JPH10190909A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of parts and assembly man-hours and to dissolve the focus divergence of read images at a low cost by integrally molding a first frame body and a second frame body and deciding the positional relation of a carrying means held by the first frame body and a holding part, housed in the second frame body by one frame body. SOLUTION: A frame as the first frame body supports a paper feed roller 1 and a paper discharge roller 3 and is integrally provided with a contact image sensor housing part D as the second frame body for which the holding part for stipulating the respective position relation of a photosensor 10b, a 'Selfoc(R)' lens 10c and a cover glass 10d is integrally molded simultaneously. Thus, since the paper feed roller 1, the paper discharge roller 3 and the cover glass 10d are positioned only by a frame 7, the focus divergence by the floating of an original is prevented. Further, since a contact image sensor unit is easily constituted merely by successively fitting the parts to the holding part of the contact image sensor housing part D, the assembly man-hours is reduced and the cost is lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device.

[0002]

2. Description of the Related Art A schematic configuration of a conventional image reading apparatus is shown in FIG.

In FIG. 5, reference numeral 101 denotes a document at a reading position A.
Roller 102 for feeding paper to the paper feed roller 102;
03 is a discharge roller for discharging the read original, 104
Denotes a discharge pinch roller, 105 denotes an upper document guide that forms the upper part of the document conveyance path, 106 denotes a lower document guide that forms a lower part of the document conveyance path, 107 denotes a paper feed roller 101, a paper discharge roller 103, and the like. Reference numeral 108 denotes a document holder for preventing the document from floating at the reading position A, and reference numeral 109 denotes a contact image sensor unit 110 to be described later.
Reference numeral 110 denotes a mounting image sensor unit for reading image information of a document.

A contact image sensor unit 110
Is a light source 110a that illuminates the reading surface of the document, an optical sensor 110b that converts image information of the document into an electric signal, and a light source 11
Image information of the document illuminated by the light sensor 110a.
b, a cover glass 110d for defining a document position at the reading position A, a light source 110a and an optical sensor 110
sensor chassis 110e for positioning and fixing b and the selfoc lens 110c, and a guide mylar 110 for smoothly guiding the document from the lower document guide 106 to the reading position A.
f, a sensor frame 110g accommodating a light source 110a, an optical sensor 110b, a selfoc lens 110c, a cover glass 110d, and a sensor chassis 110e.

[0005]

However, in the above-mentioned prior art, the contact image sensor unit is mounted on the frame by the mounting bracket, and thus has the following problems. First, the number of components and the number of assembling steps as a contact image sensor unit are large, which has caused a cost increase.

The document passing surface of the cover glass that defines the position of the document prevents the document from being blurred due to the floating of the document when the document is transported in a state where the document is sandwiched between the feed roller and the discharge roller. For this purpose, as shown in FIG. 5, it is preferable that the line B is the same as the line B connecting the outer circumferences of the paper feed roller and the paper discharge roller, or protrudes beyond the line B. However, in the conventional configuration, the positioning of the feed roller and the discharge roller and the cover glass is performed by the frame,
The error is large because it is determined via the mounting bracket, the sensor frame, and the sensor chassis, and the cover glass may be located on the opposite side of the document press from the line B, which causes defocus of the read image. . Conventionally, in order to prevent this, it has been necessary to perform strictness in dimensional accuracy of each component or to perform positioning by providing an adjustment mechanism, etc., which has caused a significant cost increase.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. It is an object of the present invention to reduce the number of components and the number of assembling steps, and to reduce the defocus of a read image at low cost. A reading device is provided.

[0008]

In order to achieve the above object, according to the present invention, there is provided a conveying means for conveying a document, a first frame for holding the conveying means, a light source for illuminating the document. An image forming means for forming an image of a document, a photoelectric conversion unit for converting image information guided to the image forming means into an electric signal, and a positional relationship between the light source, the image forming means and the photoelectric conversion unit. A first frame and a second frame in an image reading apparatus having a holding unit for defining the light source, the image forming means, the photoelectric conversion unit, and a second frame for housing the holding unit; Are integrated, and the transporting means held by the first frame,
The positional relationship with the holding portion housed in the second frame is determined by one frame.

Therefore, the transporting means and the holding section are positioned by one frame, that is, the positional relationship between the transporting means and each component whose positional relationship is defined in the holding section is one through the holding section. Is determined by one frame.

