JP4112288B2 - Double-sided image reader - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a double-sided image reading apparatus in which two reading units read images on both front and back sides while separating and conveying a sheet-like 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 an original using an image reading apparatus having a scanner function, the image information is read and printed while sequentially conveying the sheet-like original. An image reading apparatus provided with an ADF (Auto Document Feeder) is used.
[0003]
As an example of a conventional image reading apparatus, there is a document reading apparatus described in Japanese published patent publication "Japanese Patent Laid-Open No. 2-97934 (published 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, and Backup rollers 43 and 44 are provided.
[0005]
The CS roller 39 is pressed against the contact-type reading sensor 42 by its own weight and a spring 41 attached between the reading cover 40 and the shaft of the CS roller. The shaft 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 paper thickness of the original P.
[0006]
In the above configuration, when reading the document P, the CS roller 39 presses the document P conveyed by the paper feed roller 37 against the contact-type reading sensor 42, and the contact-type reading sensor 42 reads the document P. Thereafter, the original P is discharged by the paper discharge roller 38.
[0007]
Further, the CS roller 39 receives a force in a direction away from the contact-type reading sensor 42 by a spring (not shown). When the reading cover 40 is opened and the document P is pulled out 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, unlike the image reading apparatus having the above-described configuration, two reading units are provided, and the two reading units respectively read the front side and the back side of the conveyed document. There is also an image reading device.
[0009]
As an example of such an image reading apparatus, there is an automatic document feeding apparatus for reading a document described in Japanese published patent publication "Japanese Patent Laid-Open No. 9-46472 (published date: February 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 conveyance path 48, a first reading unit 51, a second reading unit 49, a transparent plate 50, a discharge tray 52, a transparent tray. A document table 53 and a slide shaft 54 are provided.
[0011]
The automatic document feeder 45 supplies the document P placed on the document placement tray 46 to the curved conveyance path 48 one by one by the paper feed roller 47. In the curved conveyance path 48, the supplied original P is conveyed along the path, and one surface of the original P is read by the 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]
In the above configuration, the document P placed on the transparent document table 53 can be read by moving the first reading unit 51 via the slide shaft 54.
[0014]
In the above configuration, the second reading unit 49 in the middle of the curved conveyance path 48 performs reading, and then the first reading unit 51 reads a surface different from the second reading unit 49. Both sides of a single document can be read by conveyance.
[0015]
As another example of the image reading apparatus different from the above, there is an original reading apparatus described in Japanese published patent publication "Japanese Patent Laid-Open No. 11-27444 (publication date: January 29, 1999)". .
[0016]
As shown in FIG. 10, the document reading device 56 of the copying apparatus 55 includes a document placing table 57, a separation unit 58, a book scanner unit 61, a CIS (Contact Image Sensor: contact image sensor) 62, and a paper discharge 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 separation unit 58 including the separation pad 59 and the separation roller 60 takes out and conveys the originals P on the original placement tray 57 one by one. For the document P to be conveyed, the book scanner unit 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, both sides of one original can be read using the book scanner unit 61 and the CIS 62 while transporting a plurality of originals P without stopping.
[0019]
[Problems to be solved by the invention]
However, according to each configuration described in the above publication, there is a possibility that a large amount of originals cannot be handled and that a thick paper original cannot be read appropriately.
[0020]
That is, in recent years, printers and the like provided with the above-described image reading apparatuses have been used for various purposes as compared with the conventional printers. For example, it is necessary to handle a document having a thickness that has not been handled conventionally. Further, since it is necessary to handle a larger amount of information than in the past, it is necessary to read a larger amount of documents at high speed.
[0021]
However, there is a possibility that the following problems may occur with respect to each configuration described above.
[0022]
That is, the configuration described in Japanese Patent Laid-Open No. 2-97934 is a configuration in which the CS roller 39 presses the document P conveyed from the paper feed roller 37 against the contact-type reading sensor 42.
[0023]
Here, as described above, when a document having various thicknesses is made to enter between the CS roller 39 and the contact-type reading sensor 42 at a high speed for mass printing, the CS roller 39 and the contact-type reading sensor are used. It is necessary to finely adjust the pressure with respect to 42, and if this adjustment is not stable, the document P may be folded back.
