JP2004004318A - Double-sided image reader - Google Patents

Abstract

Provided is a double-sided image reading apparatus capable of separating and conveying a large number of originals and efficiently reading an image on the original even if the original is a thick paper.
A double-sided document reading apparatus includes a CCD reading unit for reading one side of a document which is separated and conveyed, a CIS for reading the other side of the document, and a document disposed between the CCD reading unit and the CIS. Of the original glass 16, springs 30a and 30b for adjusting the position of the original glass 16 with respect to the CIS 21, and a regulating member 31a. When the original P is transported, the springs 30a and 30b and the regulating member 31a adjust the position of the original glass 16 appropriately with respect to the CIS 21 so that the original P is transported smoothly. Even a thick sheet P can be stably conveyed at a high speed.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a double-sided image reading apparatus in which two reading units read images on both sides while separating and conveying a sheet-shaped document.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine that reads and prints image information of a document using an image reading device having a scanner function, the image information is read and printed while sequentially transporting a sheet-shaped document. An image reading apparatus provided with an ADF (Auto Document Feeder, automatic document feeder) for performing the reading is used.
[0003]
As an example of a conventional image reading apparatus, there is an original reading apparatus described in Japanese Patent Laid-Open Publication No. 2-97934 (publication date: April 10, 1990).
[0004]
As shown in FIG. 8, the document reading device 34 includes an upper document table 35, a lower document table 36, a paper feed roller 37, a paper discharge roller 38, a CS roller 39, a reading cover 40, a spring 41, a contact type reading sensor 42, Backup rollers 43 and 44 are provided.
[0005]
The CS roller 39 is pressed against the contact reading sensor 42 by its own weight and a spring 41 attached between the reading cover 40 and the axis of the CS roller. The axis of the CS roller 39 is fixed to a U groove of a side plate (not shown) of the document reading device 34. The CS roller 39 moves up and down along the U groove according to the thickness of the document P.
[0006]
In the configuration described above, when reading the document P, the CS roller 39 presses the document P conveyed by the paper feed roller 37 against the contact reading sensor 42, and the contact reading sensor 42 reads the document P. Thereafter, the document P is discharged by the discharge roller 38.
[0007]
Further, the CS roller 39 is also subjected to a force by a spring (not shown) in a direction in which the CS roller 39 is separated from the contact type reading sensor 42. When the reading cover 40 is opened and the document P is pulled out from between the upper document table 35 and the lower document table 36, the CS roller 39 is separated from the document P.
[0008]
On the other hand, as a conventional image reading apparatus, two reading means are provided differently from the image reading apparatus having the above-described configuration, and the two reading means read the front side and the back side of the conveyed document, respectively. There is also an image reading device.
[0009]
As an example of such an image reading apparatus, there is an automatic document feeder for reading an original described in Japanese Patent Laid-Open Publication No. 9-46472 (published on Feb. 14, 1997). .
[0010]
As shown in FIG. 9, the automatic document feeder 45 includes a loading tray 46, a paper feed roller 47, a reverse transport path 48, a first reading unit 51, a second reading unit 49, a transparent plate 50, a discharge tray 52, and a transparent tray. A document table 53 and a slide shaft 54 are provided.
[0011]
The automatic document feeder 45 supplies the originals P placed on the original placing tray 46 to the curved transport path 48 one by one by a paper feed roller 47. In the curved conveyance path 48, the supplied document P is conveyed along the path, and one surface of the document P is read by a second reading unit 49 provided in the middle.
[0012]
The original P supplied from the curved conveyance path 48 is read at the position of the transparent plate 50 by the first reading unit 51 on the other side different from the above. Then, the read document P is discharged to the discharge tray 52.
[0013]
Further, in the above configuration, the original P placed on the transparent platen 53 can be read by moving the first reading unit 51 via the slide shaft 54.
[0014]
In the above-described configuration, reading is performed by the second reading unit 49 in the middle of the curved transport path 48, and thereafter, the first reading unit 51 reads a surface different from that of the second reading unit 49. Both sides of one document can be read by conveyance.
[0015]
As another example of an image reading apparatus different from the above, there is a document reading apparatus described in Japanese Patent Laid-Open Publication No. Hei 11-27444 (publication date: January 29, 1999). .
[0016]
As shown in FIG. 10, the document reading device 56 of the copying device 55 includes a document table 57, a separation unit 58, a book scanner unit 61, a contact image sensor (CIS) 62, and a paper output tray 63. ing. The copying apparatus 55 also includes a recording unit 64 for printing information read by the document reading device 56.
[0017]
The documents P on the document tray 57 are taken out one by one and conveyed by a separation unit 58 including a separation pad 59 and a separation roller 60. For the document P to be transported, the book scanner 61 reads one side of the document P, and the CIS 62 reads the other side of the document P. Then, the read document P is discharged to the discharge tray 63.
