JPH0530305A - Picture reader - Google Patents

Abstract

PURPOSE:To reduce the cost of a picture reader capable of reading pictures on both sides of an original. CONSTITUTION:For example, a carrier path 3 carrying reciprocally the original 2 in a switch-back form is provided and an image sensor 6 is arranged on the halfway of the carrier path 3 so as to be turned by 180 deg.. Then after the picture of one side of the original 2 is read in the forward path, the image sensor 6 is turned over by 180 deg. in the returning path to read the picture of the opposite side of the original 2. Thus, it is possible to read the picture of both sides of the originals by one image sensor and it is not required to provide plural expensive image sensors.

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 using an image sensor, and more particularly to a technique for reading both sides of a document.

[0002]

2. Description of the Related Art Conventionally, in an image reading apparatus such as a facsimile, a digital copying machine, an image scanner or the like, one using an image sensor for reading an image is known. In an image reading apparatus using such an image sensor, when reading both front and back sides of a document by a single document feeding operation, conventionally, a reading system dedicated to the back side is separately provided in addition to a normal reading system dedicated to the front side. It was configured to be provided.

[0003]

Therefore, the image sensor is provided separately for reading the front side of the original and for reading the back side of the original, and the cost is high because a plurality of expensive image sensors are used. there were. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a low-cost image reading apparatus capable of reading both sides of a document with one image sensor.

[0004]

Therefore, according to the present invention, in an image reading apparatus having a structure in which both front and back images of a document can be read by an image sensor in a single document feeding operation, the document is fed into a conveyance path. A single image sensor for forming an image of a moving original document, and an image forming control means for performing image formation control of images on the front surface and the rear surface of the original document with respect to the single image sensor are configured.

Here, the image forming control means is rotatably supported by a conveying means for reciprocating the original in a switchback manner and a rotary shaft parallel to the original surface and perpendicular to the original moving direction in the middle of the conveying path. Move the sensor position by rotating the single image sensor placed in the same position 180 degrees around the rotation axis until the document switches back after passing the sensor placement section and passes through the sensor placement section again. And a sensor moving means for moving the sensor.

The image forming control means includes a first light source for irradiating an upper side of a document moving on the document table with an upper side of the document table having a slit formed in a direction perpendicular to the document moving direction, and the first light source. A first reflecting mirror for reflecting and forming an image of a document illuminated by a light source in a half area of a single image sensor is provided, and a lower side of a document moving on the document table is placed below the document table. A second light source for irradiating through the slit and a second reflecting mirror for reflecting and forming an image of the original document irradiated by the second light source on the remaining half area of a single image sensor are provided.

Further, the image forming control means forms a document conveying path in a substantially horizontal Y-shape in cross section, one of the branched portions is a document feeding conveying path, and the other is a document discharging conveying path for document feeding. A first light source that has a conveying unit that switches back the original at the confluence portion after passing through the conveying path and switches and conveys the original to the side of the original conveying path, and a first light source that irradiates one side of the original moving on the feeding path. A first reflecting mirror for reflecting and forming an image of an original document illuminated by a light source on a single image sensor, and irradiating a surface of the original document on the opposite side to the one surface of the original document moving through the discharge transport path. 2 light sources and the second
A second reflecting mirror for reflecting and forming an image of a document illuminated by a light source on the single image sensor is provided.

Further, the image forming control means forms the transport path of the original document in a substantially U-shaped cross section, and uses one of the parallel portions as a document feeding transport path and the other as a document discharging transport path. , A slit portion formed at a right angle to the original moving direction penetrating from one conveying path to the other conveying path in an intermediate portion of the portions parallel to each other, and makes a U-turn of the original after passing the original conveying path. A first light source that has a conveyance unit that conveys to the document discharge conveyance path side, illuminates the upper surface of the document that moves on the feeding conveyance path, and a second light source that irradiates the upper surface of the document that moves on the discharge conveyance path. And the first
One reflecting mirror for reflecting and forming an image of a document illuminated by a light source directly and an image of a document illuminated by the second light source on a single image sensor through the slit portion, and the image sensor. The image reading apparatus according to claim 1, further comprising: a sensor position control unit that controls the position of the image sensor so as to properly focus each image to be formed.

