JP2002057845A - Image reading system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reading system for preventing incident disturbing light to an optical reading sensor. SOLUTION: The image reading system 1 comprises an original copy inlet 6b for taking in the original copy; a transfer path 10 for transferring the original copy taken in from the original copy inlet 6b, at least one optical reading device 40 disposed on the transfer path 10 and scanning an image of the transferred original copy at a reading line X; and a pair of paper-discharging rollers 50 disposed at the downstream side of the optical reaching device 40 and discharging the original copy with its image scanned. Each roller of the pair of paper- discharging rollers 50 is composed of an integrated solid roller secured approximately equaling to a reading width of the image sensor or an extended length more than the reading width in a longitudinal direction.

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 which optically scans an original image by an optical reading apparatus and outputs the scanned original image as electronic data.

[0002]

2. Description of the Related Art Generally, the above-described image reading apparatus optically scans an original image, converts the optical image into electronic data, and transmits the electronic data to a personal computer or a facsimile. It is configured to transmit to the forming device.

[0003] Such an image reading apparatus is applied in various forms, for example, an automatic manuscript in which a plurality of manuscripts are stacked on a paper feed tray, separated one by one and automatically conveyed continuously. It is applied as a transport device (so-called ADF), incorporated in an image forming apparatus such as the above-described copying machine, or applied as an ADF to an image forming apparatus. On the other hand, there are various types of optical reading devices for reading a document image, and a typical one is a reduction optical system sensor and a one-to-one contact image sensor.

As an image reading apparatus provided with the above-described optical reading apparatus, for example, a configuration disclosed in Japanese Patent Application Laid-Open No. 5-83491 (known example 1) is known. This image reading apparatus is configured such that an optical reading apparatus having a reduced optical system sensor is vertically arranged in a conveying path so that a double-sided image of a conveyed document can be read. By a pair of paper discharge rollers disposed immediately downstream thereof (each roller is fixed at a predetermined interval along each rotation axis, and such a configuration is referred to as a “split type roller”). The paper is discharged onto a paper discharge stacker.

Japanese Patent Application Laid-Open No. Hei 10-136177 (known example 2) discloses an image reading apparatus in which a one-to-one contact type image sensor is disposed in a transport path. In order to reliably perform shading correction based on the reading reference when reading the original, the original-size close contact type image sensor includes a document transport roller (each roller is provided along each rotation axis) having a reading reference. This configuration is referred to as an “integrated roller”, and is fixed to the outside of the apparatus. Paper to be discharged.

Japanese Patent Application Laid-Open No. 11-69086 (known example 3) discloses an image in which an optical reading device using a reduction optical system sensor and an optical reading device using a unity close-contact image sensor are sequentially arranged in a transport path. A reader is disclosed. In this image reading device, the former optical reading device is disposed on a U-shaped transport path, and the latter optical reading device is disposed on a substantially linear transport path downstream of the U-shaped transport path. And a double-sided image of the conveyed document can be read. Then, the document from which the double-sided image has been read is discharged onto a discharge stacker by a discharge roller pair disposed downstream of the latter optical reading device.

[0007]

The above-described optical reading apparatus irradiates a document to be conveyed with light, and reflects the reflected light on a CCD.
Detected by a photoelectric conversion element such as an image sensor,
This is converted into a digital signal and transmitted to a personal computer or an image forming apparatus. In this case, since the image information detected by the CCD image sensor is an analog signal, if light (disturbance light) from other than the light source enters, it is detected, and noise is mixed into the transmitted data. The reading accuracy is reduced. In particular, an optical reading device using a 1: 1 contact type image sensor is susceptible to edge scattering or near scattering since glass is located near the focal position, and the area of the CCD image sensor depends on the width of the conveyed document. Since it is large, the influence of disturbance light is likely to appear.

In the configuration of the above-mentioned known example 1, since each of the paper discharge roller pairs is constituted by a split type roller, disturbance light enters from a gap between the divided rollers via a document discharge port. This easily adversely affects image processing performed by the unit-size close-contact type image sensor disposed on the upstream side. Also, in the configuration of the above-mentioned known example 2, the same-size contact image sensor is exposed to the document discharge port, and thus is more easily affected by disturbance light.