[0010] The holding portion is preferably formed integrally with the second frame.

Therefore, the positional relationship between the transporting means and each component whose positional relationship is defined in the holding portion is determined only by one frame.

The image forming means is preferably positioned and fixed by a holding portion near both ends in a direction orthogonal to the document conveying direction by the conveying means.

Therefore, the position of the image forming means is determined only at the positions near both ends of the image forming means in the holding section, and is not affected by other parts.

The photoelectric conversion section is preferably positioned and fixed by the holding section near both ends in a direction perpendicular to the direction of document transport by the transport means.

Therefore, the position of the photoelectric conversion unit is determined only in the vicinity of both ends of the photoelectric conversion unit in the holding unit, and is not affected by other parts.

The holding section is preferably positioned and fixed by a second frame near both ends in a direction perpendicular to the direction of document transport by the transport means.

Therefore, the position of the holding member is determined only by the frame portions near both ends of the holding member in the frame, and is not affected by other portions.

It is preferable that the image forming apparatus includes a defining means for defining a distance between the image forming means and the original reading position, and the defining means defines a light source and a positional relationship between the image forming means and the photoelectric conversion section by a holding portion. Thus, the distance between the image forming unit and the document reading position is determined, and the holding unit defines the document reading position defined by the defining unit, the light source, and the positional relationship between the light source and the image forming unit and the photoelectric conversion unit. You.

The defining means is preferably a transparent member interposed between the image forming means and the document reading position.

Therefore, the distance between the image forming means and the document reading position is determined by the thickness of the transparent member by bringing the image forming means into contact with or near the one end face of the transparent member and the document reading position on the opposite end face side. .

The image forming means is preferably formed integrally with the holding section.

Thus, the image forming means is integrated with the holding section.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 and 2 show a first embodiment of the present invention.

FIG. 1 is a schematic sectional view of a main part of an image reading apparatus according to a first embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a paper feed roller for transporting a document to a reading position A serving as a document reading position, reference numeral 2 denotes a paper feed pinch roller, reference numeral 3 denotes a discharge roller for discharging the read document, and reference numeral 4 denotes a paper discharge. A pinch roller, 5 is an upper document guide forming the upper part of the document conveying path, 6 is a conveying means for conveying the document by the lower document guide forming the lower part of the document conveying path, and 7 is a first conveying means. A frame 8 of the image reading apparatus as a frame, a document holder 8 for preventing the document from floating at the reading position A, a light source 10a for illuminating the reading surface of the document, and a photoelectric conversion device 10b for converting image information of the document into an electric signal. The optical sensor 10c as a unit is a selfoc lens (trade name: Nippon Sheet Glass) as an image forming means for imaging the image information of the document illuminated by the light source 10a on the optical sensor 10b. A cover glass as a defining means and the transparent member defining the original position at position A.

The frame 7 supports the paper feed roller 1 and the paper discharge roller 3 and, at the same time, in the vicinity of the reading position A, determines the positional relationship among the light source 10a, the optical sensor 10b, the selfoc lens 10c, and the cover glass 10d. It has a contact image sensor storage section D as a second frame body in which a prescribed holding section is integrally formed.

The reading operation will be briefly described in the above configuration. The document is conveyed to the reading position A by being sandwiched between the sheet feeding roller 1 and the sheet feeding pinch roller 2. At the reading position A, the original is brought into close contact with the cover glass 10 d by the original holder 8. Then, while the image information of the document is read line by line, the document is conveyed to the discharge roller 3 and the discharge pinch roller 4. Finally, the read original is discharged by the discharge roller 3 and the discharge pinch roller 4.

Next, the contact image sensor storage D will be described.

When the frame 7 is located near the reading position A, the light source 10a, the optical sensor 10b, the selfoc lens 10c, the cover glass 10
By storing d, a function of constituting a contact image sensor unit is provided. That is, the contact image sensor unit can be easily assembled simply by sequentially fitting the optical sensor 10b, the selfoc lens 10c, the light source 10a, and the cover glass 10d in the holding portion of the contact image sensor storage D. At this time, selfoc lens 1
A cover glass 10d having a thickness corresponding to the focal length of 0c is
Fix it so that it abuts the Selfoc lens 10c,
In addition, by setting the distance between the SELFOC lens 10c and the optical sensor 10b in the contact image sensor housing D to be the same as the focal length of the SELFOC lens 10c, focusing can be performed without adjusting the focal length. Can be. The optical sensor 10b and the cover glass 10
As a fixing method of d, a method of press-fitting and adhering to the holding portion of the contact image sensor storage portion D, a method of pressing with a plate spring or a snap fit (in the case of the cover glass 10d, outside the document passing range), and the like can be considered. From the viewpoint of reducing the number of parts and the number of assembly steps, press-fitting is desirable. Also, the cover glass 10d is
A member such as resin instead of glass may be used as long as the document is not easily damaged by paper passing and sufficiently transmits light.