Further, the image forming control means reflects and combines a first light source for illuminating the upper surface of the document moving in the document transport path and a top image of the document illuminated by the first light source on a single image sensor. A first reflecting mirror for forming an image; a second light source for illuminating the lower surface of the original moving on the original conveying path; and a second image for reflecting and forming a lower surface image of the original illuminated by the second light source on the single image sensor. A two-reflecting mirror and a light source control means for alternately switching the first light source and the second light source to turn on the light are provided.

[0010]

In such a structure, the image on the front surface and the back surface of the document is imaged on the single image sensor by the imaging control means during the transportation until the document is fed into the transport path and discharged. With this, it is possible to read images on both sides of the document with one image sensor.

Here, the image forming control means includes conveying means for conveying a document back and forth in a switchback manner, and after the document passes through the sensor arrangement portion in the middle of the conveying path until the document is switched back and passes through the sensor arrangement portion again. Between the image sensor 18
If the sensor moving means for rotating the sensor by 0 degree to move the sensor to the opposite side is provided, one side of the document is read when the document fed into the conveyance path passes through the image sensor section, and the sensor section is read. The image on the opposite side of the document can be read by the same image sensor by rotating the image sensor sensor until it switches back after passing and returns.

Further, the image forming control means is provided with a light source and a reflecting mirror on the upper side and the lower side of a document table having slits formed in the direction perpendicular to the document moving direction, and the image forming control means is divided into half of a single image sensor. With the configuration in which the reflected image from each reflecting mirror is formed, when the document moves on the document table, the image on the document upper surface is imaged on the half area of the image sensor and the image on the document lower surface is formed. Can be imaged through the slit on the other half of the same image sensor.

Further, in the image forming control means, the document conveying path is formed in a substantially horizontal Y-shape in cross section, one of the branched portions is used as a document feeding conveying path, and the other is used as a document discharging conveying path to feed the original. After the document passes through the transport path, the document is switched back at the merging portion to be switched to the document discharge transport path side and transported, and the light source and the reflecting mirror are arranged in each transport path, the document transport path is moved. At this time, the image on one side of the document can be read by the image sensor, and when the document discharge path is subsequently moved, the image on the opposite side of the document can be read.

Further, in the image forming control means, the document transport path is formed in a substantially U-shaped cross section, and one of the parallel portions serves as a document feed transport path and the other serves as a document discharge transport path. , A slit portion formed at a right angle to the original moving direction penetrating from one conveying path to the other conveying path in an intermediate portion of the portions parallel to each other, and makes a U-turn of the original after passing the original conveying path. It has a conveying means for conveying to the side of the document discharge conveying path, and each conveying path is provided with a light source, and the image of the original illuminated by one light source is directly and the image of the original illuminated by the other light source is the slit portion. One mirror for reflecting and forming an image on a single image sensor via the sensor, and sensor position control for controlling the position of the image sensor to properly focus each image formed on the image sensor. If the step is provided, when moving the document feeding conveying path, when the image on the upper surface of the document is read by the image sensor directly or through the slit portion, and when reversing and moving the discharging conveying path. The upper surface of the original is reversed, and this upper surface is read by the same image sensor through the slit part or directly, but at this time, the image sensor position is moved to a position in focus,
Read the image.

Further, the image forming control means are provided with light sources for illuminating the upper surface and the lower surface of the document respectively above and below the document transport path, and images of both sides of the document illuminated by each light source are obtained by a single image sensor. If a reflecting mirror for reflecting and forming images is provided on each of them and the light sources are alternately switched and turned on by the light source control means, the light sources are controlled to be alternately turned on during document feeding, so that images of the upper surface and the lower surface of the original are imaged. Can be read alternately by the same image sensor.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a first embodiment of the present invention.
In FIG. 1, for example, a pair of upper and lower plate-shaped document guide plates 1A and 1B face each other at appropriate intervals to form a conveyance path 3 for a document 2. On the upper and lower original guide plates 1A and 1B, a plurality of conveying rollers 4A and 4B are arranged at appropriate intervals along the original conveying direction so that a part of them protrudes into the gap between the guide plates. One end of the transport path 3 has an opening 5 that serves both as a document feeding section and a document discharging section, and the document 2 fed in from the opening 5 is
At the end of the conveying path, it is configured to be sent back in the opposite direction by the switchback method and discharged again from the opening 5. Further, the transport path 3 is divided into intermediate portions, and a single image sensor 6 is arranged in the intermediate portion.