[0024]
In the automatic document feeder 45 described in Japanese Patent Laid-Open No. 9-46472, a second reading unit 49 is provided in the middle of the curved conveyance path 48 as shown in FIG. The reading unit 51 performs reading. Here, in the conveyance to the first reading unit 51, the conveyance path is bent at a substantially right angle from the curved conveyance path 48 extending in the substantially vertical direction toward the transparent plate 50.
[0025]
For this reason, it cannot be said that there is no risk of a deviation in the reading timing during conveyance of the original P. Further, there is a possibility that the document P is transported obliquely. In particular, it cannot be said that there is no possibility of unreasonable conveyance in a thick original.
[0026]
Further, as shown in FIG. 10, the document reading device 56 described in the above-mentioned Japanese Patent Application Laid-Open No. 11-27444 reads the document P on the document placement tray 57 by using the book scanner unit 61 and the CIS 62 using the separation roller 60. It is the structure conveyed to a position.
[0027]
For this reason, since the document P is sent to the reading position by the separation roller 60 that takes out and conveys the document P, it is difficult to adjust the delivery timing when handling a plurality of documents P continuously. Therefore, when reading originals with various thicknesses at a high speed for mass printing, there is a possibility that the reading timing of the original P may be shifted.
[0028]
The present invention has been made in view of the above-described problems, and an object of the present invention is to perform double-sided image reading that can separate and convey a large amount of originals and can efficiently read an image on an original even if it is a thick paper original. To provide an apparatus.
[0029]
[Means for Solving the Problems]
In order to solve the above-described problem, a double-sided image reading apparatus according to the present invention includes a first reading unit that reads one side of a conveyed document and a second reading unit that reads the other side of the document. In the double-sided image reading apparatus, the guide member is arranged between the first reading unit and the second reading unit, and guides the document to be conveyed. And 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 with respect to the first reading unit, for example.
[0031]
Here, the adjustment of the position of the guide member relative to the reading means corresponds to 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, for example. The adjustment of the position is not limited to the configuration in which the guide member is brought into contact with the reading unit, and other configurations may be used.
[0032]
Therefore, the guide member guides and reads the document at the position adjusted by the adjusting means with respect to at least one of the reading means. Therefore, the reading by the reading means can be performed without degrading the image quality of the document. it can.
[0033]
Further, in the above configuration, even when the adjustment unit appropriately adjusts the position of the guide member with respect to at least one of the first reading unit or the second reading unit, for example, even when reading a thick paper document. The document can be transported smoothly without being caught between the reading means and the guide member. Therefore, for example, even when a document is transported at a high speed in order to handle a large amount of documents, the document can be transported stably and reliably.
[0034]
The first reading means or the second reading means in the above configuration may be any reading means that can be used for image reading.
[0035]
The adjustment of the position of the guide member with respect to the reading means is not limited to a 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 set within a predetermined range. Good.
[0036]
Therefore, it is possible to provide a double-sided image reading apparatus that can separate and convey a large amount of originals and can efficiently read an image on an original even if it is a thick original.
[0037]
In the double-sided image reading apparatus according to the present invention, in order to solve the above-described problem, in the above configuration, the first reading unit is arranged in a movable casing unit that is separated or opposed to the guide member by moving. The adjusting means is characterized in that the position of the guide member is adjusted with respect to the first reading means when the movable casing portion is disposed opposite to the guide member.
[0038]
Here, in the above configuration, when the movable casing portion is disposed opposite to the guide member, the first reading means of the movable casing portion is also disposed opposite to the guide member.
[0039]
According to the above configuration, the above-described double-sided image reading apparatus can be realized in the configuration in which the first reading unit is provided in the movable housing portion that can be disposed to face the guide member.
[0040]
In addition, for example, even if the position of the first reading unit is slightly shifted with the movement of the movable casing, the position of the guide member is adjusted with respect to the first reading unit, and the first reading unit Can be read reliably.
[0041]
In the above configuration, the second reading unit may not only read the other surface of the conveyed document, but may also read a document placed on a document fixing table.
[0042]
According to this configuration, it is possible to provide a double-sided image reading apparatus that can read not only the images on the front and back surfaces while conveying the document but also the document placed on the document fixing table. .
[0043]
In order to solve the above problems, a double-sided image reading apparatus according to the present invention is characterized in that, in the above configuration, the focal depth in the first reading means is shallower than the focal depth in the second reading means. .
