JPH1169044A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the failures of the blurs of images and the stripes of the images by arranging first and second positioning means so as to position an original read position defined by a first read means and the first positioning means and the original read position defined by a second read means and the second positioning means on the almost same plane. SOLUTION: The original read position 29a of a transparent member by a first contact type image sensor 29 and the original read position 33a of the transparent member in a second contact type image sensor 33 are disposed on the almost same plane A. Also, at the respective original read positions 29a and 33a, first and second pressurizing plates 30 and 34 are biased to the transparent member by a spring. By arranging the original read positions 29a and 33a on the almost same plane in such a manner, an original is brought into close contact with both of the first and second contact type image sensors 29a and 33a by a slight biasing force. By pushing up the tip of the original by the pressurizing plates 30 and 34, a jam is evaded.

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 such as a copying machine, a facsimile, and an image scanner.

[0002]

2. Description of the Related Art An example of a conventional image reading apparatus is shown in FIG. 5 (first conventional example). In the figure, reference numeral 71 denotes a first reading unit using a reduction optical system having a high focus sensitivity for reading one surface of a document, and 72 denotes first reading means 71 for reading the other surface of the document. This is a second reading unit configured similarly. The first reading unit 71 and the second reading unit 72 include transparent members 91 and 92, mirrors 101 and 102, imaging lenses 103 and 104, optical sensors 105 and 106, and a light source 1, respectively.
07,108. Reference numeral 81 denotes a plurality of transport roller pairs for transporting the original.

When the original conveyed by the pair of conveying rollers 81 reaches the original reading position 91a of the first reading section 71, the original is irradiated by the light source 107. The reflected light is transmitted to the optical sensor 1 by the mirror 101 and the imaging lens 103.
The image is formed on the original 05 and the image on the original is read. Next, when the document is conveyed to the document reading position 91b of the second reading section 72, reading is performed in the same manner as in the first reading 71. Here, the document conveying path 79 is substantially horizontal and has a predetermined interval.

Next, another example of a conventional image reading apparatus is shown in FIG. 6 (second conventional example). In the figure, reference numeral 73 denotes a document 1
A first reading unit 74 using a reduction optical system having a high focus sensitivity for reading one side is a second reading unit configured similarly to the first reading unit 73 for reading the other side of the document. The first reading unit 73 and the second reading unit 74 include transparent members 93 and 94, light sources 109 and 112, rod lenses 110 and 113, and optical sensors 111 and 114, respectively.

[0005] Also, 75 and 77 are the first and second, respectively.
Original reading positions 93a, 94a of the original reading units 73, 74
, First and second pressing plates urged by first and second springs 76 and 78 so as to bring the original into close contact with the transparent members 93 and 94, 79 is an original conveying path through which the original passes, and 82 is There are a plurality of transport roller pairs for transporting the original.
In this conventional example, similarly to the above-described apparatus, the document conveying path 73
Are arranged substantially horizontally and at predetermined intervals, but the first pressing plate 75 and the second pressing plate 77 move one surface and the other surface of the document to the document reading position 93a and the document reading position 94a, respectively. Are pressed against the transparent members 93 and 94, so that the focus is not shifted.

FIG. 7 shows another conventional example (third conventional example). The configuration of the apparatus shown in FIG. 11 is basically the same as that of the conventional example shown in FIG. 6, except that the document feed path 79 is configured to be non-linear in order to reduce the size of the apparatus. ing.

[0007]

However, the first aspect
In the conventional example, since the original conveying path has a predetermined interval, when the close contact type image sensor, which is an equal-magnification optical system, is used, the focus sensitivity is low. 2
Attempting to focus on either one of the reading means 72 causes the inconvenience of moving away from the other focus and blurring the image to be read.

In the second conventional example, the original is moved up and down in the transport path by the first pressing plate 75 and the second pressing plate 77. Therefore, in order for the first reading unit 73 and the second reading unit 74 to focus on even a thick and thick original, the first spring 76 and the second spring 78 are required.
Therefore, the urging force for urging the first pressing plate and the second pressing plate 77 needs to be increased to some extent. However, if the biasing force is too strong, jamming may occur when reading a thin original with a weak waist, although the problem of defocus is solved.

In the third conventional example, when reading a thick original having a strong stiffness, an image defect may occur due to a shock when the original is curved. Further, there is a problem in that the original is rubbed on the wall surface in the original conveying path 79 to generate powder, which is read and streaked into the read image.