As described above, since the contact image sensor unit is integrally formed with the frame 7, there are the following advantages as compared with the related art. Paper feed roller 1, paper discharge roller 3, and cover glass 10d
Is positioned only by the frame 7, so that the document passing surface of the cover glass 10d is the same as the line B connecting the outer periphery of the paper feed roller 1 and the paper discharge roller 3, or protrudes further toward the document presser 8 side. It is possible to accurately arrange the original at the position, and even when the original is sandwiched between the paper feed roller 1 and the discharge roller 3 and the original is conveyed in a taut state, the blurring of the original due to the floating of the original can be prevented. The number of components can be reduced, and the cost can be reduced. The optical sensor 1 is attached to the holding section of the contact image sensor storage section D.
0b, the selfoc lens 10c, the light source 10a, and the cover glass 10d can be easily configured by simply inserting the contact image sensor unit in sequence, thereby reducing the number of assembly steps,
Cost can be reduced.

FIG. 2 is a cross-sectional view of a main part of the image sensor storage section D in a direction perpendicular to the direction of document transport.

In FIG. 2, the optical sensor 10b and the selfoc lens 10c are positioned and fixed in the vicinity of both ends (part E shown in FIG. 2) in the direction (longitudinal direction) perpendicular to the document conveying direction. It is possible to prevent the frame 7 in the direction perpendicular to the document conveying direction from being affected by a focus shift or the like due to a warp during forming (warp in directions F and G shown in FIG. 2).

Further, by forming the SELFOC lens 10c integrally with the frame 7, the number of components and the number of assembly steps can be further reduced, and the cost can be further reduced. (Second Embodiment) FIGS. 3 and 4 show a second embodiment of the present invention. In the first embodiment, the holding portion is formed integrally with the frame.
In this embodiment, the holding portion is a member independent of the frame.

FIG. 3 is a schematic sectional view of a main part of an image reading apparatus according to a second embodiment of the present invention.

In FIG. 3, reference numeral 21 denotes a paper feed roller for transporting the original to the reading position A, 22 a paper feed pinch roller, 23 a paper output roller for discharging the read original, 24 a paper output pinch roller, and 25 a paper feed pinch roller. An upper document guide forming the upper part of the document conveying path, 26 constitutes a conveying means for conveying the document by means of the lower document guide forming the lower part of the document conveying path, and 27 designates an image as a first frame. A frame 28 of the reading device, a document holder 28 for preventing the document from floating at the reading position A, and a light source 20a for illuminating the reading surface of the document,
Reference numeral 0b denotes an optical sensor as a photoelectric conversion unit that converts image information of the document into an electric signal. Reference numeral 20c denotes a selfoc lens (product) that forms image information of the document illuminated by the light source 20a on the optical sensor 20b. Name: Nippon Sheet Glass),
20d is a defining means for defining the document position at the reading position A and a cover glass as a transparent member.
Light source 20a, optical sensor 20b and selfoc lens 20
This is a sensor chassis as a holding unit for positioning the cover c and the cover glass 20d. The frame 27 supports the paper feed roller 21 and the paper discharge roller 23, and at the same time, near the reading position A, the light source 20a, the optical sensor 20b,
A self-contact lens 20c, a cover glass 20d, and a contact image sensor storage portion H as a second frame for storing the sensor chassis 20e are integrally provided.

The reading operation will be briefly described in the above configuration. The original is fed by the feed roller 21 and the feed pinch roller 2.
2 and is transported to the reading position A. Reading position A
The original is moved to the cover glass 20 by the original holder 28.
d. Then, while the image information of the document is read line by line, the document is conveyed to the discharge roller 23 and the discharge pinch roller 24. Finally, the read original is discharged by the discharge roller 23 and the discharge pinch roller 24.