[0018]
As a result, it is possible to read both sides of one document using the book scanner unit 61 and the CIS 62 while transporting the plurality of documents P without stopping.
[0019]
[Problems to be solved by the invention]
However, according to the configurations described in the above publications, there is a possibility that a problem that a large amount of originals cannot be handled and a thick original cannot be appropriately read may occur.
[0020]
That is, in recent years, printers provided with the above-described image reading apparatuses have been used for various purposes as compared with the related art. For example, there is a need to handle a document having a thickness that has not been conventionally handled. In addition, since it is necessary to handle a larger amount of information than in the past, it has been necessary to read a larger amount of documents at a high speed.
[0021]
However, each of the above-described configurations may have the following problems.
[0022]
That is, the configuration described in Japanese Patent Application Laid-Open No. 2-97934 is a configuration in which the CS roller 39 presses the original P conveyed from the paper feed roller 37 against the contact type reading sensor 42.
[0023]
Here, as described above, when the originals of various thicknesses are projected between the CS roller 39 and the contact type reading sensor 42 at high speed for mass printing, the CS roller 39 and the contact type reading sensor It is necessary to finely adjust the pressure between the original P and the original P. If the adjustment is not stable, the original P may be bent.
[0024]
In the automatic document feeder 45 described in Japanese Patent Application Laid-Open No. 9-46472, a second reading unit 49 is provided in the middle of a curved transport path 48 as shown in FIG. In this configuration, reading is performed by the reading unit 51. Here, in the transport to the first reading unit 51, the transport path is bent at substantially a right angle from the curved transport path 48 extending in a substantially vertical direction toward the transparent plate 50.
[0025]
For this reason, it cannot be said that there is no possibility that a shift in the reading timing occurs in the conveyance of the document P. Further, in the conveyance of the document P, there is a possibility that the document P is skewed. In particular, it cannot be said that there is no possibility that excessive conveyance will occur in a thick document.
[0026]
As shown in FIG. 10, the document reading device 56 described in Japanese Patent Application Laid-Open No. H11-27444 reads a document P on a document placing tray 57 by a book scanner 61 and a CIS 62 using a separation roller 60. This is a configuration for transporting to a position.
[0027]
For this reason, since the original P is sent to the reading position by the separation roller 60 that takes out and transports the original P, it is difficult to adjust the sending timing when a plurality of originals P are handled continuously. Therefore, when reading originals of various thicknesses at high speed for mass printing, there is a possibility that the read timing of the original P may be shifted.
[0028]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to read both sides of an image on a double-sided image capable of separating and conveying a large amount of originals and efficiently reading an image on the original even on a thick paper original. It is to provide a device.
[0029]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a duplex image reading apparatus according to the present invention includes first reading means for reading one side of a conveyed document, and second reading means for reading the other side of the document. In the double-sided image reading device, a guide member that is disposed between the first reading unit and the second reading unit and guides the conveyed document, and the position of the guide member is set to at least one of And an adjusting means for adjusting the first reading means or the second reading means.
[0030]
According to the above configuration, the guide member between the first reading unit and the second reading unit is arranged at a position adjusted by the adjusting unit, for example, with respect to the first reading unit.
[0031]
Here, the adjustment of the position of the guide member with respect to the reading means corresponds to, for example, setting the distance between the reading means and the guide member to a predetermined value by bringing the guide member into contact with the reading means. The adjustment of the position is not limited to the configuration in which the guide member is brought into contact with the reading unit, but may be another configuration.
[0032]
Therefore, the guide member guides the document at the position adjusted by the adjusting means for at least one of the reading means to perform reading, so that reading by the reading means can be performed without deteriorating the image quality of the document. it can.
[0033]
In the above configuration, if the adjusting means appropriately adjusts the position of the guide member with respect to at least one of the first reading means and the second reading means, for example, even when reading a thick paper document. Thus, the document can be smoothly transported without getting stuck between the reading means and the guide member. For this reason, for example, even when the original is transported at a high speed to handle a large number of originals, the original can be transported stably and reliably.
[0034]
Note that the first reading unit or the second reading unit in the above configuration may be any reading unit that can be used for reading an image.
[0035]
Further, the adjustment of the position of the guide member with respect to the reading means is not limited to the configuration in which the distance between the reading means and the guide member is set to a predetermined value. For example, the distance between the reading means and the guide member is within a predetermined range. For example, the distance between the document guided by the guide member and the reading unit may be set to a predetermined value, or may be set within a predetermined range. Good.
[0036]
Therefore, it is possible to provide a double-sided image reading apparatus which can separate and convey a large number of originals and can efficiently read an image on the original even for a thick original.
