JP3287783B2 - Image reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus provided with a detachable hand scanner on a reading apparatus main body and capable of detecting the conveyance of a document to a conveyance path or the abnormal conveyance of a document when the apparatus is mounted.

[0002]

2. Description of the Related Art FIG. 12 is a partial sectional view showing a conventional image reading apparatus 1. As shown in FIG. The image reading device 1 includes a reading device main body 2, a hand scanner 3, and a guide rib 4.
It is comprised including. Guide ribs 4 are arranged on the upper portion of the reading device main body 2, and a transport path 5 on the document loading side is formed between them. A hand scanner 3 is mounted on the upper part of the reading device main body 2 and the guide rib 4, and a transport path 6 on the document discharge side is provided between the reading device main body 2 and the hand scanner 3.
Is formed.

In the main body 2 of the reading apparatus, a front sensor 8 is provided so that an actuator is exposed to the transport path 5, and a feed roller 9 is exposed to the transport path 5 downstream of the sensor 8 in the transport direction. Is provided. A document sensor 10 is provided further downstream of the paper feed roller 9 so that the actuator is exposed to the transport path 5, and a back roller 11 is further provided downstream of the sensor 10 and exposed to the transport path 6 downstream of the sensor 10 in the transport direction. Have been.

On one surface side of the hand scanner 3, a reading surface 12 and an S roller 13 as a guide roller are provided. At the time of mounting, the reading surface 12 is
And is abutted against. The S roller 13 is accommodated in a predetermined portion of the guide rib 4 so as not to be exposed on the transport path.

At the time of reading an image at the time of loading, the original 7 turns on the front sensor 8, whereby the paper feed roller 9 is driven, and the original 7 is carried into the conveyance path. The conveyed original 7 turns on the original sensor 10, whereby the conveyance is temporarily stopped. The document 7 conveyed again is the back roller 1
1 makes contact with the reading surface 12, at which time an image is read. The abnormal conveyance state of the document 7 is detected by the state of the front sensor 8 and the document sensor 10.

On the other hand, at the time of image reading at the time of separation, the S roller 13 is brought into contact with the surface of the document. As a result, the reading surface 12 is arranged so as to face the document surface. The image is read by moving the hand scanner 3 or the original.

FIG. 13 is a partial sectional view showing another image reading apparatus 21 of the prior art. Image reading device 21
Is configured by reversing the reading device main body of the image reading device 1 and the hand scanner, and includes a reading device main body 22, a hand scanner 23, and a guide rib 24. Guide ribs 24 are arranged at the lower portion of the reading device main body 22, and a transport path 25 on the document loading side is formed between them. A hand scanner 23 is mounted below the reading device main body 22 and the guide rib 24,
A transport path 26 on the document discharge side is formed between the scanner 2 and the hand scanner 23.

The front sensor 2 is mounted on the reading device main body 22 so that the actuator is exposed to the transport path 25.
8 is provided, and a back roller 29 is provided so as to be exposed to the transport path 26 downstream of the sensor 28 in the transport direction. On one surface side of the hand scanner 23, a reading surface 3
0 and an S roller 31 are provided. At the time of mounting, the reading surface 30 is in contact with the back roller 29 so as to face the same. The S roller 31 is not exposed on the transport path by the guide rib 24.

When reading an image at the time of mounting, the original 27
Turns on the front sensor 28. Original document 2
7 is brought into contact with a reading surface 30 by a back roller 29, and an image is read at this time. The abnormal conveyance state of the document 27 is detected by the front sensor 28. On the other hand, when the image is read at the time of detachment, the image is read in the same manner as described above.

Japanese Patent Application Laid-Open No. 6-237333 discloses a technique for preventing a document from being damaged or deformed due to a document jam in an abnormal document transport state. Specifically, the movement of the document is monitored by a jam detection roller with a mark around the photo sensor and a photo sensor, and the jam is detected based on the output of the photo sensor. Has stopped.