The image sensor 6 is rotatably supported by a rotary shaft 7 which is parallel to the surface of the original and perpendicular to the moving direction of the original, and is switched back after the original has passed through the sensor placement section and again passes through the sensor placement section. In between, the controller 8 serving as a sensor moving means is configured to be rotationally controlled through the rotary shaft 7 so as to be rotated 180 degrees about the rotary shaft 7. In this case, it is desirable to use a contact type as the image sensor 6.

Next, the operation will be described. The original 2 fed from the opening 5 is conveyed leftward in the drawing while being sandwiched between the pair of original guide plates 1A and 1B by the conveying rollers 4A and 4B. At this time, the image sensor 6 is located on the upper side shown by the solid line in the figure, and when the document 2 passes through the image sensor 6, the image on the upper surface of the document 2 is read by the image sensor 6.

When the document 2 passes through the position of the image sensor 6, the controller 8 drives the rotary shaft 7 to rotate the image sensor 6 by 180 degrees, and the image sensor 6 is positioned below the broken line in the figure. On the other hand, the document 2 that has passed the position of the image sensor 6 is switched back when it reaches the end of the conveyance path 3 and is sent back to the right in the drawing. Then, when passing through the position of the image sensor 6, the image sensor 6 located on the lower side this time reads the image of the lower surface of the original 2 opposite to the forward path, and then the original 2 is discharged from the opening 5. It

According to this structure, the image on both sides of the original 2 can be read by one image sensor 6. Therefore, it is not necessary to provide a plurality of expensive image sensors as in the prior art, and the cost of the image reading device can be reduced. Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 2, a document table 11 fixed inside the apparatus main body
A slit 12 whose longitudinal axis is perpendicular to the conveyance direction of the original 2 is formed in the intermediate portion of the. A first light source 13 and a second light source 14 that illuminate the slit 12 position are arranged above and below the document table 11, respectively. Similarly, the upper and lower sides of the document table 11 reflect the image of the upper surface of the document 2 irradiated by the first light source 13 and the image sensor 16 through the lens 15 through the image sensor 16.
The image on the lower surface of the original 2 irradiated by the first mirror 17 as the first reflecting mirror and the second light source 14 for forming an image in the lower half area 16A is reflected through the slit 12 and the lens 15. Second image forming on the upper half area 16B of the image sensor 16
A second mirror 18 as a reflecting mirror is arranged respectively. The image sensor 16 of this embodiment uses a lens reduction type sensor in which the photosensitive portion is narrower than the document width and reduced by the lens 15 to form an image.

Next, the operation will be described. The original 2 placed on the original table 11 is moved on the original table 11 by a conveyor belt or the like (not shown). When the document 2 passes the position of the slit 12 of the document table 11, the upper surface of the document 2 is illuminated by the first light source 13, and the image on the lower surface of the document 2 is slit by the second light source 14.
Is irradiated through. Then, the respective images of the upper and lower surfaces of the document 2 which are respectively irradiated are simultaneously imaged and read by the corresponding first mirror 17 and second mirror 18 on the lower half area 16A and the upper half area 16B of the image sensor 16. Be done.

Therefore, also in the case of the second embodiment, it is possible to read the images on both sides of the original 2 by the single image sensor 16 by one operation of feeding the original. Next, a third embodiment of the present invention will be described with reference to FIG. In FIG. 3, in the present embodiment, a document transport path 3 formed by, for example, a pair of plate-shaped upper and lower document guide plates 1A and 1B on which transport rollers 4A and 4B are arranged is formed in a substantially horizontal Y shape in cross section. is there. One of the branched portions of the transport path 3 (upper side in the drawing) is used as a document feeding transport path 3A, and the other (lower side in the figure) is used as a document discharging transport path 3B. In addition, both transport paths 3
At the merging portion of A and 3B, a distribution plate 31 for switching and conveying the document 2 which is switched back and sent back in the merging / conveying path 3C after having passed through the feeding / conveying path 3A to the discharging conveying path 3B side. It is pivotally supported.

Further, in the image reading portions of the feeding path 3A and the discharging path 3B, the feeding path 3 is provided.
A first light source 13 for irradiating the lower surface of the original 2 moving in A and a second light source 14 for irradiating the upper surface of the original 2 moving in the discharge conveyance path 3B are respectively arranged. Furthermore, both transport paths 3A,
Between 3B, total reflection mirror 32A and half mirror 32B
And the prism 32 having the
The image of the original when moving A is formed on the image sensor 16 through the lens 15 through the total reflection mirror section 32A, and the image of the original when moving the discharge conveying path 3B passes through the half mirror section 32B. The image is formed on the image sensor 16 through the lens 15. Therefore, the total reflection mirror 32A
Corresponds to the first reflecting mirror, and the half mirror portion 32B corresponds to the second reflecting mirror.