For this reason, as can be seen in the above-mentioned known example 3, it is conceivable to increase the distance between the optical reading device and the document discharge port to reduce the influence of disturbance light. (In the image reading apparatus of the known example 3, the optical reading apparatus using the same-size contact image sensor is arranged on a substantially linear transport path, and the This is not enough to prevent intrusion.)

As described above, in the conventional image reading apparatus, no consideration is given to preventing disturbance light entering from the document discharge port via the discharge roller pair.

The present invention has been made based on the above-described problem, and has as its object to provide an image reading apparatus that does not allow disturbance light to enter the optical reading apparatus. It is another object of the present invention to provide an image reading apparatus in which the size of the entire apparatus can be reduced, in addition to the above objects.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a document introduction port for introducing a document, a conveyance path for conveying the document introduced from the document introduction port, and a conveyance path for conveying the document. A pair of at least one optical reading device that is provided and scans an image of a document to be conveyed on a reading line, and a discharge roller pair that is provided downstream of the optical reading device and discharges the document on which the image is scanned. In the image reading apparatus, the rollers of the pair of paper discharge rollers are fixed along the respective rotation axes by extending in a longitudinal direction substantially corresponding to or longer than the reading width of the image sensor. It is characterized by comprising.

Further, according to the present invention, in the above-described image reading apparatus, at least one of the pair of paper discharge rollers is constituted by a split type roller fixed at a predetermined interval along a rotation axis, and the split rollers are separated from each other. And a shielding structure for preventing light from entering the optical reading device through a gap between the rollers.

Further, according to the present invention, in the above-described image reading apparatus, the nip portion between the reading line and the paper discharge roller pair is shifted so that a transport path from the reading line to the paper discharge roller pair has a step. It is characterized by being formed in.

According to the above-described configuration, disturbance light that enters the apparatus from the document discharge port through the pair of paper discharge rollers can be prevented.
There is no detection of light unrelated to the reflected light from the document.

[0016]

FIG. 1 shows an embodiment of an image reading apparatus according to the present invention, in which the image reading apparatus 1 is mounted on a copying machine 100 as an image forming apparatus.
FIG. 2 is an enlarged view of the image reading device. In this embodiment, the image reading apparatus has a function as a so-called ADF in which a document is continuously fed out and fed to the image reading unit.

The image reading apparatus 1 has a lower unit 2 and an upper unit 3 attached to the lower unit 2 by a hinge or the like so as to be freely opened and closed.

The upper unit 3 is provided with a paper feed tray 5 for stacking and storing originals, a main body 6 for conveying the originals on the paper feed tray 5 and performing image reading processing, and a paper feed tray. And a paper discharge tray 7 for discharging processed documents. The width of the documents stacked on the paper feed tray 5 is regulated by the paper feed guide 5a.

As will be described in detail below, the main body 6 has a housing 6a containing a conveyance path for conveying the original, a pair of rollers for conveying the original, an optical reading device for reading the image of the original, and the like. A document inlet 6b corresponding to the paper feed tray 5 and a document outlet 6c corresponding to the paper discharge tray 7 are formed in the housing 6a. Is transported along a substantially U-shaped transport path 10 provided in the housing, and after a reading process is performed, the paper is discharged onto the paper discharge tray 7 via a document discharge port 6c.

At the document inlet 6b of the housing 6a,
A pick-up roller 11 that feeds out the original while being in contact with the originals stacked on the paper feed tray 5 is provided. Downstream of the pickup roller 11, the fed-out original is reliably separated by one sheet. A paper separation mechanism 12 having a separation pad 12a and a separation roller 12b abutting on the separation pad 12a is provided. A registration roller pair 14 is provided on the transport path on the downstream side of the paper separating mechanism 12, and forms a bend at the leading end of the document separated by the paper separating mechanism to remove skew. ing.