[0011]

In each of the image reading apparatuses 1 and 21 shown in FIGS. 12 and 13, the S rollers 13 and 29 are used only at the time of detachment and are not used at the time of mounting. Is bad. S roller 13,2
The guide ribs 4 and 24 are necessary so that the document 9 does not hinder the conveyance of the original at the time of mounting, so that the conveyance path becomes relatively complicated. Therefore, the transport load of the originals 7 and 27 is increased, and the quality of the read image data is reduced. Furthermore, the necessity of the guide ribs 4 and 24 hinders downsizing and cost reduction of the apparatus. Further, in order to detect a document jam, the image reading apparatus 1 uses the sensor 8 and the sensor 8.
10 is required, and the image reading device 21 has a sensor 28.
Is required, which leads to an increase in manufacturing cost.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a small-sized and low-cost image reading apparatus capable of detecting the conveyance of a document when the scanning apparatus is mounted on the reading apparatus main body. Another object of the present invention is to provide an image reading apparatus capable of detecting an abnormal conveyance state of a document.

[0013]

According to the present invention, there is provided a reading device main body, and a scanning device detachable from the reading device main body, wherein the scanning device reads an image while being detached from the reading device main body. An image reading device having a scanning device or a guide roller that rotates with the movement of the document when the predetermined reading surface of the scanning device is brought into contact with the document and faces the surface of the document; When mounted on the apparatus main body, a predetermined path of the reading apparatus main body and an exposed surface of the guide roller of the scanning apparatus form a document transport path, and in such a mounting, the guide roller is transported by the document conveyed to the transport path. An image reading device that includes a document conveyance detecting unit that detects rotation of the document and detects that the document is conveyed to the conveyance path. According to the invention, when the reading device main body and the scanning device are mounted, the guide roller is rotated by the document transported to the transport path, and the rotation of the guide roller detects that the document is transported to the transport path. . The document is further conveyed and faces a reading surface provided on the same exposed surface as the guide roller, where an image is read. On the other hand, at the time of separation, the reading surface is opposed to the surface of the document by bringing the guide roller into contact with the surface of the document, and the image is read by moving the scanning device or the document. Therefore, since the guide roller is used both at the time of mounting and at the time of detachment, the use efficiency of the member can be improved. In addition, since the guide roller is also used at the time of mounting, a guide rib as in the related art is unnecessary, and the transport path is relatively simple, the transport load of the document is reduced, and the quality of read image data is prevented from deteriorating. be able to. Further, since no guide rib is required, the apparatus can be downsized and the manufacturing cost can be reduced.

Further, according to the present invention, a projecting piece which comes into contact with the guide roller at the time of the mounting is provided on the reading device main body. It is characterized in that the document is sandwiched between pieces and rotated by being further transported. According to the present invention, the document held between the guide roller and the protruding piece is further transported, so that the guide roller rotates reliably, so that it is possible to reliably detect that the document has been transported to the transport path. it can.

Further, the present invention is characterized in that the projecting piece is a leaf spring. According to the present invention, the projecting piece can be realized by a leaf spring to securely hold the document.

Further, the present invention is characterized in that a document jam detecting means for detecting a jammed state of the document conveyed to the conveyance path at the time of mounting is provided. According to the present invention, it is possible to detect a jammed state of a document conveyed to the conveyance path.

Further, according to the present invention, the document jam detecting means includes a first signal output means for outputting a first signal representing a rotation period of the guide roller, and a second signal for rotating and driving the document conveying roller. Second signal output means for outputting, comparison means for comparing the output first and second signals, and determination as to whether the first and second signals are synchronized based on a comparison result of the comparison means. A determination unit that determines that the document is in a jam state when the document is not synchronized. According to the present invention, specifically, a first signal indicating the rotation cycle of the guide roller and a second signal for rotating and driving the document conveying roller are used. A jam condition can be detected.

Further, according to the present invention, the first signal output means includes:
A gear group for transmitting the rotational motion of the guide roller, an encoder having a grid in which the rotational motion of the guide roller is transmitted by the gear group, and an encoder having gratings provided at equal intervals; And a sensor that outputs According to the present invention, the first signal can be obtained by transmitting the rotational movement of the guide roller to the encoder by a group of gears and reading the encoder grid.

[0019]

FIG. 1 is a partial sectional view showing an image reading apparatus 41 according to an embodiment of the present invention. The image reading device 41 includes a reading device main body 42 and a hand scanner 43. In the reading device main body 42, a transport path 44 is formed on the document loading side, and a transport path 46 is formed on the document loading side. A hand scanner 43 is detachably disposed on an upper portion of the reading device main body 42.