Next, the contact image sensor storage section H will be described.

When the frame 27 is located near the reading position A, the light source 20a, the optical sensor 20b, the selfoc lens 20c, the cover glass 2
0d, a function of constituting a contact image sensor unit by housing the sensor chassis 20e. That is, the optical image sensor 20b, the sensor chassis 20e, the selfoc lens 20c, the light source 20a, and the cover glass 20d are simply inserted into the optical image sensor housing section H in order, so that the optical image sensor unit can be easily assembled. At this time, the cover glass 20d is fixed to the selfoc lens 20c so that the cover glass 20d abuts on the selfoc lens 20c.
Between the selfoc lens 20c and the sensor chassis 2
0e and the optical sensor 20a are fixed in a sandwiched state.
Here, the thickness of the cover glass 20d and the sensor chassis 2
0e, from the selfoc lens 20c to the optical sensor 20a.
If the dimensions up to are set in advance, it is possible to adjust the focus without adjusting the focal length. The fixing method of the cover glass 20d is as follows.
For example, press-fitting, bonding, or pressing with a leaf spring or snap fit outside the range of document passing may be considered, but press-fitting is desirable from the viewpoint of reducing the number of parts and the number of assembly steps. The cover glass 20d may be made of a material other than glass, such as resin, as long as the cover glass 20d is not easily damaged by the passage of the original and sufficiently transmits light.

As described above, since the contact image sensor unit is integrally formed with the frame 27, there are the following advantages as compared with the related art. Paper feed roller 21, paper discharge roller 23, and cover glass 2
0d is positioned by the frame 27 with the sensor chassis 20e interposed therebetween.
Is the same as the line B connecting the outer circumferences of the paper feed roller 21 and the paper discharge roller 23, or more than the line B.
The document can be accurately arranged at a position protruding to the side, and even when the document is sandwiched between the feed roller 21 and the discharge roller 23 and the document is conveyed in a taut state, out-of-focus due to floating of the document is prevented. be able to. The number of components can be reduced, and the cost can be reduced. The contact image sensor unit can be easily configured simply by sequentially inserting the optical sensor 20b, the sensor chassis 20e, the selfoc lens 20c, the light source 20a, and the cover glass 20d into the contact image sensor storage section H, so that the number of assembly steps is reduced. Cost can be reduced. Since the optical image sensor 20b, the sensor chassis 20e, the selfoc lens 20c, the light source 20a, and the cover glass 20d are sequentially inserted into the image sensor housing portion H from above, the image sensor unit can be easily formed, and is a holding member. Compared to a case where the second frame has a holding part integrally formed without independently having the sensor chassis 20e, the structure of the second frame is simpler, so that assembling workability and maintainability are improved. Can be done.

As shown in FIG. 4, the optical sensor 20b,
Selfoc lens 20c and sensor chassis 20e
By configuring so as to be positioned and fixed in the vicinity of both ends (portion I shown in FIG. 4) in the direction (longitudinal direction) perpendicular to the document transport direction, the warpage of the frame 27 in the direction perpendicular to the document transport direction during molding ( It is possible to prevent the influence of defocus or the like due to the warpage in the J and K directions shown in FIG.

Further, by forming the SELFOC lens 20c integrally with the sensor chassis 20e, the number of components and the number of assembly steps can be further reduced, and the cost can be further reduced.

[0042]

According to the present invention, the first frame and the second frame are integrated with each other and have the above-described structure and operation. Since the positional relationship between the holding unit and the holding unit housed in the second frame is determined by one frame, the transporting unit and the holding unit are positioned by one frame, that is, the transporting unit and the holding unit. The positional relationship with each component whose positional relationship is defined in the part can be determined with only one frame via the holding part, so that it can be arranged with high accuracy, and the number of parts and the number of assembly steps And reduce costs.

Since the holding section is integrally formed with the second frame, the positional relationship between the conveying means and each component whose positional relationship is defined in the holding section is directly determined by one frame. Therefore, the arrangement can be performed with higher accuracy, and the number of parts and the number of assembling steps can be reduced, and the cost can be reduced.

The image forming means is positioned and fixed by the holding portion near both ends in the direction orthogonal to the direction of document conveyance by the conveying means, so that the position of the image forming means can be adjusted at both ends of the image forming means in the holding portion. Is determined only in the part near the part,
Since the other parts are not affected, even if the other parts are deformed or distorted due to molding or the like, the imaging means is not affected by the deformation or distortion, and the influence does not cause a defocus or the like. .