The image reading apparatus according to the present embodiment has two optical reading apparatuses so that images on both sides of a conveyed document can be read.

The first optical reading device 20 is housed in the lower unit 2 and is located between a pair of transport rollers 16 and 17 continuously arranged along the transport path 10. An image of a document passing through the document 21 is read. The first optical reading device 20 includes a reduction optical system sensor, and includes a first carriage 22 and a second carriage 24. Each of the carriages 22 and 24 is driven by a motor (not shown), and moves in the unit in the left and right direction in the drawing while maintaining a predetermined distance relationship in cooperation with each other.

The carriage 22 is provided with a light source 25 for projecting irradiation light onto the document, and receives reflected light from the document of the irradiation light projected by the light source 25 and directs the reflected light to horizontal reflection light. Is mounted. Further, the carriage 24 has a reflecting mirror 28 for reflecting the reflected light in the horizontal direction reflected from the reflecting mirror 26 in the vertical direction,
A reflector 29 for reflecting the vertical light reflected by the reflector in a horizontal direction opposite to the light reflected from the reflector 26 is mounted.

Further, the first optical reading device 20 is fixed in the lower unit 2, and collects the condensing lens 30 on which the reflected light from the reflecting mirror 29 enters and the reflected light focused by the condensing lens 30. And a CCD image sensor 31 for receiving light. The light detected by the CCD image sensor 31 is converted into a digital signal by a CCD substrate 32, and then is subjected to an image processing substrate 33 for performing various image processing.
Interface board 101 in copier 100 via
Sent to.

In the present embodiment, the first optical reading device 20 is configured to read a book-type original. That is, a book reading platen 35 is provided on the upper surface of the lower unit 2 adjacent to the sheet through platen 21, and a document placed on the book reading platen is scanned by the carriages 22 and 24 moving. Then, the contents are read. Therefore, an elastic pressing member 7a for softly pressing and fixing the original placed on the book reading platen 35 is fixed to the lower surface of the paper discharge tray 7.

In the upper unit 3, a second optical reading device 40 is provided, and the first optical reading device 20 is provided.
Thus, an image on the opposite side of the original read by the above is read. The second optical reading device 40 is disposed on the transport path formed in a straight line on the downstream side of the transport roller pair 17, passes through the reading position X1 of the sheet-through platen 21, and is scooped up by the scooping guide 38. The image on the opposite side of the original is read. In the present embodiment, the second optical reading device 40 is configured to include a unit-size close-contact image sensor, specifically, a light source that emits irradiation light to a document image, Contact image sensor (C) that houses a protective glass that transmits reflected light from the CCD and a CCD image sensor that detects reflected light from a document that passes through the protective glass.
IS) unit. And CCD
After the light detected by the image sensor is converted into a digital signal by the circuit board 41, the above-described lower unit 3
Copier 100 via an image processing board 33 provided therein.
Is transmitted to the interface board 101 inside.

The second optical reading device 40 is constituted by a unit-size contact image sensor and has a small depth of focus. Therefore, the transport path in this portion is narrowed to about 0.5 mm, In order to make it easier for the document to pass through the narrowed path, the document is formed in a straight line without curving. In addition, a reference white plate (white platen) 43 for shading correction is provided on the conveyed path narrowed in such a manner as to face the same-size close-contact image sensor, and the conveyed document is kept within the allowable depth of focus. , The projection 4 corresponding to the read line X2.
5 are provided.

At the downstream side of the second optical reading device 40, a paper discharge roller pair 50 is provided, and the document read by the paper discharge roller pair is fed to the document discharge port 6
The paper is discharged onto the paper discharge tray 7 through the sheet c.

A plurality of sensors 61 to 63 for detecting the position of the document are provided on the transport path 10. Based on detection signals from these sensors, a control circuit (not shown) The registration roller pair 14 and the conveyance roller pairs 16 and 17 described above. A motor (not shown) for driving the discharge roller pair 50 and the like, the above-described movement operations of the carriages 22 and 24, and blinking control of a light source provided in each of the optical reading devices 20 and 40 are performed.