[0044]
Here, the depth of focus means a range in the optical axis direction in which a clear image can be formed before and after the focal plane when the original is read by the reading unit.
[0045]
According to the above configuration, the adjusting means adjusts the position of the guide member with respect to the first reading means having a shallow focal depth. Therefore, reading by the first reading means can be performed more reliably. Therefore, when both sides of a document are read, it can be read without degrading the image quality of each side.
[0046]
In the double-sided image reading apparatus according to the present invention, in order to solve the above-described problem, in the above configuration, the adjusting unit adjusts the position of the guide member within a range of a focal depth in the second reading unit. It is a feature.
[0047]
According to the above configuration, the adjusting unit adjusts the position of the guide member with respect to the first reading unit within the range of the focal depth of the second reading unit.
[0048]
Therefore, as described above, reading by the first reading means can be ensured, and reading by the second reading means can also be ensured.
[0049]
Further, for example, in the double-sided image reading apparatus according to the present invention, in the configuration described above, the adjusting unit includes a contact surface of the guide member that contacts the document when guiding the document, and at least one of the first The position of the guide member may be adjusted so that the reading unit or the second reading unit is separated 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 amount of originals can be separated and conveyed, and an image on the original can be read efficiently even for thick originals. A double-sided image reading apparatus can be provided.
[0051]
In other words, for example, if the contact surface of the guide member and the reading unit are separated from each other and are thicker than the original, the original can be smoothly conveyed even if it is a thick original. Further, since a large amount of originals are printed, even if the originals are conveyed and read at high speed, the originals can be prevented from being caught and reliably read.
[0052]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS.
[0053]
As shown in FIG. 2, a double-sided document reading device (double-sided image reading device) 1 according to the present embodiment includes an optical system 2 and an ADF (moving housing unit) 3 disposed above the optical system 2. The double-sided document reading device 1 can be used as a scanner device for 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, a light source unit 13, and a mirror unit 14 as second reading means. In addition, an image of one side of the document (not shown) being conveyed can be read 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 with a CIS (Contact Image Sensor) 21 serving as a first reading unit disposed opposite to the document glass 16. It has become.
[0056]
As a result, the double-sided document reading device 1 reads the images on the front and back surfaces by two reading means while separating and conveying the document.
[0057]
Hereinafter, the configuration of the double-sided document reading device 1 will be described in more detail.
[0058]
The CCD reading unit 11 of the optical system 2 is for reading an image of an original placed on the original glass 12 and supported on a plane. The CCD reading unit 11 includes an imaging lens 11a and a CCD image sensor 11b. At the time of reading, the original image is formed on the CCD reading unit 11 by the light source unit 13 and the mirror unit 14 and reading is performed.
[0059]
The light source unit 13 includes a light source 13a, a mirror 13b, a slit 13c, and a mirror 13d. When reading a document, the mirror 13b condenses the irradiation light from the light source 13a at a predetermined reading position on the document glass 12. The slit 13c passes only the reflected light from the original in the incident light and guides it to the mirror 13d. The mirror 13 d reflects the light incident from the slit 13 c and guides it to the mirror unit 14.
[0060]
The mirror unit 14 includes a pair of mirrors 14 a and 14 b that guide 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 the arrow 15 (sub-scanning direction) at a speed of V / 2. Then, as indicated 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 spaced 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 means, and the CIS 21 as the first reading means.
[0064]
As shown in FIG. 1, the original glass 16 receives a force in a direction approaching the CIS 21 by springs (adjusting means) 30 a and 30 b fixed at a fixed position (not shown) of the optical system 2.
[0065]
Further, as shown in FIGS. 1 and 3, the original glass 16 is regulated so as not to be closer to the CIS 21 than a predetermined distance by a regulating member (adjusting means) 31 a provided around the original glass 16. Yes. The restricting member 31 may be configured to contact a part of the CIS 21 as shown in FIG. 3, or may be configured to contact another housing of the ADF 3 (not shown).
[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 adjusting means.
[0067]
For example, in the cross-sectional views as shown in FIG. 1 and FIG. 3, only members having a cross section on the near side are shown and attached with reference numerals. 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 document P that has been read is discharged to a paper 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. In other words, the ADF 3 is movable with respect to the optical system 2, and the original glass 16 and the CIS 21 are arranged away from each other or opposed to each other according to the opening / closing of the lid as the movement.
