JPH04365259A - Image reader - Google Patents

Abstract

PURPOSE:To set a read start position corresponding to the fitting position of a feeding means by setting the read start position by reading a read start position reference provided at the feeding means by a reading means. CONSTITUTION:A read start position reference 90 is provided at a feeding means (ADF) 80, this read start position reference 90 is read by a reading means (exposure scan means) and the read start position is set. Namely, a marker 90 is provided as a read start reference showing an original read start position (ADF position) on the lower face of an original lower guide 20 in the main scan area in the case of ADF and out of the read area of an original P, and a window W is provided at a position as a size index corresponding to the marker 90. The marker 90 is read by the exposure scan means and corresponding to the fitting position of the ADF 80 to a main body 81 of an image device, the ADF position is set in the moving direction of the ADF 80. When the original P is fed to the prescribed position at the main body 81 of the device by the ADF 80, the exposure scan means moves from the ADF position in a prescribed direction and reads the image of the original.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to image reading devices such as copying machines and scanners, and more specifically, the present invention relates to image reading devices such as copying machines and scanners. The present invention relates to an image reading device that feeds paper and reads image information of a document.

0002

2. Description of the Related Art FIG. 5 is a front sectional view of a conventional image reading device. Reference numeral 100 denotes a hollow reading device main body, and an original table glass 103 is provided on the upper surface of the reading device main body 100, while a reading means 104 is provided inside thereof. The reading unit 104 includes a lamp scanning unit 105 and a mirror scanning unit 106 that are movable in a predetermined direction within the reading device main body 100, that is, in a direction A parallel to the document table glass 103, and an image sensor 108 fixed to the machine frame 107. It is composed of:

The reading means 104 has a home position Q shown by a solid line and a reading start position shown by a two-dot chain line, that is, A.
There is a DF position R. Lamp scanning unit 105
The mirror scanning unit 106 is moved by a drive source (not shown). Further, as a means for stopping the lamp scanning unit 105 and the mirror scanning unit 106 at the ADF position R, a detection sensor 109 for detecting the lamp scanning unit 105 is disposed within the reading device main body 100. Furthermore, although not shown, assuming that the ADF position R is from the home position Q of the reading device main body 100, the ADF position R is determined by the number of pulses of the pulse motor as the drive source.
A means of setting the value is also adopted.

On the other hand, on the top surface of the reading device main body 100, there is a feeding means, ie, an automatic document feeding device, for feeding the document to a predetermined position with its edge aligned with a size indicator (not shown) on the document table glass 103. 110 is installed. The automatic document feeder 110 can be opened and closed via a bracket 111 and a hinge 112. In addition, the automatic document feeder 1
10 includes a document stacking tray 113, a feeding roller 114, a conveyance roller 115, a conveyance guide 116, and the like.

In the above configuration, the document loading tray 113
While feeding the upper original onto the original platen glass 103,
While moving the reading means 104 in the ADF position R in the direction of arrow A, the original is illuminated with a lamp L, and the reflected light H is guided to the image sensor 108 to optically read the image of the original.

[0006]

[Problems to be Solved by the Invention] However, in the above conventional example, the reading device main body 100 and the automatic document feeder 11
Regardless of the positional relationship with 0, the home position Q in the reading device main body 100 is used as the setting standard for the ADF position R. Therefore, if the mounting position (horizontal direction in the figure) of the automatic document feeder 110 with respect to the main body 100 of the reading device is poor, the document fed onto the document platen glass 103 and the
An error occurs in the positional relationship with the DF position R along the moving direction of the reading means 104.

As a result, when reading a document, the leading edge of the document cannot be read in the image information of the document, or the trailing edge of the document cannot be read. This results in deterioration.

[0008] The present invention is intended to solve the above-mentioned problems, and provides an image reading device in which the reading start position of the reading device can be set in accordance with the mounting position of the feeding device with respect to the main body of the reading device. It is an object.