Next, the configuration of the copying machine 100 as the image forming apparatus shown in FIG. 1 will be briefly described. In the copying machine 100, a paper feed cassette 102 for stocking paper for image formation, a feed roller 103 for separating one sheet stored in the paper feed cassette 102, An image forming unit 104 for forming an image and a tray 105 for stocking paper on which the image is formed are provided.

The image forming unit 104 includes a photosensitive drum 110 for forming an image to be printed on a sheet, and a cleaning unit 111, a charging unit 112,
The image forming apparatus includes a developing device 113, a transfer device 114, and a fixing device 115 provided at a position slightly away from the transfer device. The actual image formation is performed by the cleaning device 1.
1, the charge on the drum peripheral surface is charged by the charger 112, and the uniformly charged charge is processed by the developing device 113 into a charge distribution according to a desired image. And then put the toner
This is performed by copying the toner formed on the drum onto a sheet by a transfer unit 114 and fixing the sheet by a fixing unit 115. The data for printing is stored in the image reading device 1.
Image processing board 33, shading correction performed simultaneously, white correction for normalizing quantized data after A / D conversion, density contrast correction for converting an image value to a desired brightness contrast, specific area only The data is received via the interface board 101 as data subjected to a trimming process or the like for acquiring data, and this data is processed on the printer board 120 and
3 is sent.

In this case, the copier 100 is provided with a facsimile function, and when performing the function, data is not sent to the printer board 120 but is transmitted from the modem section on the interface board 101 to the telephone line through code conversion. Sent.

Further, since the image reading apparatus 1 is configured to be capable of reading both sides of a document, a switchback mechanism (details are shown in the drawings) so that a double-sided image can be formed on the copying machine 100 side. No) is provided. Instead of the switchback mechanism, a mechanism having drums corresponding to both sides of the document may be used.

Next, the image reading apparatus 1 which is a feature of the present invention.
The configuration of the document discharge port portion will be specifically described.

FIG. 3 is an enlarged view of the document discharge port 6c of the image reading apparatus 1 shown in FIGS.
As described above, the present invention is configured such that disturbance light does not enter the optical reading device from the document discharge port.

As shown in FIG. 3, in this embodiment,
The rollers 51 and 52 that make up the paper discharge roller pair 50 and abut against each other are extended and fixed along the rotation shafts 51a and 52a in the longitudinal direction substantially corresponding to or longer than the reading width of the image sensor. It is an integrated roller, and is configured to prevent disturbance light from entering the reading line X2 of the optical reading device 40 via the document discharge port 6c. For this reason, even if the optical reading device is configured with the same-size contact type image sensor that is easily affected by disturbance light, analog signals detected by the CCD image sensor are not affected by noise because there is no intrusion of disturbance light. And the above-described image processing can be performed accurately.

Further, since the influence of disturbance light can be eliminated as described above, the optical reading device can be disposed closer to the discharge roller pair 50, and the entire image reading device can be efficiently manufactured. It is possible to reduce the size. In other words, by making the optical reading device a unit-size close-contact image sensor, the size of the entire device can be reduced, and the paper discharge roller pair 50 can be disposed immediately downstream of the optical reading device. Thus, miniaturization can be achieved more rationally. In this case, since a part of the paper discharge roller pair may be viewed from the wall of the device to the outside, a design that makes the paper discharge roller compact can be used.

It should be noted that the above-mentioned close position is defined as a position from the reading line X2 in the optical reading device
When a perpendicular line is drawn down to a plane including the centers of the respective rotation axes 51a and 52a, the distance to the intersection is about 20 m.
m or less. The basis is that the reading line is about 10 mm from the wall surface in the cross section of the optical reading device having a minimum radius of 8 to 10 mm at which the roller substantially maintains the function. That is, even in such a close position, the optical reader can be provided without being affected by disturbance light, and the entire apparatus can be efficiently reduced in size.