At the time of mounting, a transport path 45 is formed between the reading device main body 42 and the hand scanner 43.
Therefore, at the time of loading, the original 47 passes through the transport path 44, the transport path 45, and the transport path 46 in this order, and the image is read. The front sensor 4 is mounted on the reading device main body 42 such that the actuator is exposed to the transport path 44.
The feed roller 4 is provided so as to be exposed to the transport path 44 downstream of the sensor 48 in the transport direction.
9 and a protruding piece 50 that abuts against the roller 49. The document 47 comes into contact with the actuator of the front sensor 48, and the sensor 48 is turned on.
The original 47 is conveyed while being sandwiched between the feed roller 49 and the protruding piece 50.

The hand scanner 43 is provided with an S roller 53 serving as a guide roller. The S roller 53 is exposed to the transport path 45 on the downstream side in the transport direction of the paper feed roller 49 and the projecting piece 50 so that the hand The scanner 43 is mounted. Also, the S roller 5
3 is provided with a protruding piece 51 that is in contact with and abuts the third piece 3. The protruding piece 51 is realized by, for example, a leaf spring,
At a predetermined pressure. The transported original 47 is
It is securely held between the S roller 53 and the protruding piece 51. As the document 47 is further conveyed, the S roller 53 rotates.

The hand scanner 43 also has a reading surface 54
The reading surface 54 is located on the downstream side in the transport direction of the S roller 53 and the projecting piece 51 at the time of mounting.
Exposure to 5. Further, the reading device main body 42 is provided with a back roller 52 which is opposed to and abuts on the reading surface 54. The original 47 is scanned by the back roller 52 on the reading surface 5.
4 and the image is read at this time.

The hand scanner 43 also has an S roller 53
A gear group 55 for transmitting the rotational movement of the S roller 53 is transmitted by the gear group 55, and a photo sensor 57 for reading the grid of the encoder gear 56.

On the other hand, at the time of detachment, S
The image is read by moving the hand scanner 43 or the document by bringing the roller 53 into contact with the document and the reading surface 54 facing the surface of the document. At this time, S roller 5
Reference numeral 3 rotates with the movement of the hand scanner 43 or the original, thereby reducing friction with the original or stabilizing the reading direction so as not to read at an angle. further,
Used to calculate the moving distance.

FIG. 2 is a perspective view showing the appearance of the image reading device 41. The reading device main body 42 and the hand scanner 43 are connected by a cable 58. Further, in a storage portion of the reading device main body 42 in which the hand scanner 43 is stored, there is provided a back sheet 59 which can be read by the hand scanner 43 and is provided with a predetermined mark such as a bar code.

The image reading device 41 can be realized by, for example, a facsimile device for transmitting a read image, but may be realized by an electronic device other than the facsimile device for reading an image.

FIG. 3A is a side view showing the encoder gear 56, and FIG. 3B is a front view. The encoder gear 56 is configured such that a disk-shaped encoder 61 and a gear 62 are fixed with their rotation centers coincident with each other, and further fixed to a shaft 60. The gear 62 is formed, for example, in black and blocks light. A grid is provided on the surface of the encoder 61 by openings 63 arranged at equal intervals. Gear 6
2 are provided so as to mesh with the gear group 55.
Therefore, the rotational movement of the S roller 53 is
Transmitted by the encoder 6 together with the gear 62
1 rotates. The photo sensor 57 optically reads the grating of the encoder 61. Such an encoder gear 56 is preferably small in order to reduce inertia.

FIG. 4 is a block diagram showing the electrical configuration of the image reading device 41. The reading device main body 42 of the image reading device 41 includes a CPU (Central Processing Unit) 65, a motor control signal generating circuit 66, a motor driving circuit 67, a motor, in addition to the front sensor 48, the sheet feeding roller 49 and the back roller 52. 68, a comparison detection circuit 69 and an output circuit 71. The hand scanner 43 of the image reading device 41 includes the S roller 53, a gear group 55, an encoder gear 56, and a photo sensor 57.
In addition, a reading circuit 70 is included.

The CPU 65 controls the overall operation of the image reading device 41 as a whole, and mounts the hand scanner 43 on the reading device main body 42 to read an image, and detaches the hand scanner 43 from the reading device main body 42. And a detachment reading mode for reading an image.