[0009]

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a reading device main body and a feeding means attached to the reading device main body for feeding a document to a predetermined position of the reading device main body. In the image reading device, the reading device is provided with a reading means for optically reading an image of a document fed to a predetermined position by moving in a predetermined direction from a reading start position. A reading start position reference is provided in the means, and the reading start position is read by the reading means to set the reading start position.

0010

[Operation] In the present invention based on the above configuration, the reading means reads the reading start position reference and sets the reading start position in the moving direction of the reading means in correspondence with the mounting position of the feeding means with respect to the main body of the image apparatus.

[0011] When the original is fed to a predetermined position on the main body of the reading device by the feeding means, the reading means moves in a predetermined direction from the reading start position and optically reads the image of the original.

0012

Embodiment Next, the structure of the present invention will be explained based on FIGS. 1 and 2. FIG. 1A is a front sectional view showing the main parts of a feeding means, that is, an automatic document feeder (hereinafter referred to as ADF) 80, and FIG. 1B is an external perspective view of the image reading device. Further, FIG. 2 is a front sectional view showing the image reading device.

On the upper surface of the internally hollow reading device main body 81,
A document table glass 3 is provided horizontally, and a reading means, that is, an exposure scanning means 4 is provided therein. The exposure scanning means 4 is operated in a predetermined direction, that is, on the document table glass 3.
a lamp scanning unit 5 that is moved in the B direction parallel to the
It consists of a mirror scanning unit 6 and an image sensor 2 fixed to the machine frame 2. Lamp scanning unit 5
includes an illumination lamp L as a light source that illuminates the original P, and a first mirror M1 that reflects the image reflected light from the original surface irradiated by the lamp L toward the mirror scanning unit 6 side.

On the other hand, the mirror scanning unit 6 is provided with a second mirror M2 and a third mirror M3 that return the image light reflected by the first mirror M1 toward the image sensor 1. Further, the mirror scanning unit 6 is configured to move at 1/2 the speed of the lamp scanning unit 5 based on the principle of a movable pulley, without changing the optical path length. The mirror scanning unit 6 scans parallel to the optical axis while maintaining a right angle to the optical axis of the lens 82 of the machine frame 2, and the second and third mirrors M2 and M3 are supported by a support member (not shown). ing.

On the document platen glass 3, there is a size index S for indicating the size of the document and for making it easy to set the document in a predetermined position by abutting the edge of the document. It is provided. In addition, the back side (bottom side in the figure) of the size index S is white, and by reading this, shading is performed to correct for variations in the light amount distribution of the illumination lamp L, variations in the sensitivity of the light receiving part of the image sensor 1, etc. The correction is performed during the book mode in which the exposure scanning means 4 scans and reads.

On the other hand, the ADF 80 is attached to the upper surface of the reading device main body 81. ADF80 is the reading device main body 81
The ADF 80 is attached to a bracket 83 by a hinge 23 so as to be openable and closable, and when scanning an original by scanning the exposure scanning means 4 of the reading device main body 81, the ADF 80 is attached to a bracket 83 using the hinge 23 as a fulcrum as shown by a chain double-dashed line. , and you can set the original.

Reference numeral 7 denotes a pickup roller that picks up the document P placed on the document stacking tray 8 . 9 is a paper feed roller, 10 is a separation roller, and the separation roller 10 is urged against the paper feed roller 9 with a constant pressure. The separation roller 10 is configured to constantly rotate in the original return direction D.
Furthermore, the transmitted torque is regulated by a torque limiter. The transmitted torque is set to be smaller than the frictional force between the paper feed roller 9 and the original P, and larger than the frictional force between the originals P.

In other words, the separating roller 10 follows the original P when only one original P is run up, and when two or more originals P are run up, the separation roller 10 follows the run-up of two or more originals P by the torque force of the torque limiter. The documents P are sent back to the document stacking tray 8 in order from the lowest document. Therefore, only the uppermost document is separated from the document P, and the paper feed roller 9 and separation roller 10
to be delivered.