Furthermore, in the second and third prior art examples, the first spring 76 and the second spring 78 must have different configurations, which causes assembly errors and increases costs. In other words, the urging force of the pressing member for securely pressing the original from the thick original to the original with the low rigidity to the original reading position of the transparent member, and conveying the original without jamming is in a very limited range, and Must be identical. However, in order to realize this, the first spring 76 applies the urging force applied to the first pressing member 75 by the weight of the original and the weight of the pressing member due to the original conveying path being in the horizontal direction and the second pressing force. It is necessary to change the urging force applied to the second pressing member 77 by the spring 78, and adjustment is difficult.

In the second and third conventional examples, the leading edge of the document rubs against the bottom surface of the document carrying path 79 by its own weight, so that if the bottom surface is not smooth or foreign matter is mixed, There is a problem that the tip is caught and skewed.

Further, a wall surface in the document conveying path 79, the first
The original is rubbed at the corners of the reading unit 73 and the second reading unit 74, and powder is generated.

[0013]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. In the image reading apparatus according to the first aspect, a conveying means for conveying a document, and a conveying means for conveying the document. First reading means for reading one surface of the document, first positioning means for positioning the document facing the first reading means, and the other of the document conveyed by the conveyance means. A second reading unit that reads a surface; and a second positioning unit that positions the document in opposition to the second reading unit. The second positioning unit is defined by the first reading unit and the first positioning unit. The first and second reading means and the first and second reading means are located such that the original reading position and the document reading position defined by the second reading means and the second positioning means are substantially on the same plane. 2 positioning means Characterized in that arranged, respectively.

According to a second aspect of the present invention, in the first aspect, the first and second reading means include an optical sensor for converting an image on the document into an image signal. And

According to a third aspect of the present invention, in the image reading apparatus according to the second aspect, the first and second reading means further include a lens for forming an image of light reflected from the surface of the document to be read. It is characterized by the following.

According to a fourth aspect of the present invention, in the image reading apparatus of the third aspect, the first and second reading means further include a light source for illuminating a surface to be read of the document. .

According to a fifth aspect of the present invention, in the image reading apparatus according to the fourth aspect, the first and second reading means further include a transparent member which abuts on the original to define a surface to be read of the original. It is characterized by having.

In the image reading apparatus according to a sixth aspect, in the fifth aspect, the first and second reading means further house and hold the optical sensor, the lens, the light source, and the transparent member. It has a housing.

According to a seventh aspect of the present invention, in the image reading apparatus according to any one of the first to sixth aspects, wherein
And the second positioning means positions the document by a spring.

The image reading apparatus according to the present invention is characterized in that, in any one of the first to seventh aspects, the conveying means conveys the original by a roller.

According to a ninth aspect of the present invention, in the image reading apparatus according to the eighth aspect, the transporting means comprises a plurality of pairs of rollers for nipping and rotating the original.

According to a tenth aspect of the present invention, in the ninth aspect, the plurality of roller pairs are arranged at least before and after the first and second reading means.

[0023] In the image reading apparatus according to the eleventh aspect, in the tenth aspect, the nipping position at which the document is nipped by the plurality of roller pairs is located substantially on the same plane as the reading position. A plurality of roller pairs are arranged.

Further, in the image reading apparatus according to the twelfth aspect, a conveying means for conveying the original in a substantially vertical direction, and a first means for reading one surface of the original conveyed by the conveying means.
And second reading means for reading the other side of the document conveyed by the conveying means, wherein the first reading means
The first reading means and the second reading means are arranged so as to be displaced in a substantially vertical direction so that the original reading position by the reading means and the original reading position by the second reading means are different.

According to a thirteenth aspect of the present invention, in the twelfth aspect, the document reading position by the first reading means and the document reading position by the second reading means are located on substantially the same plane. The first reading means and the second reading means are arranged as described above.

In the image reading apparatus according to the present invention, the first and second image reading apparatuses may be configured as described above.
Is characterized by having an optical sensor for converting an image on the document into an image signal.

According to a fifteenth aspect of the present invention, in the image reading apparatus according to the fifteenth aspect, the first and second reading means further include a lens for forming an image of reflected light from the surface to be read of the document. It is characterized by the following.

[0028] In the image reading apparatus according to a sixteenth aspect, in the fifteenth aspect, the first and second reading means further include a light source for illuminating the read surface of the document. .