The motor control signal generation circuit 66 includes a CPU 6
According to the control of No. 5, a motor control signal for rotating and driving the paper feed roller 49 and the back roller 52 is generated. The motor control signal is a pulse signal at a predetermined interval. The motor drive circuit 67 drives the motor 68 according to the motor control signal generated by the motor control signal generation circuit 66, and rotates the paper feed roller 49 and the back roller 52.

When the S roller 53 of the hand scanner 43 is rotated by the loaded original, the rotation is transmitted to the encoder gear 56 by the gear group 55, the grid is read by the photo sensor 57, and the rotation of the S roller 53 is performed. An encoder signal indicating a cycle is output. The encoder signal is supplied to the comparison detection circuit 69 of the reading device main body 42 via the cable 58. The comparison control circuit 69 is also provided with a motor control signal from the motor control signal generation circuit 66, and compares the encoder signal with the motor control signal. The comparison result is given to the CPU 65, and it is determined whether or not the document jam has occurred, and whether or not the rotation of the paper feed roller 49 and the back roller 52 is stopped, based on whether or not the encoder signal and the motor control signal are synchronized with each other. .

A reading circuit 70 of the hand scanner 43;
Various signals are exchanged with the CPU 65 of the reading device main body 42 via the cable 58. The reading circuit 70 has a CPU
An image is read according to the control of 65, and the read image data is given to the CPU 65. The image data is output to the output circuit 7
1 is output. For example, it is transmitted by facsimile.

FIGS. 5 to 7 are flowcharts showing a document detecting operation and a document jam detecting operation of the image reading device 41 in the mounting reading mode. Step a
At 1, the document 47 is inserted into the transport path 44. In step a2, the front sensor 48 is turned on. In step a3, a motor control signal M as shown in FIG. 8A is generated, and the paper feed roller 49 is driven. As a result, the inserted document 47 is sandwiched between the feed roller 49 and the protruding piece 50, and is further conveyed.

In step a4, the original 47 is
3 and the projecting piece 51, and the original 47 is further transported by the paper feed roller 49, so that the S roller 53 rotates. In step a5, the rotational movement of the S roller 53 is transmitted to the encoder gear 56 by the gear group 55, and the grid of the encoder gear 56 is read by the photo sensor 57, and the S roller 53 as shown in FIG. Generates an encoder signal E representing the rotation cycle of

In step a6, since the motor control signal M and the encoder signal E have been generated, it is determined that the leading end of the document 47 has reached the S roller 53, and the S roller 53
The original 47 is conveyed by a predetermined distance from the scanning line 54 to a predetermined reading line on the reading surface 54.

In step a7, the generated encoder signal E and the motor control signal M are compared by the comparison detection circuit 69. In step a8, it is determined whether the signals E and M are synchronized with each other. Specifically, when the motor control signal M and the encoder signal E are set such that, for example, four pulses of the motor control signal M are synchronized with one pulse of the encoder signal E, the motor control signal M becomes four pulses. When it is output, it is determined whether or not one pulse of encoder signal E has been output. When the synchronization is performed, the process proceeds to step a9. When the synchronization is not performed, the process proceeds to step a12.
Proceed to.

At step a9, it is determined whether or not the front sensor 48 is on. If it is ON, the process proceeds to step a11, where the document 47 is further conveyed by a predetermined length, and the process returns to step a7. If it is not on, the process proceeds to step a10, where the document 47 is further transported by a predetermined length, and the process proceeds to step a19.

At step a12, it is determined whether or not the encoder signal E is 0. If it is 0, step a13
Then, the document 47 is further conveyed by a predetermined length, and the process proceeds to step a14. At step a14, it is determined whether or not the encoder signal E has been detected. When detected, the process returns to step a9, and when not detected, the process proceeds to step a15, where it is determined that the conveyance of the document 47 is a document jam in an abnormal state. Step a12 when it is determined in step a12 that the encoder signal E is not 0
At 18, it is determined that a document jam has occurred.

In step a16 where it is determined that the document has been jammed, the motor 68 is stopped, and the rotation of the rollers 49 and 52 is stopped. At step a17, it is output that the document is jammed, and the operation is terminated. For example, when a display unit is provided, it is displayed and output.

At step a19, it is determined whether or not the encoder signal E and the motor control signal M are synchronized.
When synchronized, the process proceeds to step a20, and the document 47 is further transported by a predetermined length, and then proceeds to step a21. When not synchronized, the process directly proceeds to step a21.