Next, the operation will be described. Transfer path 3
The original 2 fed into A is irradiated with the lower surface of the original by the first light source 13 when passing through the reading section. The image of the lower surface of the illuminated document is the total reflection mirror portion 32A of the prism 32.
The light is reflected by, passes through the half mirror portion 32B, and is imaged on the image sensor 16 through the lens 15. At this time, since the reading portion of the discharging conveyance path 3B which is illuminated by the second light source 14 and enters through the half mirror portion 32B is the white reference portion,
In total, the image on the lower surface of the original 2 is read by the image sensor 16.

Document 2 that has passed through the feeding path 3A
Is distributed to the merging / conveying path 3C because the distribution plate 31 of the merging portion is at the position shown in the figure. When the document 2 is fed into the merging / conveying path 3C, the distribution plate 31 rotates clockwise in the drawing so as to open the discharging conveying path 3B side. The original 2 is sent back in the reverse direction as it is by the switchback method at the end of the merged conveyance path 3C and is sent to the ejection conveyance path 3B side by the distribution plate 31 to move on the ejection conveyance path 3C. When passing through the reading section of the discharge conveyance path 3C, the second light source 14 irradiates the upper surface of the document 2 which is the surface opposite to the surface when the feeding conveyance path 3A is moved. The illuminated image of the upper surface of the document is reflected by the half mirror portion 32B of the prism 32 and is focused on the image sensor 16 via the lens 15. At this time, the total reflection mirror portion 32A is illuminated by the first light source 13.
Since the reading portion of the feeding conveying path 3A reflected and incident on is the white reference portion, the image on the upper surface of the original 2 is read by the image sensor 16 in total.

Therefore, also in the case of the third embodiment, it is possible to read the images on both sides of the original 2 by the single image sensor 16 in one original feeding operation. Also, a prism having a total reflection mirror section 32A and a half mirror section 32B
32 is used to read the image of the document 2 on the feeding path 3A and the discharging path 3B. Therefore, when the image forming positions of both images of the image sensor 16 are adjusted, only one of them is read. The adjustment work is extremely easy as compared with the case where separate mirrors are provided and the mirrors are separately provided.

Next, a fourth embodiment of the present invention will be described with reference to FIG. In FIG. 4, in this embodiment, the transport roller 4
The document transport path 3 in which A and 4B are arranged is formed in a substantially U-shaped cross section. The upper part of the drawing which is parallel to each other in the drawing is the feeding path 3A, and the lower part of the figure is the discharging path 3B. A U-turn roller 4C is provided at the end of each of the transport paths 3A and 3B, and the original 2 is U-turned by the U-turn roller 4C at the end of the feed-in transport path 3A and the upper and lower surfaces are inverted. And is transported to the discharge transport path 3B side. In addition, a slit portion formed at a right angle to the original moving direction penetrating from the feeding conveyance path 3A toward the ejection conveyance path 3B at an intermediate portion between the feeding conveyance path 3A and the ejection conveyance path 3B.
41 is formed.

Retracting conveying path 3A and discharging conveying path 3B
A first light source 13 and a second light source 14 that irradiate the upper surface of the moving document 2 are arranged in the. In addition, above the slit portion 41, the image of the upper surface of the original 2 which is being irradiated by the first light source 13 and is moving in the feeding conveying path 3A is directly displayed.
Further, it serves as a reflecting mirror that forms an image of the upper surface of the original 2 which is being emitted from the second light source 14 and which is moving on the discharge conveying path 3B, on the single image sensor 16 through the slit portion 41 and the lens 15. A mirror 42 is arranged.

The image sensor 16 and the lens 15 are movable bodies.
It is fixed to 43 and is provided so that it can be integrally moved by a predetermined distance by the output of the controller 44. Next, the operation will be described. The document 2 fed into the feeding path 3A for feeding in the upper side of the drawing is irradiated with the upper surface of the document by the first light source 13 when passing through the reading section. The illuminated image of the upper surface of the document is reflected by the mirror 42 and is focused on the image sensor 16 via the lens 15 and read. At this time, the moving body 43 is previously moved by the controller 44 to a position where the focus of the image formed on the image sensor 16 is optimum.