In the image reading apparatus according to a seventeenth aspect, in the sixteenth aspect, the first and second reading means further include a transparent member that abuts on the original and defines a surface to be read of the original. It is characterized by having.

[0030] In the image reading apparatus according to the eighteenth aspect, in the seventeenth aspect, the first and second reading means further house and hold the optical sensor, the lens, the light source, and the transparent member. It has a housing.

[0031] In the image reading apparatus according to the nineteenth aspect, in any one of the twelfth to eighteenth aspects, the transporting means transports the original by a roller.

According to a twentieth aspect of the present invention, in the nineteenth aspect, the transporting means comprises a plurality of pairs of rollers for nipping and rotating the original.

According to a twenty-first aspect of the present invention, in the twentieth aspect, the plurality of roller pairs are arranged at least before and after the first and second reading means.

Further, in the image reading apparatus according to the present invention, in the image reading apparatus according to the present invention, the nipping position at which the document is nipped by the plurality of roller pairs is located substantially on the same plane as the reading position. A plurality of rollers are arranged.

According to a twenty-third aspect of the present invention, there is provided the image reading apparatus according to any one of the twelfth to twenty-second aspects, further comprising: And second positioning means for positioning the document in opposition to the second reading means.

In the image reading apparatus according to the twenty-fourth aspect, the document reading position defined by the first reading means and the first positioning means, and the second reading means and the second positioning means are provided. Wherein the first and second reading means and the first and second positioning means are respectively arranged such that the document reading position defined by the formula (1) is located on substantially the same plane.

[0037] In the image reading apparatus according to the twenty-fifth aspect, the first and second parts may be arranged according to the twenty-third or the twenty-fourth aspects.
Is characterized in that the original is positioned by a spring.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG.
1 is a diagram showing an example in which an image reading apparatus of the present invention is applied to a facsimile apparatus 1. The facsimile machine 1
A reading unit 11 for reading a document, a recording unit 12 for recording a received image, an operation unit 13 for a user to make various settings for transmission, and a control unit for controlling transmission and reception (Not shown).

FIG. 2 shows the facsimile apparatus 1 shown in FIG.
3 is a main cross-sectional view of the reading unit 11 of FIG. In the drawing, a document table on which a document S is placed with its front side up, a regulating plate 22 that slides in accordance with the width of the document and guides the document sheet so as not to skew when the document is conveyed, and 23 is a document table 21 A document presence sensor for detecting whether or not the document S is set on the sheet; a pick-up roller 24 for feeding the document set by the user to a separation unit to be described later; and a plurality of sheets 25 fed by the pickup roller 24 Among the originals, the uppermost original is fed into the apparatus. A separation feed roller 26 is used to feed the uppermost original when the separation feed roller 25 feeds the uppermost original. It is a separation reverse rotation roller which rotates in the direction opposite to the feeding direction so as not to be fed.

Reference numeral 27a denotes a first transport roller which holds the separated and fed original S together with the rollers 27b, and transports the original at a predetermined transport speed. Reference numeral 28 denotes a first original roller for adjusting the reading timing. , A first contact image sensor (first reading means) for reading image information on the back surface of the document, and a reference numeral 30 for the first contact image sensor 29. A first document pressing plate (first positioning means) urged by a first spring 31 so as to be in close contact with the reading surface, 32a
And 32c, and a second transport roller for transporting the original at the same speed as the first transport roller 27a.

Reference numeral 33 denotes a second contact image sensor (second reading means) for reading image information on the surface of the document, and reference numeral 34 denotes a second contact image sensor for bringing the document into close contact with the reading surface of the second contact image sensor 33. A second document pressing plate (second positioning means) biased by a second spring 35, 36a
6B, a third transport roller for transporting a document at the same speed as the first transport roller 27a and the second transport roller 32a.

Reference numerals 32c and 36c denote second transport rollers 32.
a and a document whose image is read by being urged by the third transport roller 36a, is transferred to the second transport roller 32.
a, a roller for holding the original together with the roller 37b and discharging it outside the apparatus;
Reference numeral 38 denotes a discharge tray for stacking the discharged originals;
Is a document transport path that forms a path through which the document is transported.
Here, the first transport roller 27a, the roller 27b, the second transport roller 32a, the roller 32b, and the third transport roller 36.
The conveying means is constituted by a and the roller 36b.