At step a21, it is determined whether or not the encoder signal E is 0. When it is 0, the process proceeds to step a22, where the document 47 is further transported by a predetermined length, and then proceeds to step a23.

In step a23, it is determined whether or not a mark on the back sheet 59 has been detected. If it is detected, the process proceeds to step a24, where the document 47 is conveyed by a predetermined length and the operation is terminated.

When it is determined in step a21 that the encoder signal E is not 0, and when a mark on the back sheet 59 is not detected in step a23, step a25 is performed.
Then, it is determined that a document jam has occurred, and the process returns to step a16.

That is, after the front sensor 48 is turned off, if the encoder control signal M is present but the encoder signal E is absent for a normal document transport without the encoder signal E, it is determined that the document jam has occurred. .

As described above, according to the present embodiment, when the reading device main body 42 and the reading hand scanner 43 are mounted,
The S roller 53 is rotated by the document 47 transported to the transport path, and the rotation of the S roller 53 detects that the document 47 is transported to the transport path. The document 47 is further conveyed and faces a reading surface 54 provided on the same exposed surface as the S roller 53, where an image is read. On the other hand, at the time of separation, the reading surface is opposed to the surface of the document by bringing the S roller 53 into contact with the surface of the document, and the image is read by moving the hand scanner 43 or the document.

Therefore, since the S roller 53 is used both at the time of mounting and at the time of detachment, it is possible to improve the utilization efficiency of the members. Further, since the S roller 53 is also used at the time of mounting, a guide rib as in the related art is not required, and the transport paths 44 to 46 are relatively simple.
It is possible to prevent a reduction in the quality of read image data due to a reduction in the conveyance load of the document. Furthermore, since no guide ribs are required, the size of the apparatus can be reduced, and the manufacturing cost can be reduced.

Further, since the document 47 sandwiched between the S roller 53 and the protruding piece 51 is further transported, the S roller 53 is reliably rotated, so that it is reliably detected that the document has been transported to the transport path. can do. Such a protruding piece 51 can be realized by a leaf spring that can securely hold the document 47.

Further, according to the present embodiment, it is possible to detect the jammed state of the document 47 conveyed to the conveyance path.
Specifically, an encoder signal E, which is a first signal representing the rotation cycle of the S roller 53, and a motor control signal M, which is a second signal for driving the paper feed roller 49 and the back roller 52, are used. Can be detected when the signals E and M are not synchronized with each other. The encoder signal E can be obtained by transmitting the rotational movement of the S roller 53 to the encoder gear 56 by the gear group 55 and reading the grid of the encoder gear 56.

FIG. 9 is a partial sectional view showing an image reading apparatus 81 according to another embodiment of the present invention. The image reading device 81 is configured by reversing the reading device main body of the image reading device 41 and the hand scanner, and includes a reading device main body 82 and a hand scanner 83. The reading device main body 82 has a conveyance path 8 on the document discharge side.
5 are formed. A hand scanner 83 is detachably disposed below the reading device main body 82.

At the time of mounting, a transport path 84 is formed between the reading device main body 82 and the hand scanner 83.
Therefore, at the time of mounting, the original 86 passes through the transport path 84 and the transport path 85 in this order, and the image is read.

The hand scanner 83 is provided with an S roller 89 serving as a guide roller, and the roller 89 is mounted so as to be exposed on the transport path 84. The reading device main body 82 is provided with a protruding piece 87 that faces and contacts the S roller 89. The protruding piece 87 is realized by a leaf spring, for example, like the protruding piece 51, and comes into contact with the S roller 89 at a predetermined pressure. Original document 86 that has been transported
Is conveyed while being held between the S roller 89 and the projecting piece 87.

The hand scanner 83 also has a reading surface 90.
When the reading surface 90 is mounted, the reading surface 90 is located downstream of the S roller 89 and the projecting piece 87 in the conveying direction.
Exposure to 4. Further, the reading device main body 82 is provided with a back roller 88 which is opposed to and abuts on the reading surface 90. The original 86 is scanned on the reading surface 9 by a back roller 88.
0, and the image is read at this time.

Similarly to the hand scanner 43, the hand scanner 83 has a gear group for transmitting the rotational movement of the S roller 89, an encoder gear for transmitting the rotational movement of the S roller 89 by the gear group, and an encoder gear for the encoder gear. It is configured to include a photo sensor for reading the grating.