Document 2 that has passed through the feeding path 3A
Is U-turned by the U-turn roller 4C at the terminal end and is sent to the discharge conveyance path 3B on the lower side in the drawing. The document 2 sent to the discharge transport path 3B is transported with its upper and lower surfaces reversed. Then, while passing through the reading section of the feeding path 3A and reaching the reading section of the discharging path 3C, the controller 15 sets the lens 15 and the image sensor 16 at a predetermined position via the moving body 43. That is, the image of the document 2 is moved to a position where the focus of the image of the document 2 is optimum when the discharge conveyance path 3B is moved. In this state, the original 2 that has reached the reading portion of the discharge conveyance path 3B is illuminated by the second light source 14 on the upper surface of the original 2 which is the surface opposite to the surface when the feeding conveyance path 3A is moved. The illuminated image of the upper surface of the original is reflected by the mirror 42 through the slit portion 41 and is reflected by the lens 42.
The image is read and imaged on the image sensor 16 via 15 at an optimum focus.

Therefore, also in the case of the fourth embodiment, it is possible to read the images on both sides of the original 2 by the single image sensor 16 by one operation of feeding the original. Next, FIG.
A fifth embodiment of the present invention will be described below. In FIG.
The conveying path 3 of the present embodiment is formed by, for example, a pair of upper and lower document guide plates 1A and 1B having a flat plate shape and facing each other with an appropriate interval, and one end is a document feeding section and the other end is a document discharging section. Has become. The upper and lower original guide plates 1A, 1
Similar to the first embodiment, a plurality of conveyance rollers 4A and 4B are arranged at B so as to partially project into the gap between the guide plates, with the proper intervals. Further, the transport path 3 is divided into an intermediate portion, and in the intermediate portion, a first light source 13 that illuminates the upper surface of the original 2 moving on the transport path 3 and a second light source that illuminates the lower surface of the original 2. 14 and are arranged.

The image of the upper surface of the document illuminated by the first light source 13 is imaged on the image sensor 16 from the lens 15 via the mirror 51 and the half mirror portion 32B of the prism 32. On the other hand, the image on the lower surface of the document illuminated by the second light source 14 is
The lens 15 through the total reflection mirror portion 32A of 52 and the prism 32
An image is formed on the image sensor 16 from. Further, the first light source 13 and the second light source 14 are configured to be alternately switched on and controlled by the controller 53 when the document 2 is passed.

Next, the operation will be described. The document 2 fed in from the document feeding portion at the left end in the figure is conveyed rightward in the figure while being sandwiched between the pair of document guide plates 1A, 1B by the conveyance rollers 4A, 4B. When the document 2 passes through the intermediate portion of the transport path 3, first, the first light source 13 is turned on to turn on the document 2.
Illuminate the upper surface of. This irradiation image is reflected by the mirror 51 and the half mirror portion 32B of the prism 32, and is focused on the image sensor 16 via the lens 15 and read. After reading the image of the upper surface of the original 2, the controller
By 53, the first light source 13 is turned off and the second light source 14 is turned on to illuminate the image on the back surface of the original 2 at the same position as the upper surface of the read original 2. The illuminated image on the back surface of the original 2 is reflected by the mirror 52 and the total reflection mirror portion 32A of the prism 32, and is focused on the image sensor 16 via the lens 15 and read. The operation of turning on and off the first light source 13 and the second light source 14 is repeated until the leading edge of the document 2 reaches the reading portion and the trailing edge of the original 2 is completely passed.

As a result, when the document 2 passes through the reading section of the transport path 3, the reading of each image on the upper surface and the lower surface of the document 2 progresses alternately, and when the document 2 finishes passing, the document 2 is read. Reading of the images on both sides of is completed. With such a configuration, it is possible to read the images on both sides of the document 2 with one image sensor 6. Therefore, it is not necessary to provide a plurality of expensive image sensors as in the prior art, and the cost of the image reading device can be reduced.

Further, the prism 32 having the total reflection mirror portion 32A and the half mirror portion 32B is used to form images on both sides of the original 2 on the image sensor.
Similar to the embodiment, there is an advantage that the work of adjusting the image forming position becomes extremely easy.