[0037]
In order to solve the above-mentioned problems, the double-sided image reading device according to the present invention, in the above-described configuration, wherein the first reading means is provided in a movable housing portion which is moved away from the guide member or is opposed to the guide member. The adjusting means adjusts the position of the guide member with respect to the first reading means when the movable housing portion is arranged to face the guide member.
[0038]
Here, in the above configuration, when the movable housing section is arranged to face the guide member, the first reading means of the movable housing section is also arranged to face the guide member.
[0039]
According to the above configuration, the above-described double-sided image reading device can be realized in a configuration in which the first reading unit is provided in the movable housing portion that can be arranged to face the guide member.
[0040]
Further, for example, even if the position of the first reading unit is slightly shifted with the movement of the movable housing unit, the position of the guide member is adjusted with respect to the first reading unit, and the first reading unit is adjusted. Can be reliably read.
[0041]
In the above configuration, the second reading unit may not only read the other side of the conveyed document, but also read a document placed on a document fixed mounting table.
[0042]
According to this configuration, it is possible to provide a double-sided image reading apparatus that can not only read the image on each of the front and back surfaces while transporting the document, but also read the document placed on the document fixed placing table. .
[0043]
In order to solve the above-described problems, a double-sided image reading apparatus according to the present invention is characterized in that, in the above configuration, the depth of focus of the first reading means is smaller than the depth of focus of the second reading means. .
[0044]
Here, the depth of focus means a range in the optical axis direction where a clear image can be formed before and after the focal plane when reading the document by the reading unit.
[0045]
According to the above configuration, the adjusting unit adjusts the position of the guide member with respect to the first reading unit having a small depth of focus. Therefore, reading by the first reading means can be performed more reliably. Therefore, when reading both sides of the document, the original can be read without deteriorating the image quality of each side.
[0046]
In order to solve the above-mentioned problems, the double-sided image reading device according to the present invention, in the above configuration, wherein the adjusting means adjusts the position of the guide member within the range of the depth of focus of the second reading means. Features.
[0047]
According to the above configuration, the adjusting unit adjusts the position of the guide member with respect to the first reading unit within a range of the depth of focus of the second reading unit.
[0048]
Therefore, as described above, reading by the first reading unit can be ensured, and reading by the second reading unit can be also ensured.
[0049]
Also, for example, in the double-sided image reading apparatus according to the present invention, in the above-described configuration, the adjusting unit includes a contact surface of the guide member that contacts the original when guiding the original, and at least one of the first surface The position of the guide member may be adjusted so that the reading unit or the second reading unit is separated from the reading unit by a predetermined amount.
[0050]
In the above configuration, if the contact surface of the guide member and the reading unit are separated from each other by an appropriate predetermined amount, a large number of documents can be separated and conveyed, and even a thick document can efficiently read an image on the document. A double-sided image reading device can be provided.
[0051]
That is, for example, if the contact surface of the guide member is larger than the paper thickness of the document and the reading unit is separated from the document, the thick document can be smoothly conveyed without being jammed. Further, even when a large number of originals are printed and the originals are conveyed at a high speed and read, it is possible to prevent the originals from being jammed and to surely perform stable reading.
[0052]
BEST MODE FOR CARRYING OUT THE INVENTION
One embodiment of the present invention will be described below with reference to FIGS.
[0053]
As shown in FIG. 2, a double-sided document reading apparatus (double-sided image reading apparatus) 1 according to the present embodiment includes an optical system 2 and an ADF (moving housing section) 3 disposed above the optical system. The double-sided document reading device 1 can be used as a scanner device of a copying machine or a facsimile machine, for example.
[0054]
The optical system 2 can read an image of a document (not shown) placed on the document glass 12 by a CCD (Charge Coupled Device) reading unit 11 as a second reading unit, a light source unit 13 and a mirror unit 14. At the same time, it is possible to read an image of one side of a document (not shown) being conveyed at the position of the document glass 16.
[0055]
On the other hand, the ADF 3 reads an image on the other side of the conveyed document by a contact image sensor (CIS) 21 serving as a first reading unit facing the document glass 16. Has become.
[0056]
As a result, the double-sided document reading apparatus 1 reads images on the front and back surfaces by two reading means while separating and conveying the document.
[0057]
Hereinafter, the configuration of the duplex document reading apparatus 1 will be described in more detail.
[0058]
The CCD reading unit 11 of the optical system 2 is for reading an image of a document placed on a document glass 12 and supported on a plane. The CCD reading unit 11 includes an imaging lens 11a, a CCD image sensor 11b, and the like. At the time of reading, an original image is formed on the CCD reading unit 11 by the light source unit 13 and the mirror unit 14 to perform reading.
[0059]
The light source unit 13 includes a light source 13a, a mirror 13b, a slit 13c, and a mirror 13d. When reading an original, the mirror 13b condenses the irradiation light from the light source 13a at a predetermined reading position on the original glass 12. Then, the slit 13c allows only the reflected light from the original among the incident light to pass and guides the light to the mirror 13d. The mirror 13d reflects the light incident from the slit 13c and guides the light to the mirror unit 14.