[0070]
The ADF 3 includes a CIS 21 for reading a different side (hereinafter referred to as a back side) of the document being conveyed. The ADF 3 also includes a document placing tray 22, various rollers R1 to R10, sensors S1 to S6, a curved conveyance path 23, and a registration / skew correction region 24.
[0071]
The document placing tray 22 is a tray for placing a document for reading both sides while being conveyed. The document placing tray 22 of this embodiment is an electric tray provided with a sensor.
[0072]
As shown in FIG. 4, when no document is placed on the document placement tray 22, the document placement tray 22 is placed at a low position.
[0073]
On the other hand, when the document placement sensor S1 including the actuator S1a and the sensor body S1b detects that a document is set on the document placement tray 22, the document placement tray 22 is moved at a predetermined timing as shown in FIG. Start climbing.
[0074]
Then, when the uppermost document of the stacked document bundle pushes up the pickup roller R1 supported by the arm 25 so as to be movable up and down, and the sensor S2 detects the pushing up, the raising of the document placing tray 22 is temporarily stopped. And enters a standby state.
[0075]
In addition, when a document is set on the document placement tray 22 and is left in a standby state after the document placement tray 22 is lifted and is in a standby state as described above, the document placement tray 22 is at a predetermined level. Descent to wait.
[0076]
In the standby state described above, for example, when a document feed start signal is input by an input of a reading start button of an operation unit (not shown), as shown in FIG. Sequentially fetch the originals from the top of the bundle.
[0077]
Here, when the originals are sequentially fed and the height of the original bundle is lowered 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 original bundle and the paper feed roller R1 always maintain a predetermined positional relationship and contact state.
[0078]
Further, the document placing tray 22 can be moved up and down within the range of the height between the entrance side and the exit side of the curved conveyance path 23 required for the curved conveyance path 23 for conveying the document. Yes. As described above, since it is displaced in the vertical direction and the contact state with the original is kept constant, a large amount of originals can be placed, and even when a large amount of originals are conveyed, the original can be stably conveyed. It can be carried out.
[0079]
A document separating roller R2 and a document separating plate 26 are disposed downstream of the sheet feeding roller R1 in the document conveying direction. The document separating plate 26 is urged toward the document separating roller R2 by a spring 27. Thus, for example, even if a plurality of documents are simultaneously captured by the paper feed roller R1, only the topmost document that is in close contact with the document handling roller R2 is captured and conveyed to the curved conveyance path 23. It has become. Further, 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 downstream curved conveyance path 23 at a predetermined timing.
[0080]
In the curved conveyance path 23, the document is conveyed by conveyance rollers R3 to R7. A sensor S4 including an actuator S4a and a sensor main body S4b detects the discharge of the document from the curved conveyance path 23, and determines whether the document has been guided without difficulty.
[0081]
The curved conveyance path 23 has a curvature capable of stably and smoothly conveying the thickest, that is, the thickest document among readable documents. For this reason, for example, the manufacturer can guarantee the stable supply of all types of documents.
[0082]
The document discharged from the curved conveyance path 23 is conveyed to the registration / skew correction region 24. When the leading edge of the document is detected by the sensor S5 disposed in front of the registration rollers R8 and R9 in the vicinity of the exit of the registration / skew correction area 24, the upstream side of the document is stopped with the registration rollers R8 and R9 stopped. The document is pressed against the registration rollers R8 and R9 for a predetermined time by the transport rollers R6 and R7. Thereby, it is possible to correct the registration and skew.
[0083]
The sensor S5 includes an actuator S5a and a sensor body S5b. Further, since the document is sent to the document glass 16 and read after the document is stopped for a predetermined time by the registration rollers R8 and R9, it is possible to prevent the reading timing of the document from being shifted.
[0084]
Further, the registration / skew correction region 24 corresponding to the section from the last pair of transport rollers R6 and R7 to the pair of registration rollers R8 and R9 in the curved transport path 23 is used for correction of registration and skew as described above. It is a suitable arrangement. That is, for example, the document is designed so that the state of the document is substantially straight between these rollers R6, R7 and R8, R9 and is as free as possible from the guide surface of the transport path.