FIG. 3 is a sectional view of the first contact image sensor and the second contact image sensor 33. As shown in FIG. In the figure, reference numeral 51 denotes a light source for illuminating a surface to be read of a document;
A lens 53 for imaging reflected light from the surface of the original to be read;
Is a light sensor that converts an optical image formed by the lens 52 into an electric signal, 54 is a transparent member arranged so that the read surface of the document is adjusted to the focal position of the lens 52 when the document is brought into close contact, and 55 is This is a sensor housing that houses and holds the light source 51, the lens 52, the optical sensor 53, and the transparent member 54.

Next, the reading operation of this embodiment by the image reading apparatus will be described with reference to the flowchart of FIG.

S1: The user sets the document S on the document table 21, and slides the regulating plate 22 in accordance with the width of the document.

S2: The document presence sensor 23 detects a document.

S3: The user inputs necessary information (for example, a transmission destination telephone number) from the operation unit 13 and starts reading.
Let it go.

S4: When driven by a drive source (not shown), the pick-up roller 24 feeds the original, and only one uppermost original is separated by the separation feeding roller 25 and the separation reverse roller 26. Will be fed.

S5: The fed document S is conveyed by the first conveyance roller 27a and the roller 27b, and the leading edge of the document S is detected by the document edge sensor 28.

S6: After the leading edge of the original S is detected, the timing is adjusted to a position where the leading edge of the original slightly exceeds the reading position of the first contact image sensor 29, and the image information on the back surface of the original S is read. Is started.

S7: The conveyance is further advanced, and the reading of the image information on the front surface of the document is started at a timing where the leading end of the document slightly exceeds the reading position of the second close contact type image sensor 33.

S8: After the trailing edge of the document S is detected by the document edge sensor 28, the timing of the document S is adjusted just before the trailing edge of the document S exceeds the reading position of the 41st contact image sensor 29. The reading of the image information on the back side of is ended.

S9: The conveyance is further advanced, and the reading of the image information on the front side of the document is completed at a timing slightly before the rear end of the document slightly exceeds the reading position of the second contact image sensor 33.

S10: Documents are discharged and stacked on a discharge tray 38 by the discharge rollers 37a and rollers 37b.

S11: If the document presence sensor 23 is still detecting the document, the operations of S4 to S10 are repeated.
When the document presence sensor 23 stops detecting the document, it is determined that all the set documents have been read, and the reading operation ends.

In the image reading apparatus of the present embodiment as described above, the original reading position 29a of the transparent member 54 in the first contact type image sensor 29 and the second contact type image sensor.
Original reading position 33 of transparent member 54 in sensor 33
a is disposed on substantially the same plane A, and at each of the document reading positions 29a and 33a, the pressing plate 3 is pressed by a spring.
0 and 34 are urged against the transparent member 54. By arranging the document reading positions 29a and 33a on substantially the same plane in this manner, even when a thick thick document is read, for example, the document is brought into contact with the first contact image sensor 29a and the second contact image sensor 29a. It is possible to closely contact both the mold image sensor 33a with a slight urging force. Further, even when a thin original with a weak waist is read, the urging force of the first spring 31 and the second spring 35 on the first original pressing plate 30 and the second original pressing plate 34 is small. Can be prevented from being jammed when the leading end of the document is pushed up by the first document pressing plate 30 and the second document pressing plate 34.

In the present embodiment, the first contact type image is used.
Original reading position 29 of transparent member 54 in sensor 28
a and the transparent member 5 in the second close contact type image sensor 33
4, the first contact image sensor 29 and the second contact image sensor 33
Are displaced in a substantially vertical direction. Here, the original S
The urging force for bringing the original into close contact with the original reading position 29a and the original reading position 33a must prevent a thin original having a low waist from jamming and even a thick original having a high waist does not float. In the present embodiment, as described above, the first contact image sensor 29 and the second contact image sensor 33 are arranged so as to be shifted in a substantially vertical direction.
Even if the first document pressing plate 30 and the second document pressing plate 34, and the first spring 31 and the second spring 35 are respectively configured by parts having the same specifications, the document is read from the document reading position 29a and the document reading position 33a. It is possible to optimize both the urging forces to be brought into close contact with each other. In addition, the cost can be reduced by using components having the same specifications.