[0060]
The mirror unit 14 includes a pair of mirrors 14a and 14b for guiding light incident from the light source unit 13 to the CCD reading unit 11.
[0061]
When reading a document placed on the document glass 12, for example, the light source unit 13 moves at a predetermined speed V, and the mirror unit 14 moves in the direction of arrow 15 (sub-scanning direction) at a speed of V / 2. Then, as shown by reference numerals 13e, 13f, 14c, etc., it moves over the original glass 12, and reads the image of the placed original.
[0062]
The optical system 2 is provided with another document glass (guide member) 16 at a position separated from the document glass 12 in the sub-scanning direction.
[0063]
The original glass 16 is disposed between the CCD reading unit 11, the light source unit 13, and the mirror unit 14 as the second reading unit, and the CIS 21 as the first reading unit.
[0064]
As shown in FIG. 1, the original glass 16 receives a force in a direction approaching the CIS 21 by springs (adjustment means) 30 a and 30 b fixed to a fixed position (not shown) of the optical system 2.
[0065]
Also, as shown in FIGS. 1 and 3, the original glass 16 is regulated by a regulating member (adjustment means) 31a provided around the original glass 16 so as not to be closer to the CIS 21 than a predetermined distance. I have. The restricting member 31 may be configured to abut a part of the CIS 21 as shown in FIG. 3 or may be configured to abut another case (not shown) of the ADF 3.
[0066]
Therefore, the position of the original glass 16 with respect to the CIS 21 is adjusted by the springs 30a to 30c and the regulating members 31a and 31b as these adjusting means.
[0067]
In the cross-sectional views as shown in FIGS. 1 and 3, for example, only members having a cross section on the near side are shown and denoted by reference numerals, and members on the far side are particularly described. Not shown.
[0068]
In the original glass 16 having the above-described configuration, one surface (hereinafter referred to as a front surface) of the original P conveyed on the original glass 16 is irradiated with light while the light source unit 13 is stationary below the original glass 16. The image is reflected by the light source unit 13 and the mirror unit 14 and read by the CCD reading unit 11. The read original P is discharged to the discharge tray 17 shown in FIG.
[0069]
On the other hand, the ADF 3 has a shape that serves as a lid for the optical system 2. That is, the ADF 3 is movable with respect to the optical system 2, and the original glass 16 and the CIS 21 are arranged to be separated from each other or to be opposed to each other in accordance with opening and closing of the lid as movement.
[0070]
The ADF 3 is provided with a CIS 21 for reading a different side (hereinafter, referred to as a back side) of the conveyed document. Further, the ADF 3 includes a document tray 22, various rollers R1 to R10, sensors S1 to S6, a curved conveyance path 23, and a registration / skew correction area 24.
[0071]
The document placing tray 22 is a tray for placing a document to be read on both sides while being transported. The document placing tray 22 of the present embodiment is an electric tray having a sensor.
[0072]
As shown in FIG. 4, when no original is placed on the original placing tray 22, the position of the original placing tray 22 is arranged at a lower position.
[0073]
On the other hand, when the document placing sensor S1 composed of the actuator S1a and the sensor main body S1b detects that a document has been set on the document placing tray 22, the document placing tray 22 is moved at a predetermined timing as shown in FIG. Start climbing.
[0074]
Then, the uppermost original of the stacked original stack pushes up the pickup roller R1 supported by the arm 25 so as to be vertically movable. When the sensor S2 detects the pushup, the raising of the original placing tray 22 is stopped once. Then, it enters a standby state.
[0075]
When a document is set on the document placing tray 22 and the document placing tray 22 is raised for standby for a predetermined time as described above, the document placing tray 22 is at a predetermined level. Descend to wait.
[0076]
In the standby state described above, for example, when a document feed start signal is input by inputting a read start button of an operation unit (not shown), the paper feed roller R1 is driven to rotate as shown in FIG. Originals are sequentially taken in from the top of the bundle.
[0077]
Here, when the originals are sequentially fed and the height of the bundle of originals is reduced and the position of the paper feed roller R1 is lowered, the original placing tray 22 detects this by the sensor S2 and rises by an amount corresponding thereto. . Thus, the uppermost surface of the document bundle and the paper feed roller R1 always maintain a predetermined positional relationship and a contact state.
[0078]
Further, the document placing tray 22 can be moved up and down within a height range between the entrance side and the exit side of the curved conveyance path 23, which is necessary for the curved conveyance path 23 for conveying the document. I have. As described above, since the contact with the original is kept constant while being displaced in the vertical direction, a large amount of the original can be placed, and even when a large amount of the original is transported, the original can be transported stably. It can be carried out.