[0085]
According to this configuration, even when a thick document such as a thick document is conveyed, the document surface is brought into contact with the member that guides conveyance without curving the document. It is possible to correct the resist and the skew without making them. Therefore, the resist and skew correction can be effectively performed.
[0086]
Further, as described above, the registration / skew correction region 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. In order to reliably feed the document, the distance between the rollers R6, R7 and R8, R9 is 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 a document is sent out from the rollers R6 and R7 toward the rollers R8 and R9, the portion of the document that has been sent to the registration / skew correction region 24 has more correction for registration / skew. Can be performed efficiently. For this reason, it is preferable that the distance between the above-described 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 region 24 is sent 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 original P conveyed on the original glass 16 is irradiated by the light source unit 13, and the reflected light is passed through the light source unit 13 and the mirror unit 14 to the CCD reading unit 11. Reading is performed.
[0089]
The original P conveyed on the original glass 16 is then read by the CIS 21 on the back side.
[0090]
The original glass 16 adjusts the position of the original glass 16 with respect to the CIS 21 when the ADF 3 is disposed opposite to the original glass 16. Thereby, the document conveyed on the document glass 16 can always be 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 transport direction. In addition, the CIS 21 is preferably arranged near the end within a limited range of the conveyance path length. By doing so, even if the original float according to the paper thickness of the original occurs at the reading position by the CIS 21, it is possible to reduce the change due to the floating and perform the reading by the CIS 21 more reliably.
[0092]
In the present embodiment, the CIS 21 is provided in the ADF 3 (not shown in FIG. 1). When the ADF 3 is disposed opposite to the original glass 16, the reading position of the original P by the CIS 21 is a fixed position in the original transport direction.
[0093]
Further, as shown in FIG. 1, when the ADF 3 is disposed opposite to 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 restriction member 31. For this reason, the reading position of the document P by the CIS 21 differs 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, an original having a thickness smaller than the predetermined amount can be easily conveyed without causing a problem.
[0095]
In this way, by changing the distance between the CIS 21 and the original glass 16 within a possible range according to the type (transparency and waist) of the original P, the front and back sides of the original P are independent of the type of the original P. Both sides can be read appropriately.
[0096]
In the above configuration, the depth of focus in the CIS 21 is shallower 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 in which a clear image can be formed before and after the focal plane when the original is read 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, a reading position by the CCD reading unit 11 having a deep focal depth is arranged at a position closer to the registration rollers R8 and R9 and where there is a possibility that the original floats on the original glass 16 may occur. A reading position of the CIS 21 having a shallow focal depth is arranged at a position far from the rollers R8 and R9 and at a position where there is little possibility of the document floating with respect to the document glass 16, so that the reading can be performed reliably. .
[0100]
Further, since the position of the original glass 16 is adjusted with respect to the CIS 21 having a shallow focal depth, reading can be performed more reliably.
[0101]
In the above configuration, the document glass 16 is moved with respect to the CIS 21 within the range of the focal depth of the CCD reading unit 11.
[0102]
For this reason, as described above, the reading by the CIS 21 is ensured and the reading by the CCD reading unit 11 is also reliably performed.
[0103]
Then, the document from which the images on both the front and back sides of the document are read is discharged from the document 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 original discharge point. The document discharge operation is detected and confirmed by the sensor S6 including the actuator S6a and the sensor body S6b.
[0104]
The above operations are sequentially performed on the document on the document placing tray 22 as shown in FIG. The process is repeated until the original set on the original placing tray 22 runs out. All the read originals are sequentially discharged onto the paper 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 reading device 1, it is possible to easily check the discharged document and to easily take out the discharged document. Can be done.
[0105]
As described above, the double-sided 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, and the CCD reading unit 11 and the CIS 21. The document glass 16 is disposed between the guide glass 16 for guiding the document, and the springs 30a to 30c and the regulating members 31a and 31b for adjusting the position of the document glass 16 with respect to the CIS 21 are provided.
[0106]
Therefore, as described above, when the document P is conveyed, 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 it is conveyed, even a thick paper original P can be stably conveyed at high speed.
[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, and for example, the position of the original glass 16 is further changed to the CCD reading unit 11. The light source unit 13 that guides light to the light source unit 13 may be 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]
In the above-described embodiment, the configuration in which the distance between the original glass 16 and the CIS 21 is set to a predetermined value as the adjustment of the position of the original glass 16 has been described. However, the present invention is not limited to this. For example, the configuration may be such that the distance between the original glass 16 and the CIS 21 is set within a predetermined range by an appropriate adjusting means. 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 set within a predetermined range.