On the other hand, at the time of separation, an image is read in the same manner as in the above embodiment.

FIG. 10 is a block diagram showing the electrical configuration of the image reading device 81. The image reading device 4
Circuits and members similar to those in 1 are denoted by the same reference numerals. The reading device main body 82 of the image reading device 81
8, a CPU 65, a motor control signal generation circuit 66, a motor drive circuit 67, a motor 68, a comparison detection circuit 69, and an output circuit 71. The hand scanner 83 of the image reading device 81 includes an S roller 89, a gear group 5
5, including the encoder gear 56, the photo sensor 57 and the reading circuit 70.

The CPU 65 controls the overall operation of the image reading device 81 as a whole, and mounts the hand scanner 83 on the reading device main body 82 to read an image, and detaches the hand scanner 83 from the reading device main body 82. And a detachment reading mode for reading an image.

The motor control signal generation circuit 66 includes a CPU 6
In accordance with the control of No. 5, a motor control signal for rotating and driving the back roller 88 is generated. The motor drive circuit 67
In accordance with the motor control signal generated by the motor control signal generation circuit 66, the motor 68 is driven to rotate the back roller 88.

When the S roller 89 of the hand scanner 83 is rotated by the loaded document, an encoder signal indicating the rotation cycle of the S roller 89 is output in the same manner as in the above embodiment. The comparison detection circuit 69 compares the encoder signal and the motor control signal, and determines whether the document jam has occurred based on whether the encoder signal and the motor control signal are synchronized with each other, and further determines whether the rotation of the back roller 88 is stopped. Is determined.

FIG. 11 is a flow chart showing the operation of transporting the original in the attachment reading mode of the image reading apparatus 81. In step b1, the original 86 is moved to the transport path 84.
Is inserted into. In step b2, the original 86 is sandwiched between the S roller 89 and the projecting piece 87, and the S roller 89 is rotated as the original is further conveyed. Step b3
Then, an encoder signal is generated. In step b4,
Since there is no motor control signal and an encoder signal has been generated, it is determined that the document 86 has been carried in, the motor 68 is rotated, and the back roller 88 is rotated. In step b5, the document 86 is further conveyed.

In step b6, the reading section 70 starts detecting the leading edge of the document. In step b7, it is determined whether the leading edge of the document has been detected. In step b8 where the leading edge of the document is detected, the reading unit 70 reads an image.

At step b9, it is determined whether or not the rear end of the document has been separated from the S roller 89. In step b10 where the trailing end of the document is separated, the document is conveyed by a predetermined length. In step b11, the reading unit 70
Starts detecting the trailing edge of the document. In step b12, the trailing edge of the document is detected, and the operation ends.

At the time of such document transport, the document detection operation and the document jam detection operation can be executed in the same manner as in the above-described embodiment. In this case, after the encoder signal disappears, the original 86 is transported by a predetermined length.
When the output signal is a signal representing a signal other than a mark on the back sheet 59, it is determined that a document jam has occurred.

As described above, also in this embodiment, since the S roller 89 is used both at the time of mounting and at the time of detachment, the efficiency of use of members can be improved. Also,
The guide rib as in the prior art is not required, and the transport path 8
4, 85 are relatively simple, and the load on the original document is reduced, so that the quality of the read image data can be prevented from deteriorating. Further, the size of the device can be reduced, and the manufacturing cost can be reduced. Further, it is possible to detect a jammed state of the document conveyed to the conveyance path.

Further, as compared with the image reading device 41,
Since a front sensor and a paper feed roller are not required, further downsizing and cost reduction can be achieved.

[0065]

As described above, according to the present invention, since the guide roller is used both at the time of mounting and at the time of detachment, the efficiency of use of members can be improved. In addition, since the guide roller is also used at the time of mounting, a guide rib as in the related art is not necessary, the transport path is relatively simple, the transport load of the document is reduced, and the quality of the read image data is prevented from deteriorating. be able to. Further, the size of the device can be reduced, and the manufacturing cost can be reduced. Further, since the document held between the guide roller and the protruding piece is further transported, the guide roller rotates reliably, so that it is possible to reliably detect that the document has been transported to the transport path. The projecting piece can be realized by a leaf spring that can securely hold the document.