[0079]
A document separating roller R2 and a document separating plate 26 are arranged downstream of the sheet feeding roller R1 in the document conveying direction. The document separating plate 26 is urged by a spring 27 toward the document separating roller R2. Thus, even if a plurality of originals are simultaneously taken in by the paper feed roller R1, for example, only the uppermost original that is in close contact with the original separating roller R2 is taken in and conveyed to the curved conveyance path 23. It has become. Whether or not the original is separated and supplied by the original separating roller R2 is detected by a sensor S3 including an actuator S3a and a sensor main body S3b. Then, the document is guided to the curved transport path 23 on the downstream side at a predetermined timing.
[0080]
In the curved transport path 23, the original is transported by transport rollers R3 to R7. The sensor S4 including the actuator S4a and the sensor main body S4b detects the discharge of the document from the curved conveyance path 23, and determines whether the document is guided without difficulty.
[0081]
The curved conveyance path 23 has a curvature that allows the thickest, that is, the tallest document among the readable documents to be stably and smoothly conveyed. Thus, for example, the manufacturer can also guarantee a stable supply of all types of originals.
[0082]
The document discharged from the curved conveyance path 23 is conveyed to the registration / skew feeding correction area 24. When the leading edge of the document is detected by the sensor S5 disposed in front of the registration rollers R8 and R9 near the exit of the registration and skew correction region 24, the registration rollers R8 and R9 are stopped and the upstream side is stopped. The document is pressed against the registration rollers R8 and R9 for a predetermined time by the transport rollers R6 and R7. This makes it possible to correct the resist and the skew.
[0083]
Note that the sensor S5 includes an actuator S5a and a sensor main body S5b. Further, since the original is fed to the original glass 16 for reading after the original is stopped by the registration rollers R8 and R9 for a predetermined time, it is possible to prevent the reading timing of the original from being shifted.
[0084]
The registration / skew correction area 24 corresponding to the section from the last pair of conveyance rollers R6 and R7 to the pair of registration rollers R8 and R9 in the curved conveyance path 23 is used for correcting the above-described registration and skew. It is a suitable arrangement. That is, for example, between the rollers R6 and R7 and the rollers R8 and R9, the state of the document is substantially linear, and the document is designed to be as free as possible from the guide surface of the transport path.
[0085]
According to this configuration, even when a stiff original such as a thick original is conveyed, the original surface does not contact the member that guides the conveyance without bending the original. The resist and the skew can be corrected without causing the skew. Therefore, it is possible to effectively correct the resist and the skew.
[0086]
As described above, the registration / skew correction area 24 corresponds to a section from the last pair of conveyance rollers R6 and R7 to the pair of registration rollers R8 and R9 in the curved conveyance path 23. To ensure that the document is fed, the distance between the rollers R6, R7 and R8, R9 should be less than the length of the smallest document in the transport direction among the documents that can be processed as a document feeder. Preferably, there is. On the other hand, when the document is sent from the rollers R6 and R7 toward the rollers R8 and R9, the portion of the document which has been sent to the registration / skew correction area 24 is the one for correcting the registration / skew. Can be performed efficiently. For this reason, it is preferable that the distance between the rollers R6 and R7 and R8 and R9 is as long as possible.
[0087]
As described above, the document corrected in the registration / skew correction area 24 is sent out to the document glass 16 at a predetermined timing, and the document image is read.
[0088]
In the present embodiment, as shown in FIG. 1, the surface of the document P conveyed on the document glass 16 is irradiated by the light source unit 13, and the reflected light is reflected by the CCD reading unit 11 via the light source unit 13 and the mirror unit 14. And the reading is performed.
[0089]
Then, the back side of the original P conveyed on the original glass 16 is read by the CIS 21 next.
[0090]
The original glass 16 adjusts the position of the original glass 16 with respect to the CIS 21 when the ADF 3 is arranged to face the original glass 16. Thus, the original conveyed on the original glass 16 can be always read in a predetermined state.
[0091]
The irradiation position (reading position) by the light source unit 13 and the reading position by the CIS 21 are separated from each other in the document conveyance direction. Further, it is preferable that the CIS 21 is disposed near the terminal end within a limited range of the transport path length. Then, even if the document floats according to the thickness of the document at the reading position by the CIS 21, the change due to the float can be reduced and the reading by the CIS 21 can be performed more reliably.
[0092]
In the present embodiment, the CIS 21 is provided in the ADF 3 not shown in FIG. When the ADF 3 is arranged to face the document glass 16, the reading position of the document P by the CIS 21 is a fixed position in the document transport direction.
[0093]
Further, as shown in FIG. 1, when the ADF 3 is arranged to face the original glass 16, the distance between the original glass 16 and the CIS 21 is adjusted. The CIS 21 and the original glass 16 are arranged so as to be separated from each other by a predetermined amount by the regulating member 31. Therefore, the reading position of the document P by the CIS 21 is different for each document P in the optical axis direction of the CIS 21.