The original reading position 29a of the transparent member 54 in the first contact image sensor 29 and the original reading position 33a of the transparent member 54 in the second contact image sensor 33 are substantially on the same plane A. Placed and plane A
Are arranged in a substantially vertical direction, so that at least in the reading process between the first transport roller 27a and the third transport roller 36a, the leading edge of the original rubs against the wall surface in the original transport path 39. Nothing. Therefore, even when the bottom surface is not smooth or foreign matter is mixed in, the problem that the leading edge of the document is caught and skewed can be avoided.

Further, in the present embodiment, the document holding point B between the first transport roller 27a and the roller 27b,
The document holding point C between the transport rollers 32a and the rollers 32b and the document holding point D between the third transport rollers 36a and the rollers 36b are configured to overlap the plane A described above. At least the first transport roller 27a to the third
The document is transported linearly between the transport rollers 36a. Therefore, the original is rubbed against the wall surface in the original transport path 39 and the corners of the first contact-type image sensor 29 and the second contact-type image sensor, and powder is generated. Problems such as streaks can be avoided.

In this embodiment, the second transport roller 32a and the roller 32b are provided so as to be able to cope with a short document. However, it is apparent that the same effect can be obtained even if these rollers are omitted. It is.

[0061]

As described above, according to the image reading apparatus of the first aspect, the conveying means for conveying the original, and the first means for reading one side of the original conveyed by the conveying means.
Reading means, first positioning means for positioning the document in opposition to the first reading means, second reading means for reading the other side of the document conveyed by the conveyance means, A second positioning means for positioning the document in opposition to a second reading means; a document reading position defined by the first reading means and the first positioning means; and a second reading means. And disposing the first and second reading means and the first and second positioning means so that the document reading position defined by the second positioning means is located on substantially the same plane.
Regardless of the type and thickness of the document, it is possible to perform good image reading without image blur or document jam.

According to a second aspect of the present invention, in the first aspect, the first and second reading means include an optical sensor for converting an image on the document into an image signal. Thus, the effect obtained by the first aspect can be obtained by the image reading apparatus having the optical sensor.

According to a third aspect of the present invention, in the image reading apparatus according to the second aspect, the first and second reading means further include a lens for forming an image of light reflected from the surface of the document to be read. With such a configuration, the effect obtained by the second aspect can be obtained by the image reading apparatus having the lens.

According to a fourth aspect of the present invention, in the image reading apparatus according to the third aspect, the first and second reading means further include a light source for illuminating a surface to be read of the document. Accordingly, the effect obtained by the third aspect can be obtained by the image reading apparatus having the light source.

According to a fifth aspect of the present invention, in the image reading apparatus according to the fourth aspect, the first and second reading means further include a transparent member which abuts on the original to define a surface to be read of the original. The effect obtained by claim 4 can be obtained by the image reading apparatus having the transparent member.

According to a sixth aspect of the present invention, in the image reading apparatus according to the fifth aspect, the first and second reading means further include a housing for housing the optical sensor, the lens, the light source, and the transparent member. By having a structure having a body, in addition to the effect obtained by claim 5, the first
And the respective components of the second reading means can be stored and held.

In the image reading apparatus according to the present invention, the first image reading device may be configured to perform the first method.
Since the second positioning means is configured to position the document by a spring, the document can be reliably positioned by using the spring in addition to the effects obtained in the first to sixth aspects.

In the image reading apparatus according to the present invention, the conveying means is configured to convey the original by a roller in any one of the first to seventh aspects. In addition to the effects obtained in (1), the original can be reliably transported using the rollers.

In the image reading apparatus according to the ninth aspect, in the eighth aspect, the transporting means is configured to include a plurality of pairs of rollers that sandwich and rotate and transport the document. In addition to the effect obtained in the embodiment 8, the original can be reliably transported using the roller pair.

In the image reading apparatus according to the tenth aspect, the plurality of roller pairs are arranged at least before and after the first and second reading means. In addition to the effects obtained, the document can be smoothly transported to the reading positions of the first and second reading means.

In the image reading apparatus according to the eleventh aspect, in the tenth aspect, the nipping position at which the document is nipped by the plurality of roller pairs is located substantially on the same plane as the reading position. By arranging a plurality of roller pairs, in addition to the effect obtained in the tenth aspect, the document can be conveyed while being held substantially on the same plane at the first and second reading positions.