In this embodiment, the read line X
The nip portion of the discharge roller pair 50 is configured to substantially coincide with the extension of the document transport direction in 2. According to such a configuration, the original during the reading operation can be fed into the nip portion without being deflected. Therefore, when the optical reading device is configured by the same size contact type image sensor, the original may not move along the reading line X2. Can be prevented, and the conveyed document can be effectively regulated within the depth of focus.
At the same time, the impact generated on the document at the moment when the document enters the nip portion can be minimized.

It is preferable that the transport path from the reading line X2 to the paper discharge roller pair 50 is subjected to a dimming process. By performing such a dimming process, the intrusion of disturbance light is further suppressed. It is possible to do. In this case, the light reduction processing may be performed, for example, by making at least a part of the side surface of the transport path dark, such as black absorbing light, or taking measures such as embossing. This is preferable because there is no increase in resistance.

Next, another embodiment of the present invention will be described with reference to FIG.

In this embodiment, at least one of the rollers 54 and 55 (both in this embodiment) constituting the paper discharge roller pair 50 is fixed at predetermined intervals along the respective rotating shafts 54a and 55a. Divided roller.
A shielding structure is provided so as to prevent light from entering the optical reading device 40 through the gap between the divided rollers. In this case, the shielding structure is an optical reading device 4 disposed at a position close to the paper discharge roller pair.
The unit is supported by a side surface of the unit 0, and is constituted by a hanging member 60 hanging down from the upper discharge roller 54 to the lower discharge roller 55 on the downstream side of the discharge roller pair 50.

As shown in FIG. 4B, the hanging member 60 has a shielding portion 6 hanging down at a predetermined interval so as to shield at least a space formed between the divided rollers.
0a. In this case, it is preferable that the length of each shielding portion 60 a hang down, specifically, the leading end of each shielding portion be lower than the nip portion of the paper discharge roller pair 50. That is, with such a length, the influence of disturbance light on the reading line X2 can be suppressed. When each shielding portion has such a length, the document passing through the nip portion of the sheet discharging roller pair 50 is obstructed in the sheet discharging direction, so that the document on the reading line X2 does not fluctuate. As shown in FIG. 4A, it is desirable to form a curved portion 60b that curves downward on the back surface of each shielding portion. Also in this embodiment, similarly to the configuration shown in FIG. 3, it is preferable that at least a part of the transport path from the reading line X <b> 2 to the sheet discharge roller pair 50 is subjected to light reduction processing.

Of course, such a shielding structure may be applied to a discharge roller pair of the type shown in FIG.

Next, still another embodiment of the present invention will be described with reference to FIG.

In this embodiment, the reading line X2 in the optical reading device 40 and the nip portion of the sheet discharge roller pair 50 are shifted without being aligned with each other in the transport direction, and the sheet is discharged from the reading line X2. The transport path to the roller pair 50 is configured to have a step (the step portion is indicated by reference numeral 10a).

According to such a configuration, the step portion 10a
Accordingly, it is possible to prevent disturbance light from entering the reading line X2, and it is possible to bring the optical reading device close to the discharge roller pair. Further, according to the configuration of this embodiment, the transport roller pair 50 can be configured as a split-type roller as shown in FIG. 4 (of course, it may be configured as an integrated roller). Further, as in the above-described embodiment, it is preferable that at least a part of the step portion 10a is subjected to light reduction processing. Further, a shielding member as shown in FIG. 4 may be separately provided. . Although the step portion 10a is configured to be directed downward in the configuration shown in the drawing, it may be configured to be directed upward.

The embodiments of the present invention have been described above. However, the image reading apparatus according to the present invention is not limited to the configuration shown in the drawings, but can have various configurations. For example, in the present embodiment, the lower unit 2
And the upper unit 3. However, the lower unit 2 may be configured to be incorporated in the copying machine 100 in advance, or may be configured to integrate the ADF function and the image copying function. There may be. Further, it is sufficient that at least one optical reading device is provided, and in the case of a configuration for reading both sides of a document, it is possible to appropriately modify the optical reading device on both sides as a single-size contact image sensor. is there.