[0094]
Further, since the CIS 21 and the original glass 16 are separated by a predetermined amount by the regulating member 31, a document having a thickness smaller than the predetermined amount can be easily conveyed without causing any problem.
[0095]
In this way, by changing the distance between the CIS 21 and the original glass 16 within a possible range in accordance with the type (transparency and waist) of the original P, the front and back of the original P are independent of the type of the original P. Both sides can be read appropriately.
[0096]
Further, in the above configuration, the depth of focus in the CIS 21 is smaller than the depth of focus in the CCD reading unit 11.
[0097]
Here, the depth of focus means a range in the optical axis direction where a clear image can be formed before and after the focal plane when reading the document by the reading unit.
[0098]
In the present embodiment, for example, the depth of focus in the CIS 21 is about 1 mm, and the depth of focus in the CCD reading unit 11 is about 4 mm.
[0099]
Therefore, the reading position of the CCD reading unit 11 having a large depth of focus is arranged at a position closer to the registration rollers R8 and R9 and at a position where the document may float on the document glass 16, and A reading position of the CIS 21 having a small depth of focus is arranged at a position far from the rollers R8 and R9 and at a position where the floating of the document with respect to the document glass 16 is less likely to occur, so that reading can be reliably performed. .
[0100]
Further, since the position of the document glass 16 is adjusted with respect to the CIS 21 having a small depth of focus, reading can be performed more reliably.
[0101]
Further, in the above configuration, the original glass 16 is moved with respect to the CIS 21 within the range of the depth of focus of the CCD reading unit 11.
[0102]
Therefore, as described above, the reading by the CIS 21 is ensured, and the reading is also reliably performed at the reading position by the CCD reading unit 11.
[0103]
Then, the originals on which the images on the front and back sides of the original have been read are discharged from the original discharge point between the optical system 2 and the ADF 3 to the discharge tray 17 by the discharge rollers R10 and R11. The paper discharge tray 17 is provided at a position lower than the document discharge point. This document discharging operation is detected and confirmed by a sensor S6 including an actuator S6a and a sensor body S6b.
[0104]
The above operation is sequentially performed on the originals on the original placing tray 22 as shown in FIG. The process is repeated until there is no document set on the document tray 22. The read originals are all sequentially discharged onto the discharge tray 17. Further, since the paper discharge tray 17 is formed so as to protrude laterally from the main body of the double-sided document reader 1, it is possible to easily check the discharged documents and to easily take out the discharged documents. Can be done.
[0105]
As described above, the duplex document reading apparatus 1 according to the present embodiment includes the CIS 21 as the first reading unit and the CCD reading unit 11 as the second reading unit. The document glass 16 is provided between the CIS 21 and guide springs 30a to 30c for adjusting the position of the document glass 16 with respect to the CIS 21, and regulating members 31a and 31b.
[0106]
Therefore, as described above, when the document P is transported, the springs 30a to 30c and the regulating members 31a and 31b appropriately adjust the position of the document glass 16 with respect to the CIS 21 so that the document P can be smoothly moved. Since the document P is conveyed, the document P can be stably conveyed at a high speed even if the document P is a thick paper.
[0107]
In the above-described embodiment, the configuration in which the position of the original glass 16 is adjusted with respect to the CIS 21 has been described. However, the present invention is not limited to this. The configuration may also be such that the light source unit 13 that guides light toward the light source is adjusted. Further, for example, a configuration in which the position of the document glass 16 is adjusted only with respect to the light source unit 13 may be employed.
[0108]
Further, in the above-described embodiment, as the adjustment of the position of the original glass 16, the configuration in which the distance between the original glass 16 and the CIS 21 is set to a predetermined value has been described, but the present invention is not limited to this. For example, the distance between the document glass 16 and the CIS 21 may be set within a predetermined range by an appropriate adjusting unit. Further, for example, the distance between the document guided on the document glass 16 and the CIS 21 may be set to a predetermined value, or may be set within a predetermined range.
[0109]
For example, in the above-described configuration, the springs 30a to 30c and the regulating members 31a and 31b as the adjusting means may separate the document glass 16 as the guide member from the CIS 21 as the first reading means by at least a predetermined amount. Alternatively, the position of the original glass 16 may be adjusted.
[0110]
According to this configuration, the distance between the document glass 16 and the CIS 21 is at least a predetermined amount or more. Therefore, the predetermined amount is appropriately set, and even a thick sheet document can be reliably and stably conveyed.
[0111]
The configuration for realizing the adjusting means for adjusting the position of the document glass 16 as a guide member is not limited to the springs 30a to 30c and the regulating members 31a and 31b shown as an example, and any other configuration may be used. be able to.