[0109]
For example, in the above-described configuration, the springs 30a to 30c as the adjusting means and the regulating members 31a and 31b are arranged such that the distance between the original glass 16 as the guide member and the CIS 21 as the first reading means is at least a predetermined amount or more. Alternatively, the position of the original glass 16 may be adjusted.
[0110]
According to this configuration, since the distance between the document glass 16 and the CIS 21 is at least a predetermined amount or more, the predetermined amount can be set appropriately, and even a thick paper document can be reliably and stably conveyed.
[0111]
Further, the configuration for realizing the adjusting means for adjusting the position of the original glass 16 as the guide member is not limited to the springs 30a to 30c and the regulating members 31a and 31b shown as examples, and any other configuration is used. be able to.
[0112]
As shown in FIG. 8, the document reading apparatus disclosed in Japanese Patent Application Laid-Open No. 2-97934, which is given as an example of a conventional configuration, has a CS roller 39 in contact with a document P conveyed from a paper feed roller 37. In this configuration, the reading sensor 42 is pressed. When documents of various thicknesses are plunged between the CS roller 39 and the contact-type reading sensor 42 at a high speed for mass printing, the document P may be folded back.
[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, the regulating member 31a and the like appropriately position the document glass 16 with respect to the CIS 21. Thus, the original P is smoothly conveyed. For this reason, even a thick paper original P can be stably conveyed at high speed without causing buckling or the like.
[0114]
Further, in the configuration described as the prior art, when both sides of a document are read with two reading units, the configuration does not take into account differences in the focal depth and the focal depth compensation range for each reading unit. It was.
[0115]
On the other hand, in the embodiment according to the present invention, the arrangement of reading positions 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 original glass 16 as the guide member is moved within a range that takes into account the depth of focus of the reading means. For this reason, it is possible to read the document more reliably as compared with the configuration in which the depth of focus is not considered.
[0116]
In the embodiment according to the present invention, the CIS 21 as a reading unit is provided in the ADF 3 that is separated from 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 document glass 16 and the CIS 20 provided in the ADF 3 may be slightly shifted.
[0118]
Therefore, in the present invention, as described above, the position of the original glass 16 is moved and adjusted with respect to the CIS 20, so that even if the position of the CIS 20 is slightly shifted due to, for example, opening / closing of the ADF 3, the reading accuracy is increased. Can be read reliably without decreasing the.
[0119]
As another embodiment of the present invention, for example, the original glass as the guide member is moved so that the distance between the original on the original glass and the CIS is a predetermined value with respect to the CIS as the reading means. The structure to be made may be sufficient. According to this configuration, the document can be reliably read regardless of the thickness of the document.
[0120]
In this way, 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 stable and reliable reading can be performed.
[0121]
Another embodiment of the present invention will be described below with reference to FIG.
[0122]
The double-sided document reading device 1a of the present embodiment is different only in the configuration of the document glass 16, the springs 30a to 30c, and the regulating members 31a and 31b provided in the above-described double-sided document reading device 1. Hereinafter, this different point will be described. The same members are referred to by the same reference numerals, and description thereof is omitted.
[0123]
As shown in FIG. 7, the double-sided document reading device 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 the casing of the optical system 2 (not shown) with an axis at the rotation fulcrum 16b. The original glass 16a is rotatable at a rotation fulcrum 16b. The original glass 16a receives a force toward the CIS 21 by a spring 30d.
[0125]
The document glass 16a is regulated so as not to be closer to the CIS 21 than a predetermined distance by a regulation member 31c provided around the document glass 16.
[0126]
Therefore, the position of the original glass 16a is adjusted with respect to the CIS 21 by the spring 30d and the regulating member 31c as the adjusting means.
[0127]
In this configuration, when reading the original P, as described above, the position of the original 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 rotation fulcrum 16b side of the original glass 16a does not move even when the original is conveyed. For this reason, for example, since the optical path length in the CCD reading unit is not changed, reading accuracy is not lowered.
[0129]
Since the original glass 16a is fixed on the side of the pivot fulcrum 16b where the original P is fed and collides, the original glass 16 is vibrated even if the original P is collided with the original glass 16a. Therefore, it is possible to carry the document stably without using it.