A conveying roller 12 is downstream of the conveying roller 11.
Further, a paper discharge roller 13 is disposed, and pinch rollers 14, 15, and 16 are pressed against each other. Also,
A document edge detection sensor 17 is provided between the path of the document from the conveyance roller 11 to the conveyance roller 12, and a document discharge sensor 18 is provided near the document discharge roller.
A document detection sensor 19 is disposed at a position facing each other.

The lower document guide 20, which forms a path for the document, is made of a transparent sheet member in order to read the document from below. In addition, since the upper original guide 21 that forms a passage for the original together with the lower original guide 20 needs to read transparent originals such as OHP sheets as originals, the lower surface of the upper original guide 21 (original passing surface) is white. This white surface is used as a white reference during shading correction in the reading mode (ADF mode) of the ADF 80.

The feature of this embodiment of the present invention is that the ADF
A marker 90 serving as a reading start reference indicating the original reading start position (ADF position) is provided outside the original reading area in the main scanning area at the time, that is, on the lower surface of the lower original guide 20. A window W is provided at a position corresponding to the size index S and the marker 90.

Therefore, the image sensor 1 is set so that its readable area in the main scanning direction (direction perpendicular to arrow B) can read up to the position of the marker 90 on the ADF in addition to the reading width of the document. .

FIG. 3 is a block diagram showing the main circuit configuration of the present invention. The reading device main body 81 is provided with a CPU circuit 50, which is connected to a lamp regulator circuit 85 that turns on and off the illumination lamp L. In addition, the CPU circuit 50
is connected to the image sensor 1 via a drive circuit 86. Further, the CPU circuit 50 is connected to a main body drive source SM1 that moves the reading means 4.

On the other hand, the ADF 80 has a document detection sensor 19.
, document edge detection sensor 17, document discharge sensor 18 and AD
An ADF drive circuit 87 connected to the F drive source SM2 is provided. This ADF drive circuit 87 includes the CPU circuit 50
It is connected to the. The CPU circuit 50 is connected to external equipment (image recording section, etc.).

Next, the operation of this embodiment will be explained. Manuscript P
When the document P is set on the document stacking tray 8, the document detection sensor 19 detects the document P, and this detection signal is sent to the document tray 8.
The signal is sent to the U circuit 50. Upon receiving this signal, the CPU circuit starts setting the ADF mode when a document reading command is output to the CPU circuit 50 from an external device connected to the reading device main body 81.

A drive command is issued from the CPU circuit 50 to the drive source SM1, and the exposure scanning means 4 starts moving from the home position X to the ADF position Y. After moving the exposure scanning means 4 a predetermined number of lines, while further moving the exposure scanning means 4 on the white reference area on the back side of the size index S,
At the same time, reading is performed by the main body image sensor 1. The number of read bits of the image sensor 1 is set so that the area read by the image sensor 1 is the area of the window W provided in the size index S.

Therefore, in this area, the image sensor 1 detects the position where the marker 90 indicating the ADF position Y of the ADF 80 changes from white on the back side of the body size index S to black.
This detection signal causes the CPU circuit 50 to
A drive stop command is issued to the main body drive source SM1, and the exposure scanning means 4 stops at an accurate reading start position in the direction of arrow B.

In this state, the illumination lamp L is turned on, the white color of the document passing surface of the document upper guide 21 is read, and shading correction data is taken into the CPU circuit 50. Thereafter, the apparatus enters a standby state with the illumination lamp L turned on until the document P is conveyed. Here, A of the reading device main body 81
DF mode setting is completed.

On the other hand, when a document reading command is output from an external device connected to the reading device main body 81 to the CPU circuit 50, the CPU circuit 50 issues a drive command to the drive source SM2, thereby causing the pickup roller 7 to swing. A moving mechanism (not shown) presses the uppermost document P on the document stacking tray 8 and runs toward the paper feed roller 9 . The document P that has been run up is separated by a paper feed roller 9 and a separation roller 10 so that only the uppermost document is separated and fed.