[0112]
As shown in FIG. 8, the document reading apparatus disclosed in Japanese Patent Application Laid-Open No. 2-97934 is an example of a conventional configuration. The configuration is such that the reading sensor 42 is pressed. When originals of various thicknesses are inserted between the CS roller 39 and the contact type reading sensor 42 at high speed for mass printing, the original P may be bent.
[0113]
On the other hand, in the double-sided document reading apparatus 1 according to the present invention, as shown in FIG. 1, when the document P is transported, the springs 30a and 30b and the regulating member 31a adjust the position of the document glass 16 relative to the CIS 21. And the document P is smoothly transported. For this reason, even if the original P is a thick paper, the original P can be stably conveyed at a high speed without bending.
[0114]
Further, in the configuration described as the prior art, when reading both sides of a document with two reading units, the configuration does not take into account the difference in the focal depth and the compensation range of the focal depth for each reading unit. Was.
[0115]
On the other hand, in the embodiment according to the present invention, the arrangement of the reading position by the CIS 21 as the reading means, the CCD reading unit 11 and the like is performed in consideration of the difference in the depth of focus. Further, as described above, the position of the document glass 16 as a guide member is moved within a range in which the depth of focus of the reading unit is considered. For this reason, the original can be read more reliably than in a configuration in which the depth of focus is not considered.
[0116]
Further, the embodiment according to the present invention has a configuration in which the CIS 21 as a reading unit is provided in the ADF 3 which is separated or opposed to the original glass 16 of the optical system 2.
[0117]
In this configuration, if the lid-shaped ADF 3 is repeatedly opened and closed, the positional relationship between the original glass 16 and the CIS 20 provided on the ADF 3 may be slightly shifted.
[0118]
Therefore, in the present invention, as described above, since the position of the original glass 16 is adjusted by moving the original glass 16 with respect to the CIS 20, even if the position of the CIS 20 is slightly shifted due to opening and closing of the ADF 3, for example, the reading accuracy is improved. Can be surely read without reducing.
[0119]
Further, as another embodiment according to the present invention, for example, a document glass as a guide member is moved with respect to a CIS as a reading unit so that a distance between the document on the document glass and the CIS becomes a predetermined value. The configuration may be such that According to this configuration, it is possible to reliably read the original regardless of the thickness of the original.
[0120]
As described above, in the embodiment according to the present invention, the original glass 16 and the original reading surface of the CIS 21 are always in a predetermined state, so that reading can be performed stably and reliably.
[0121]
The following will describe another embodiment of the present invention with reference to FIG.
[0122]
The two-sided original reading apparatus 1a of the present embodiment is different from the two-sided original reading apparatus 1 only in the configuration of the original glass 16, the springs 30a to 30c, and the regulating members 31a and 31b. Hereinafter, this different point will be described. Further, the same members are referred to by the same reference numerals, and description thereof will be omitted.
[0123]
As shown in FIG. 7, the double-sided document reading apparatus 1a includes a document glass (guide member) 16a, a spring (adjusting means) 30d, and a regulating member (adjusting means) 31c.
[0124]
The original glass 16a is attached to a housing of the optical system 2 (not shown) at an axis at the pivot 16b. The document glass 16a is rotatable at a pivot 16b. The original glass 16a receives a force in a direction approaching the CIS 21 by a spring 30d.
[0125]
The original glass 16a is regulated by a regulating member 31c provided around the original glass 16 so as not to be closer to the CIS 21 than a predetermined distance.
[0126]
Therefore, the position of the document glass 16a is adjusted with respect to the CIS 21 by the spring 30d and the regulating member 31c as these adjusting means.
[0127]
In this configuration, as described above, when reading the document P, the position of the document glass 16a is adjusted to an appropriate position with respect to the CIS 21 by the spring 30d and the regulating member 30c, and reading by the CIS 21 is performed. Done.
[0128]
In this case, the original glass 16a is fixed at the rotation fulcrum 16b, and the original glass 16a does not move on the rotation fulcrum 16b side even when the original is transported. For this reason, for example, the optical path length in the CCD reading unit is not changed, so that the reading accuracy is not reduced.
[0129]
Further, since the original glass 16a is fixed on the rotation fulcrum 16b side where the original P is sent out and collides, even if a collision with the original glass 16a due to the feeding of the original P occurs, the original glass 16 is vibrated. The document can be stably conveyed without any delay.
[0130]
For example, in the cross-sectional view as shown in FIG. 7, among the members, only those having a cross section on the near side are shown and denoted by reference numerals, and members on the back side are not particularly shown. Not in.
[0131]
As described above, also in the double-sided image reading apparatus 1a of the present embodiment, the original glass 16a arranged between the CCD reading unit 11 and the CIS 21 to guide the original and the position of the original glass 16a are adjusted with respect to the CIS 21. By adjusting the position of the original glass 16a to an appropriate position with respect to the CIS 21 by the spring 30d and the regulating member 31c, even the thick original P can be stably conveyed at a high speed.