Further, in the image reading apparatus according to the twelfth aspect, a conveying means for conveying the original in a substantially vertical direction, and a first means for reading one side of the original conveyed by the conveying means.
And second reading means for reading the other side of the document conveyed by the conveying means, wherein the first reading means
The first reading means and the second reading means are displaced in a substantially vertical direction so that the reading position of the original by the reading means is different from the reading position of the original by the second reading means. Irrespective of the thickness and thickness, it is possible to perform good image reading without skewing or jamming of the document.

According to a thirteenth aspect of the present invention, in the twelfth aspect, the document reading position by the first reading means and the document reading position by the second reading means are located on substantially the same plane. By arranging the first reading means and the second reading means as described above, it is possible to minimize skew and jam due to the document being caught.

In the image reading apparatus according to a fourteenth aspect, the first and second image reading apparatuses are the same as in the twelfth or thirteenth aspects.
Since the reading means has an optical sensor for converting an image on the document into an image signal, the effect obtained by the twelfth or thirteenth aspect can be obtained by the image reading apparatus having the optical sensor.

According to a fifteenth aspect of the present invention, in the image reading apparatus according to the fifteenth aspect, the first and second reading means further include a lens for forming an image of light reflected from the surface to be read of the document. Thus, the effect obtained by the fourteenth aspect can be obtained by the image reading device having the lens.

In the image reading apparatus according to the present invention, the first and second reading means may further include a light source for illuminating the read surface of the document. 15 can be obtained by an image reading apparatus having a light source.

In the image reading apparatus according to the seventeenth aspect, in the sixteenth aspect, the first and second reading means further include a transparent member which abuts on the original to define a surface to be read of the original. The effect obtained by claim 16 can be obtained by the image reading apparatus having the transparent member.

In the image reading apparatus according to the present invention, the first and second reading means may further include a housing for housing the optical sensor, the lens, the light source, and the transparent member. With the configuration having the body, in addition to the effect obtained by the seventeenth aspect, each component of the first and second reading means can be stored and held.

In the image reading apparatus according to the nineteenth aspect, in any one of the twelfth to eighteenth aspects, the transporting means is configured to transport the original by a roller. In addition to the effects obtained in (1), the original can be reliably transported using the rollers.

According to a twentieth aspect of the present invention, in the image reading apparatus according to the twentieth aspect, the transporting means comprises a plurality of pairs of rollers for nipping and rotating and transporting the document. In addition to the effects obtained in 19,
The original can be reliably transported using the roller pair.

In the image reading apparatus according to the present invention, the plurality of roller pairs are arranged at least before and after the first and second reading means. In addition to the advantageous effects described above, it is possible to carry the document smoothly to the reading positions of the first and second reading means.

In the image reading apparatus according to a twenty-second aspect, in the twenty-first aspect, the nipping position at which the document is nipped by the plurality of roller pairs is located substantially on the same plane as the reading position. By arranging the plurality of roller pairs, in addition to the effect obtained in claim 21, the document can be conveyed while being held on the substantially same plane at the first and second reading positions.

The image reading apparatus according to the twenty-third aspect of the present invention is the image reading apparatus according to any one of the twelfth to twenty-second aspects, further comprising: And a second positioning means for positioning the document in opposition to the second reading means. In addition to the effects obtained in claims 12 to 22, further stable image reading can be achieved. It can be carried out.

In the image reading apparatus according to a twenty-fourth aspect, in the twenty-third aspect, the original reading position defined by the first reading means and the first positioning means, the second reading means, The first and second reading means and the first and second positioning means are respectively arranged so that the document reading position defined by the second positioning means is located on substantially the same plane, wherein: In addition to the effect obtained in 23, it is possible to prevent deterioration of the read image due to the generation of powder due to the document being rubbed at the corners of the reading means.

In the image reading apparatus according to the twenty-fifth aspect, the first and the second ones may be arranged according to the twenty-third aspect.
Since the positioning means is configured to position the document by a spring, in addition to the effect obtained in claim 23 or 24, the document can be reliably positioned by using the spring.

[Brief description of the drawings]

FIG. 1 is a diagram showing a facsimile apparatus.

FIG. 2 is a main sectional view of the image reading apparatus according to the present invention.

FIG. 3 is a sectional view of a contact image sensor.

FIG. 4 is a flowchart of a reading operation.

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

FIG. 6 is a sectional view of a conventional image reading apparatus.

FIG. 7 is a sectional view of a conventional image reading apparatus.