The photoelectric conversion section is positioned and fixed by the holding section near both ends in a direction orthogonal to the document conveying direction by the conveying means, so that the position of the photoelectric conversion section is the position of the photoelectric conversion section in the holding section. Since it is determined only at the portions near both ends and is not affected by the other portions, even if the other portions are deformed or distorted due to molding or the like, the photoelectric conversion portion is not affected.

The holding section is positioned and fixed by the second frame near both ends in a direction perpendicular to the direction of document conveyance by the conveyance means, so that the position of the holding member is set at both ends of the holding member in the frame. Since it is determined only by the frame portion in the vicinity of the portion and is not affected by other portions, even if other portions are deformed or distorted due to molding or the like, the holding portion is not affected by the deformation or distortion.

The image forming apparatus has a defining means for defining the distance between the image forming means and the document reading position. The defining means defines a light source by a holding unit, and a positional relationship between the image forming means and the photoelectric conversion unit. If the document reading position is adjusted to the focal length of the image forming means, there is no need to adjust the focal length, and the position of the transport means and the document reading position are determined with high accuracy. Since the sheet is conveyed to the reading position, out-of-focus can be prevented.

Since the defining means is a transparent member interposed between the image forming means and the document reading position, the image forming means is provided on one end surface side of the transparent member and the document reading position is brought into contact with or near the opposite end surface side. By doing so, if the thickness of the transparent member is adjusted to the focal length of the imaging means, there is no need to adjust the focal length.

Since the image forming means is formed integrally with the holding member, the image forming means is integrated with the frame, so that the number of parts and the number of assembling steps can be reduced, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a main part of an image reading apparatus according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a main part of the first embodiment of the present invention.

FIG. 3 is a schematic sectional view of a main part of an image reading apparatus according to a second embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a main part according to a second embodiment of the present invention.

FIG. 5 is a schematic sectional view of a main part of a conventional image reading apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Paper feed roller 3 Paper discharge roller 7 Frame 10a Light source 10b Optical sensor 10c Selfoc lens 10d Cover glass 20a Light source 20b Optical sensor 20c Selfoc lens 20d Cover glass 20e Sensor chassis 21 Paper feed roller -Laser 23 Discharge roller 27 Frame A Reading position D Contact image sensor storage H Contact image sensor storage

Claims (8)

[Claims] 1. A conveying means for conveying a document, a first frame for holding the conveying means, a light source for illuminating the document, an image forming means for forming an image of the document, and A photoelectric conversion unit that converts the guided image information into an electric signal; and a holding unit that defines a positional relationship between the light source, the imaging unit, and the photoelectric conversion unit, and the light source, the imaging unit, and the photoelectric conversion unit. An image reading apparatus having a second frame for housing a conversion unit and the holding unit, wherein the first frame and the second frame are integrated, and the conveyance held by the first frame is performed. An image reading apparatus, wherein the positional relationship between the means and the holding unit housed in the second frame is determined by one frame. 2. The image reading apparatus according to claim 1, wherein said holding portion is formed integrally with said second frame. 3. The image reading apparatus according to claim 1, wherein the image forming unit is positioned and fixed by the holding unit near both ends in a direction orthogonal to a document conveying direction by the conveying unit. apparatus. 4. The apparatus according to claim 1, wherein said photoelectric conversion unit is positioned and fixed by said holding unit near both ends in a direction orthogonal to a document transport direction by said transport unit.
Or the image reading device according to 3. 5. The apparatus according to claim 1, wherein said holding section is positioned and fixed by a second frame near both ends in a direction orthogonal to a document conveying direction by said conveying means.
Or the image reading device according to 4. 6. An image forming apparatus, comprising: defining means for defining a distance between the image forming means and a document reading position, wherein the defining means determines the positional relationship between the light source, the image forming means and the photoelectric conversion unit by the holding unit. 6. The image reading apparatus according to claim 1, wherein the image reading apparatus is defined. 7. An image reading apparatus according to claim 6, wherein said defining means is a transparent member interposed between said image forming means and said document reading position. 8. An image reading apparatus according to claim 1, wherein said image forming means is formed integrally with said holding portion.