[0132]
The present invention is not limited to the above embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.
[0133]
The above-described specific embodiments or examples only clarify the technical contents of the present invention, and the present invention is not limited to such specific examples and should not be interpreted in a narrow sense. Various modifications are possible within the scope shown in the claims, and the modified embodiments are also included in the technical scope of the present invention.
[0134]
【The invention's effect】
As described above, the double-sided image reading apparatus according to the present invention is arranged between the first reading unit and the second reading unit, and guides the conveyed document, An adjusting means for adjusting a position with respect to at least one of the first reading means or the second reading means.
[0135]
Therefore, since the guide member guides the document at the position adjusted by the adjusting means to perform reading, it is possible to perform reading by the reading means without deteriorating the image quality of the document.
[0136]
Further, since the adjusting means appropriately adjusts the position of the guide member with respect to the reading means and smoothly transports the original without holding it between the reading means and the guide member, even if the original is a thick paper, Alternatively, even when the document is transported at a high speed to handle a large number of documents, the document can be transported stably and reliably.
[0137]
As described above, in the double-sided image reading device according to the present invention, in the above-described configuration, the first reading unit is provided in the movable housing unit that is arranged to be separated from or opposed to the guide member by moving, The adjusting means is configured to adjust the position of the guide member with respect to the first reading means when the movable housing portion is disposed to face the guide member.
[0138]
Therefore, in the configuration in which the first reading unit is provided in the movable housing portion that can be arranged to face the guide member, the above-described double-sided image reading device can be realized.
[0139]
As described above, in the double-sided image reading apparatus according to the present invention, in the above configuration, the depth of focus of the first reading unit is smaller than the depth of focus of the second reading unit.
[0140]
Therefore, since the adjusting means adjusts the position of the guide member with respect to the first reading means having a small depth of focus, reading by the first reading means can be performed more reliably, and both sides of the document can be read. In this case, there is an effect that reading can be performed without deteriorating the image quality of each surface.
[0141]
As described above, in the double-sided image reading apparatus according to the present invention, in the above-described configuration, the adjustment unit adjusts the position of the guide member within the range of the depth of focus of the second reading unit.
[0142]
Therefore, there is an effect that the reading by the first reading unit can be reliably performed as described above, and the reading by the second reading unit can also be reliably performed.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a part of an embodiment of a double-sided image reading apparatus according to the present invention.
FIG. 2 is a sectional view of the double-sided image reading device.
FIG. 3 is a schematic sectional view of the double-sided image reading apparatus in a different direction from FIG. 1;
FIG. 4 is a cross-sectional view showing a state before a document is placed on the double-sided image reading device.
FIG. 5 is a cross-sectional view showing a state when a document is placed on the double-sided image reading device.
FIG. 6 is a cross-sectional view showing a state of document conveyance in the double-sided image reading device.
FIG. 7 is a schematic sectional view showing another embodiment of the double-sided image reading apparatus according to the present invention.
FIG. 8 is a cross-sectional view illustrating an example of a conventional image reading apparatus.
FIG. 9 is a cross-sectional view illustrating another example of the conventional image reading apparatus.
FIG. 10 is a sectional view showing still another example of the conventional image reading apparatus.
[Explanation of symbols]
1 Double-sided document reader (double-sided image reader)
3 ADF (moving housing)
11 CCD reading unit (second reading means)
13 light source unit (second reading means)
14. Mirror unit (second reading means)
16, 16a Original glass (guide member)
21 CIS (first reading means)
30a, 30b, 30c, 30d Spring (adjustment means)
31a, 31b, 31c Restriction member (adjustment means)
P manuscript

Claims (4)

A double-sided image reading apparatus comprising: first reading means for reading one side of a conveyed document; and second reading means for reading another side of the document.
A guide member disposed between the first reading unit and the second reading unit and guiding the conveyed document;
A double-sided image reading apparatus, comprising: an adjusting unit that adjusts a position of the guide member with respect to at least one of the first reading unit and the second reading unit. The first reading means is provided in a movable housing portion which is arranged to be separated or opposed to the guide member by moving,
The said adjustment means adjusts the position of the said guide member with respect to the said 1st reading means, when the said moving housing | casing part is arrange | positioned facing the said guide member, The Claim 1 characterized by the above-mentioned. Double-sided image reader. 3. The double-sided image reading apparatus according to claim 2, wherein a depth of focus of the first reading unit is smaller than a depth of focus of the second reading unit. 4. The double-sided image reading device according to claim 3, wherein the adjusting unit adjusts a position of the guide member within a range of a depth of focus of the second reading unit. 5.

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