[0130]
For example, in the cross-sectional view as shown in FIG. 7, only members having a cross section on the near side are illustrated with reference numerals, and the members on the back side are 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 disposed between the CCD reading unit 11 and the CIS 21 and guiding the original, and the position of the original glass 16a are adjusted with respect to the CIS 21. The position of the original glass 16a is adjusted to an appropriate position with respect to the CIS 21 by the spring 30d and the regulating member 31c, and even a thick original P can be stably conveyed at high speed.
[0132]
The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.
[0133]
The specific embodiments or examples described above are merely to 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 can be made within the scope of the claims, and the modified forms 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 means and the second reading means, and guides the document to be conveyed, and the guide member And an adjusting means for adjusting the position with respect to at least one of the first reading means and the second reading means.
[0135]
Therefore, the guide member guides and reads the document at the position adjusted by the adjusting unit, so that the reading by the reading unit can be read without degrading the image quality of the document.
[0136]
In addition, since the adjusting unit appropriately adjusts the position of the guide member with respect to the reading unit and smoothly conveys the original without holding the original between the reading unit and the guide member, In addition, even when a document is transported at a high speed in order to handle a large amount of documents, the document can be transported stably and reliably.
[0137]
As described above, in the double-sided image reading apparatus according to the present invention, in the above-described configuration, the first reading unit is provided in a movable casing unit that is separated 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, the above-described double-sided image reading apparatus can be realized in the configuration in which the first reading unit is provided in the movable housing portion that can be disposed to face the guide member.
[0139]
As described above, the double-sided image reading apparatus according to the present invention has a configuration in which the depth of focus in the first reading unit is shallower than the depth of focus in the second reading unit.
[0140]
Therefore, the adjusting means adjusts the position of the guide member with respect to the first reading means having a shallow depth of focus, so that the reading by the first reading means can be performed more reliably and both sides of the document are read. In this case, there is an effect that reading can be performed without degrading the image quality of each surface.
[0141]
As described above, the double-sided image reading apparatus according to the present invention has a configuration in which the adjusting unit adjusts the position of the guide member within the range of the focal depth in the second reading unit.
[0142]
Therefore, as described above, there is an effect that the reading by the first reading means can be ensured and the reading by the second reading means can be surely performed.
[Brief description of the drawings]
FIG. 1 is a cross-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 apparatus.
FIG. 3 is a schematic cross-sectional view of the double-sided image reading apparatus in a different direction from FIG.
FIG. 4 is a cross-sectional view showing a state before placing a document on the double-sided image reading apparatus.
FIG. 5 is a cross-sectional view showing a state where an original is placed on the double-sided image reading apparatus.
FIG. 6 is a cross-sectional view showing a state of document conveyance in the double-sided image reading apparatus.
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 showing an example of a conventional image reading apparatus.
FIG. 9 is a cross-sectional view showing another example of a conventional image reading apparatus.
FIG. 10 is a cross-sectional view showing still another example of a 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 Document 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)

In a double-sided image reading apparatus comprising: a first reading unit comprising a contact image sensor that reads one side of a conveyed document; and a second reading unit that reads the other side of the document.
The provided movably with respect to the first reading means and the second the reading means arranged Rutotomoni the first and second between the reading means, for guiding the lower surface of the document conveyed A guide member;
By moving the guide member in the optical axis direction of the first reading means, the position of the guide member is set to the first position so that the separation distance between the first reading means and the guide member becomes a predetermined value. Adjusting means for adjusting the reading means ,
The first reading means is provided in a moving housing part that is separated or opposed to the guide member by moving,
The double-sided image reading apparatus , wherein the adjusting means adjusts the position of the guide member when the movable casing is disposed to face the guide member . A spring that urges the adjusting means in a direction to bring the guide member closer to the movable casing in a state of being opposed to the guide member;
The double-sided image reading apparatus according to claim 1, further comprising a regulating member provided on the guide member for regulating a separation distance between the guide member and the first reading unit . 3. The double-sided image reading apparatus according to claim 1, wherein a depth of focus in the second reading unit is deeper than a depth of focus in the first reading unit.   4. The double-sided image reading apparatus according to claim 3, wherein the adjusting unit adjusts the position of the guide member within a range of a focal depth in the second reading unit.

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