Further, according to the present invention, it is possible to detect a jammed state of a document conveyed to the conveyance path. Specifically, when the first signal indicating the rotation period of the guide roller and the second signal for driving the document conveying roller to rotate are not synchronized, the jammed state of the document can be detected. The first signal can be obtained by transmitting the rotational motion of the guide roller to the encoder through a group of gears and reading a grid of the encoder.

[Brief description of the drawings]

FIG. 1 is an image reading apparatus 41 according to an embodiment of the present invention.
FIG.

FIG. 2 is a perspective view showing an external appearance of the image reading device 41.

FIG. 3A is a side view showing an encoder gear 56, and FIG. 3B is a front view.

FIG. 4 is a block diagram showing an electrical configuration of the image reading device 41.

FIG. 5 is a flowchart showing a document detection operation and a document jam detection operation in the attachment reading mode of the image reading device 41.

FIG. 6 is a flowchart showing a document detection operation and a document jam detection operation in the attachment reading mode of the image reading device 41.

FIG. 7 is a flowchart showing a document detection operation and a document jam detection operation in the attachment reading mode of the image reading device 41.

FIG. 8 is a timing chart showing a motor control signal M and an encoder signal E;

FIG. 9 is an image reading apparatus 8 according to another embodiment of the present invention.
FIG.

FIG. 10 is a block diagram showing an electrical configuration of the image reading device 81.

FIG. 11 is a flowchart showing a document conveying operation of the image reading device 81 in a mounting reading mode.

FIG. 12 is a partial cross-sectional view illustrating an image reading apparatus 1 according to the related art.

FIG. 13 is a partial sectional view showing another image reading apparatus 21 according to the related art.

[Explanation of symbols]

 41, 81 Image reading device 42, 82 Reading device main body 43, 83 Hand scanner 44, 45, 46, 84, 85 Transport path 47, 86 Document 48 Front sensor 49 Feed roller 50, 51, 87 Projecting piece 52, 88 Back surface Rollers 53, 89 S rollers 54, 90 Reading surface 55 Gear group 56 Encoder gear 57 Photo sensor 58 Cable 59 Back sheet 60 Shaft 61 Encoder 62 Gear 63 Opening 65 CPU 66 Motor control signal generation circuit 67 Motor drive circuit 68 Motor 69 Comparison Detection circuit 70 Reading circuit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 1/04-1/207

Claims (6)

(57) [Claims] A scanning device detachable from the reading device main body, wherein the scanning device is in contact with a document when reading an image in a state detached from the reading device main body. In an image reading apparatus having a predetermined reading surface of the scanning device facing the surface of a document and having a scanning device or a guide roller that rotates with the movement of the document, when the scanning device is mounted on the reading device main body, reading is performed. A document conveyance path is formed by a predetermined surface of the apparatus main body and an exposed surface of the guide roller of the scanning device. At the time of such mounting, rotation of the guide roller due to the document conveyed to the conveyance path is detected. An image reading apparatus, comprising: a document conveyance detection unit that detects that a document has been conveyed to a conveyance path. 2. A protruding piece that comes into contact with the guide roller at the time of the mounting is provided on the reading device main body, and the guide roller is configured to move a document conveyed to the conveyance path between the guide roller and the protruding piece. 2. The image reading apparatus according to claim 1, wherein the image reading apparatus is rotated by further conveying the nipped document. 3. The image reading apparatus according to claim 2, wherein said projecting piece is a leaf spring. 4. The image reading apparatus according to claim 1, further comprising a document jam detecting unit that detects a jammed state of the document conveyed to the conveyance path at the time of mounting. 5. The document jam detecting unit outputs a first signal indicating a rotation cycle of the guide roller, and a second signal that outputs a second signal for rotating and driving a document conveying roller. Two signal output means, comparison means for comparing the output first and second signals, and whether or not the first and second signals are synchronized with each other based on a comparison result of the comparison means. 5. The image reading apparatus according to claim 4, further comprising: a determination unit configured to determine that the document is in a jam state when the document is not jammed. 6. The first signal output means includes: a group of gears for transmitting the rotational movement of the guide roller; and an encoder having a lattice to which the rotational movement of the guide roller is transmitted by the gear group and provided at equal intervals. The image reading device according to claim 5, further comprising: a sensor that reads the grating of the encoder and outputs the first signal.