As described above, according to the present invention, disturbance light is prevented from entering the photoelectric conversion element of the optical reading device from the pair of paper discharging rollers provided at the document discharge port of the image reading device. In addition, the signal subjected to photoelectric conversion is not affected by disturbance light, and the reading accuracy does not decrease. Also,
Since the entry of disturbance light is prevented, the optical reading device can be brought closer to the paper discharge roller pair, and the size of the entire device can be reduced.

[Brief description of the drawings]

FIG. 1 shows an embodiment of an image reading apparatus according to the present invention, and shows a state in which an image forming apparatus is mounted on a copying machine.

FIG. 2 is an enlarged view of an image reading device shown in FIG. 1;

FIG. 3 is an enlarged view showing a document discharge port portion of the image reading apparatus shown in FIGS. 1 and 2;

FIG. 4 is a diagram showing another embodiment of the present invention, wherein (a)
Is an enlarged view showing a document discharge port portion of the image reading device,
(B) is a front view of the shielding member provided in the discharge port part.

FIG. 5 is a view showing still another embodiment of the present invention;
FIG. 2 is an enlarged view illustrating a document discharge port of the image reading apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image reading device 6b Document introduction port 6c Document discharge port 10 Transport path 20, 40 Optical reading device 50 Paper discharge roller pair 60 Hanging member 60a Shielding part X2 Reading line

Claims (11)

[Claims] 1. A document introduction port for introducing a document, a conveyance path for conveying the document introduced from the document introduction port, and an image of the document to be conveyed disposed on the conveyance path and scanned by a reading line. An image reading apparatus comprising: at least one optical reading apparatus; and a discharge roller pair disposed downstream of the optical reading apparatus and configured to discharge a document on which an image has been scanned. Is an image reading apparatus comprising an integral roller extending and fixed in the longitudinal direction along each rotation axis. 2. The image reading apparatus according to claim 1, wherein the optical reading apparatus has a unit-size close-contact image sensor. 3. The image reading apparatus according to claim 1, wherein a nip portion of the discharge roller pair substantially coincides with an extension of the reading line in the document conveying direction. 4. The image reading apparatus according to claim 1, wherein a light-reducing process is performed on a conveyance path from the reading line to the sheet discharge roller pair. 5. An original inlet for introducing an original, a transport path for transporting the original introduced from the original inlet, and an image of the original to be transported provided on the transport path and scanned by a reading line. An image reading apparatus, comprising: at least one optical reading apparatus; and a discharge roller pair disposed downstream of the optical reading apparatus and discharging a document on which an image has been scanned, wherein at least one of the discharge roller pair Is constituted by divided rollers fixed at predetermined intervals along the rotation axis, and provided with a shielding structure for preventing light from entering the optical reading device through gaps between the divided rollers. An image reading apparatus comprising: 6. The shielding structure includes a hanging member that hangs down from one sheet discharging roller to the other sheet discharging roller on the downstream side of the sheet discharging roller pair and shields between the divided rollers. The image reading device according to claim 5, further comprising: 7. The image reading apparatus according to claim 6, wherein the hanging member has a length to prevent a discharge direction at a nip portion of the discharge roller pair. 8. The image reading apparatus according to claim 5, wherein a light-transfer process is performed on a conveyance path from the reading line to the sheet discharge roller pair. 9. A document introduction port for introducing a document, a transport path for transporting the document introduced from the document introduction port, and an image of the document to be transported provided on the transport path and scanned by a reading line. An image reading apparatus comprising: at least one optical reading apparatus; and a discharge roller pair disposed downstream of the optical reading apparatus and configured to discharge a document on which an image has been scanned. The image reading apparatus according to claim 1, wherein a nip portion of the pair is shifted, and a conveyance path from the reading line to the discharge roller pair has a step. 10. The image reading apparatus according to claim 9, wherein a light-transfer process is performed on a conveyance path from the reading line to the sheet discharge roller pair. 11. The optical reading device according to claim 1, wherein the optical reading device is disposed close to the discharge roller pair.
11. The image reading device according to any one of claims 10 to 10.