen mode and the latter will be called the CVT mode. The platen glass 1 is used in the platen mode.
In order to place the document sheet Ps on the sheet 6, the automatic document feeding means is opened, the document sheet Ps is placed on the platen glass 16 and then the automatic document feeding means is closed, as shown in FIG. Good.

In the platen mode, the document reading unit illuminates the document sheet Ps on the platen glass 16 by moving the two carriages 17 and 18 after operating the illumination lamp and the CCD sensor 19. While scanning with the member 17a, the reflected light from the document sheet Ps is input to the CCD sensor 19 to read the image on the document sheet Ps.

On the other hand, in the CVT mode, the document reading section operates the illumination lamp and the CCD sensor 19 and then operates the document sheet feeding member to pass the document sheet Ps on the reading glass 1. At the same time, the image on the original sheet Ps is read through the reading glass 1.

The image forming section includes a recording sheet accommodating tray 29 for accommodating a large number of recording sheets Po, and a toner image transfer member for forming a toner image on the recording sheet Po according to the image information stored in the image storage section. , The toner image on the recording paper Po
A toner image fixing member for fixing the recording paper, a recording paper discharge tray 28 for storing the recording paper Po on which the image is formed, and a recording paper discharge tray from the recording paper storage tray 29 via the toner image transfer member and the toner image fixing member. It has a recording paper Po feed member that conveys the recording paper Po to 28.

The toner image transfer member is a photoconductive drum 2 which is arranged so as to be openable and closable so as to face the recording sheet conveying path.
3, the photosensitive drum 23 is charged to a uniform potential by the uniform charging corotron 22, and the photosensitive drum 23 is exposed by the laser exposure means 21 to form an electrostatic latent image.
Then, the electrostatic latent image is developed to form a toner image, and the toner image is transferred to the recording paper Po by a transfer corotron arranged to face the photoconductor drum 23 via the recording paper conveyance path. The toner image corresponding to the image information stored in the image storage unit is formed on the recording paper Po.

Then, the image forming section forms a toner image on the photosensitive drum 23 according to the image information, transfers and fixes the toner image onto the recording paper Po, and further, onto the recording paper discharge tray 28. By discharging the recording paper Po, an image is formed on the recording paper Po.

By the way, in this embodiment, a high molecular polyethylene tape as the step forming member 2a is attached to the reading glass 1 on the upstream side of the reading surface S, while facing the reading surface S of the reading glass 1. The white plate 3 having a flat plate shape is disposed so as to be separated from each other, and the paper feed roll 4a made of silicon is pressed against the step forming member 2a.

Further, in this embodiment, the feeding means frame 8
The support arm 5 is swingably disposed on the support arm 5, and the plate 3 and the paper feed roll 4a are rotatably disposed on the support arm 5, so that the plate 3 and the paper feed roll 4a are arranged in the automatic document feeder. I have set up.

Further, in this embodiment, the support arm 5 is arranged so that the paper feed roll 4a is pressed against the step forming member 2a.
A first spring 6 which applies an elastic force to the plate 3, a second spring 7 which applies an elastic force to the plate 3 so that the free end side of the plate 3 is pressed against the reading glass 1, and a reading of the plate 3. By disposing the spacer 3a on the side surface facing the glass 1, regardless of the positioning accuracy of the automatic document feeder with respect to the main body of the copying machine, the plate 3 and the step forming member 2a with respect to the reading glass 1 and the step forming member 2a are provided. The paper feed roll 4a can be accurately positioned.

In this embodiment, the distance between the center of the reading surface S and the step forming member 2a is set to 5 mm, and the step size is set to 0.3 mm. Further, in this embodiment, the minimum distance between the plate 3 and the reading glass 1 is set to 0.5 mm. Further, the paper feed roll 4a was set to be pressed against the step forming member 2a at a position 8 mm from the center of the reading surface S. By the way, the distance between the center of the reading surface S and the end of the reading surface S on the upstream side in the sheet conveying direction is 5 mm, and if the distance is set to 2 mm or less, the amount of light incident on the CCD sensor 19 is reduced. Will decrease.

Then, in this embodiment, the original paper Ps coated with the non-dried correction fluid was read by the digital copying machine. As a result, in the above digital copying machine,
A large amount of the correction liquid adhered to the step forming member 2a, but did not adhere to the reading surface S at all. Further, when the normal document paper Ps was read by the digital copying machine after the reading was completed, no image quality defect due to white streaks or black streaks occurred.

Incidentally, in the above digital copying machine,
When the degree of adhesion between the reading glass 1 and the original sheet Ps was measured by changing the step size to 0.3 mm and 0.5 mm,
In both cases, the original paper Ps hung 0.2 mm at the position 5 mm downstream of the step regardless of the size of the step. In addition, when the reading glass 1 was checked for dirt in the digital copying machine, no dirt was found from the step to at least 7 mm downstream thereof.
Further, in the above digital copying machine, 5 m downstream of the step
When the center of the reading surface S was set to the position m, and the deviation of the magnification of the read image was examined, it was found that 1 m from the reading surface S
Even when the distance was m, the deviation of the magnification of the read image was at a level without any problem.

From the above, in the digital copying machine of this embodiment, the distance between the center of the reading surface S, that is, the focus position of the reading means and the step is 2 mm or more and 5 mm or less, and the step size is large. Is 0.3 mm or more and 1.3 mm or less, not only can the reading surface S be prevented from becoming dirty, but
The focus position of the reading means can be set so that the document sheet Ps can pass stably, and the document sheet Ps at the focus position can be set.
Of the lighting member 1 can be stabilized.
The irradiation light of 7a is not blocked by the step forming member 2a.