[Explanation of symbols]

 29 first contact image sensor 30 first pressing plate 31 first spring 32 second contact image sensor 33 second pressing plate 34 second spring

Claims (25)

[Claims] A transport unit configured to transport a document; a first reading unit configured to read one side of the document transported by the transport unit; and a positioning unit that faces the first reading unit. First positioning means; second reading means for reading the other surface of the document conveyed by the conveyance means; second positioning means for positioning the document facing the second reading means; And a document reading position defined by the first reading means and the first positioning means and a document reading position defined by the second reading means and the second positioning means are substantially on the same plane. Wherein the first and second reading means and the first and second positioning means are respectively arranged so as to be located at the same position. 2. An image reading apparatus according to claim 1, wherein said first and second reading means include an optical sensor for converting an image on said document into an image signal. 3. The image reading apparatus according to claim 2, wherein the first and second reading units further include a lens that forms an image of light reflected from a surface to be read of the document. 4. An image reading apparatus according to claim 3, wherein said first and second reading means further include a light source for illuminating a surface to be read of said document. 5. The image reading apparatus according to claim 4, wherein the first and second reading units further include a transparent member that comes into contact with the document and defines a surface to be read of the document. 6. An image reading apparatus according to claim 5, wherein said first and second reading means further include a housing for housing and holding said optical sensor, said lens, said light source and said transparent member. apparatus. 7. The image reading apparatus according to claim 1, wherein the first and second positioning units position the original using a spring. 8. An image reading apparatus according to claim 1, wherein said conveying means conveys the original by a roller. 9. An image reading apparatus according to claim 8, wherein said transport means comprises a plurality of pairs of rollers which hold and rotate and transport said document. 10. An image reading apparatus according to claim 9, wherein said plurality of roller pairs are arranged at least before and after said first and second reading means. 11. The apparatus according to claim 10, wherein the plurality of roller pairs are arranged such that a clamping position at which the document is clamped by the plurality of roller pairs is located substantially on the same plane as the reading position. Image reading device. 12. A transport unit for transporting a document in a substantially vertical direction; a first reading unit for reading one surface of the document transported by the transport unit; and the other of the document transported by the transport unit And a second reading unit for reading the surface of the first reading unit, the first reading unit and the second reading unit so that the document reading position by the first reading unit and the document reading position by the second reading unit are different. An image reading apparatus, wherein a reading unit is displaced in a substantially vertical direction. 13. The first reading unit and the second reading unit according to claim 12, wherein a document reading position by the first reading unit and a document reading position by the second reading unit are located on substantially the same plane. An image reading apparatus, wherein two reading means are arranged. 14. An image reading apparatus according to claim 12, wherein said first and second reading means include an optical sensor for converting an image on said document into an image signal. 15. An image reading apparatus according to claim 14, wherein said first and second reading means further include a lens for forming an image of reflected light from a surface to be read of said document. 16. The method according to claim 15, wherein
Wherein the reading means further comprises a light source for illuminating a surface to be read of the document. 17. The image reading apparatus according to claim 16, wherein said first and second reading means further include a transparent member which abuts on said document and defines a surface to be read of said document. 18. An image reading apparatus according to claim 17, wherein said first and second reading means further include a housing holding said optical sensor, said lens, said light source and said transparent member. apparatus. 19. An image reading apparatus according to claim 12, wherein said conveying means conveys the original by a roller. 20. An image reading apparatus according to claim 19, wherein said conveying means comprises a plurality of pairs of rollers which sandwich and rotate and convey said document. 21. An image reading apparatus according to claim 20, wherein said plurality of roller pairs are arranged at least before and after said first and second reading means. 22. The apparatus according to claim 21, wherein the plurality of rollers are arranged such that a clamping position at which the document is clamped by the plurality of roller pairs is located substantially on the same plane as the reading position. Image reading device. 23. The image forming apparatus according to claim 12, further comprising: a first positioning unit that positions the document in opposition to the first reading unit; and a second positioning unit that opposes the second reading unit. An image reading apparatus comprising: a second positioning unit that positions the document. 24. The original reading position defined by the first reading means and the first positioning means and the original reading defined by the second reading means and the second positioning means according to claim 23. An image reading apparatus, wherein the first and second reading means and the first and second positioning means are respectively arranged such that the positions are substantially on the same plane. 25. An image reading apparatus according to claim 23, wherein said first and second positioning means position the document by a spring.