[0036]

As described above, according to the present invention, the images on both sides of the document can be read by one image sensor by one document re-feeding operation, so that it is not necessary to provide a plurality of expensive image sensors. The cost of the image reading device can be reduced.

[Brief description of drawings]

FIG. 1 is a simplified configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a simplified configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a simplified configuration diagram showing a third embodiment of the present invention.

FIG. 4 is a simplified configuration diagram showing a fourth embodiment of the present invention.

FIG. 5 is a simplified configuration diagram showing a fifth embodiment of the present invention.

[Explanation of symbols]

1A, 1B Document guide plate 2 Document 3 Transport path 4A, 4B
Conveyor rollers 6,16 Image sensor 7 Rotating shafts 8,44,53 Controller 11 Document table 12 Slit 13 First light source 14 Second light source 15 Lens 17, 18, 51, 52 Mirror 32 Prism 32A Total reflection mirror section 32 Half mirror section 43 Mobile

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location H04N 1/20 7037-5C

Claims (6)

[Claims] 1. An image reading apparatus having a structure capable of reading both front and back images of an original by an image sensor by a single original feeding operation. A single image sensor,
An image reading apparatus comprising: an image forming control means for performing image forming control of images of the front surface and the back surface of a document with respect to the single image sensor. 2. The image forming control means includes a transport means for transporting a document back and forth in a switchback manner, and a rotatably supported by a rotary shaft parallel to the document surface and orthogonal to the document moving direction in the transport path. The single image sensor placed is rotated 180 degrees about the rotation axis to move the sensor position after the document passes through the sensor placement section and before it switches back and passes through the sensor placement section again. The image reading apparatus according to claim 1, further comprising a sensor moving unit. 3. The image forming control means includes a first light source for irradiating an upper side of a document moving on the document table to an upper side of the document table having a slit formed in a direction perpendicular to a document moving direction, and the first light source. A first reflecting mirror for reflecting and forming an image of a document illuminated by a light source in a half area of a single image sensor is provided, and a lower side of a document moving on the document table is placed below the document table. A second light source for irradiating the light through the slit, and a second reflecting mirror for reflecting and forming an image of an original document irradiated by the second light source on the remaining half area of a single image sensor. Item 1. The image reading device according to item 1. 4. The image forming control means forms a document feeding path in a substantially horizontal Y-shape in cross section, one of the branched portions is a document feeding feeding path, and the other is a document discharging feeding path to feed a document. A first light source that has a conveying unit that switches back the original at the confluence portion after passing through the conveying path and switches and conveys the original to the side of the original conveying path, and a first light source that irradiates one side of the original moving on the feeding path. A first reflecting mirror for reflecting and forming an image of an original document illuminated by a light source on a single image sensor, and irradiating a surface of the original document on the opposite side to the one surface of the original document moving through the discharge transport path. 2. A structure comprising two light sources and a second reflecting mirror for reflecting and forming an image of a document illuminated by the second light source on the single image sensor.
The image reading device described. 5. The image forming control means forms a conveyance path for a document in a substantially U-shaped cross section, and uses one of the parallel portions as a document feeding conveyance path and the other as a document ejection conveyance path. , A slit portion formed at a right angle to the original moving direction penetrating from one conveying path to the other conveying path in an intermediate portion of the portions parallel to each other, and makes a U-turn of the original after passing the original conveying path. A first light source that has a conveyance unit that conveys to the document discharge conveyance path side, illuminates the upper surface of the document that moves on the feeding conveyance path, and a second light source that irradiates the upper surface of the document that moves on the discharge conveyance path. And one reflecting mirror for reflecting and forming an image of the original document irradiated by the first light source directly and an image of the original document irradiated by the second light source on a single image sensor through the slit portion. Connected to the image sensor Image reading apparatus according to claim 1 wherein the sensor position control means for controlling the position of the image sensor which is configured by providing in order to a proper focus of each image to be. 6. The image forming control means reflects a first light source for illuminating an upper surface of a document moving along a document transport path and a top image of the document illuminated by the first light source on a single image sensor. A first reflecting mirror for forming an image; a second light source for illuminating the lower surface of the original moving on the original conveying path; and a second image for reflecting and forming a lower surface image of the original illuminated by the second light source on the single image sensor. The image reading apparatus according to claim 1, further comprising a two-reflecting mirror and a light source control unit that alternately switches between the first light source and the second light source to turn on the light.