Comparative Example 1 The digital copying machine of this comparative example comprises a reading glass 1 of the digital copying machine to which the above-mentioned embodiment is applied, and a paper feed roll 4a made of silicon is pressed on the upstream side of the reading surface S thereof. Is. Further, the paper feed roll 4a is attached to the feed means frame 8 via a support arm 5 which is swingably arranged, and the support arm 5 presses the paper feed roll 4a against the reading glass 1. The elastic force is applied so that
The position where the paper feed roll 4a of the reading glass 1 is pressed is referred to as a pressing position. In addition, in this comparative example, the distance between the pressure contact position and the center of the reading surface S was set to 8 mm.

In this comparative example, the original paper Ps coated with the non-drying correction liquid was read by the digital copying machine. As a result, in the above digital copying machine,
A large amount of the correction liquid has adhered to the reading glass 1.
Further, the range extends over a wide range from the upstream side to the downstream side of the pressure contact position, and particularly on the downstream side of the pressure contact position, the correction liquid adheres even at a position 10 mm or more away from the pressure contact position. . Further, when the normal manuscript paper Ps is read by the digital copying machine after the reading is completed, an image quality defect due to white streaks and black streaks occurs in the entire image.

[0065]

As described above, in the original reading device of the present invention, the contact preventing means for preventing the original paper from coming into contact with the portion of the reading reference member through which the read light or the reflected light is transmitted is provided, and the unfixed material of the original paper is not provided. Since it does not adhere to the part of the reading reference member, the reading glass can be prevented from being contaminated by the unfixed material and the original image can be read with a stable image quality.

[Brief description of drawings]

FIG. 1 is a configuration example (1) of a main part of a document reading apparatus to which the present invention is applied.

FIG. 2 is a configuration example (2) of a main part of a document reading apparatus to which the present invention is applied.

FIG. 3 is a configuration example (3) of a main part of a document reading apparatus to which the invention is applied.

FIG. 4 is a configuration example (4) of a main part of a document reading apparatus to which the present invention is applied.

FIG. 5 is a configuration example (5) of a main part of a document reading apparatus to which the present invention is applied.

FIG. 6 is a configuration example (6) of a main part of a document reading apparatus to which the present invention is applied.

FIG. 7 is a configuration example (7) of a main part of a document reading apparatus to which the present invention has been applied.

FIG. 8 is a configuration example (8) of a main part of a document reading apparatus to which the present invention has been applied.

FIG. 9 is a configuration example (9) of a main part of a document reading apparatus to which the present invention has been applied.

FIG. 10 is a schematic configuration diagram of a digital copying machine according to the first embodiment of the present invention.

FIG. 11 is an explanatory diagram of a procedure for placing a document sheet on a platen glass in the digital copying machine of FIG.

FIG. 12 is a configuration diagram of the periphery of a reading glass of the digital copying machine of FIG.

[Explanation of symbols]

14: original placing table, 8: original discharging table, 9 to 13: original sheet conveying means, 1: reading reference member, 17 to 19: reading means, Ps: original sheet, 2a: step forming member (contact preventing means) 4a: paper feeding means, 3: background portion forming member, 8:
Frame, 5: support member, 3a: spacer, 7: pressing force applying member.

Claims (10)

[Claims] 1. An original placing table on which original sheets are placed, an original ejecting stage for ejecting original sheets, and an original sheet conveying means for conveying the original sheets one by one from the original placing table to the original ejecting table. A transparent or semi-transparent reading reference member is provided along the original feeding path, and is provided on the opposite side of the reading reference member from the original feeding path, and is read on an original sheet through the reading reference member. The reading light or the reflected light in an original reading device which irradiates light and reads an image of the original based on the light reflected by the original, and reads the original image while the original is conveyed. An original reading device comprising contact preventing means for preventing an original sheet from coming into contact with a portion of a reading reference member through which a sheet passes. 2. The contact preventing member is a step forming member having a predetermined thickness, and is arranged on the side surface of the reading reference member on the side of the sheet conveying path. Document reader. 3. The step forming member is arranged upstream of the reading surface of the reading reference member optically read by the reading means in the conveying direction of the original sheet. The document reading device described. 4. The step forming member is configured such that a side surface thereof on the sheet conveying path side has a friction coefficient equal to or lower than a side surface of the reading reference member on the sheet conveying path side. 2. The document reading device described in 2. 5. The step formed by the step forming member and the reading reference member has a size of 0.3 mm or more and 0.7 mm.
And the distance from the focus position of the reading means is 2 or less.
mm or more and 5 mm or less, 3.
The document reading device described. 6. The document reading device according to claim 1, further comprising a sheet feeding unit that applies a conveying force to the document sheet, at a position facing the reading reference member. 7. The sheet feeding means is arranged in pressure contact with the step forming member, and the side surface of the step forming member on the sheet conveyance path side is configured to have a lower friction coefficient than that of the sheet feeding means. The document reading device according to claim 6. 8. A position facing a reading reference member,
8. The document reading apparatus according to claim 7, wherein a background portion forming member is arranged at a position downstream of the paper feeding unit in the sheet conveying direction with a distance from the reading reference member. 9. A sheet having a frame arranged to be openable and closable with respect to a reading reference member, a sheet feeding unit and a background portion forming member being provided on the frame, and the sheet feeding unit and the background with respect to the reading reference member. 9. The document reading device according to claim 8, wherein the section forming member is configured to open and close, wherein the sheet feeding unit and the background section forming member are provided with a supporting member swingably arranged with respect to the frame. A document reading device characterized in that the document reading device is arranged on the frame. 10. A spacer is disposed on the side surface of the background portion forming member on the side of the sheet conveyance path, and a pressing force applying member for pressing the background portion forming member to the reading reference member side is provided. Item 9. The document reading device according to item 9.