When the leading edge of the document P is detected by the document edge detection sensor 17, this detection signal is sent to the CPU circuit 50, and the position where the drive source is driven for a predetermined period of time in response to this detection signal is determined as the reading start position. It has been set. Therefore, the manuscript P
is transported by the transport rollers 11 and 12 after its leading edge is detected by the document end detection sensor 17, and after the predetermined time elapses, a document reading command is issued from the CPU circuit 50, and the exposure scanning means 4 and the image sensor 1, the ADF 80 sequentially transports the original P while scanning is performed.

The read image signal (analog signal) is input to an A/D converter and converted into a digital signal of predetermined bits. The converted signal undergoes shading correction, is subjected to image processing in an image processing section, and is then output to an external device.

When the document P is sequentially read and the trailing edge of the document P is detected by the document edge detection sensor 17, the document P is read for a predetermined time according to the detection signal, and then the document P is read. The reading is completed and the illumination lamp L is turned off. The ADF 80 transports the original P that has been read using the paper ejection roller 13, and when the trailing edge of the original P is detected by the original ejection sensor 18, the ADF 80 further transports the original P for a predetermined period of time, and then transfers the original P onto the original ejection tray 22. Drain and stop.

Based on the document detection signal of the document detection sensor 19, it is determined whether or not the document P is stacked on the document stacking tray 8. If the document P is stacked on the document stacking tray 8, the CPU circuit A document feed signal is output from 50, and the above-described reading of the document P is repeated. When the reading of the last document P on the document stacking tray 8 is completed, the CPU
A drive command is issued from the circuit 50 to the drive source SM1, and the exposure scanning means 4 moves to the home position X, completing all operations.

FIGS. 4A and 4B show a second embodiment. The feature of this second embodiment is that a window W' is provided in a part of the main body size index S' parallel to the original reading main scanning line, and a window W' is provided in the conveyance guide 92 of the ADF 80 facing the window W'.
A marker 91 is provided to indicate the reading start position reference. The rest of the configuration is similar to that of the first embodiment.

The operation of the second embodiment will be explained below. When the original P is set on the original stacking tray 8, the original P is detected by the original detection sensor, and this detection signal is sent to the CPU circuit 50. Upon receiving this signal, the CPU circuit 50 starts setting the ADF mode when a document reading command is output from the external device to the CPU circuit 50. Then, a drive command is issued from the CPU circuit 50 to the drive source SM1, and the exposure scanning means 4 moves from the home position to the ADF.
Start moving into position. After moving the exposure scanning means 4 by a predetermined number of lines, the white reference area on the back side of the size index S' is read by the image sensor 1 while the exposure scanning means 4 is further moved.

The number of read bits of the image sensor 1 is set so that the area read by the image sensor 1 is the area of the window W' provided in the size index S'. Therefore, in this area, from the white color on the back side of the size index S',
The image sensor 1 detects the position where the marker 91 indicating the ADF position of the DF changes to black, and based on this detection signal, the CPU circuit 50 sends a signal from the ADF marker 91 to the predetermined document reading start position (ADF position Y) from the CPU circuit 50 to the drive source SM1. After a drive command is issued to move the exposure scanning means 4 to the ADF position Y, a drive stop command is issued, and the exposure scanning means 4 stops at the correct reading start position. In this state, the illumination lamp L is turned on, the white color of the document passing surface of the document upper guide 21 is read, and shading correction data is taken into the CPU circuit 50.

After that, with the illumination lamp L turned on,
It is in a standby state until the document P is conveyed from the DF 80. At this point, the ADF mode setting of the main body of the reading device is completed. After the ADF mode is set, the paper feeding, conveyance, and paper ejection operations of the ADF 80 and the image reading operation of the reading device main body 81 are performed in the same manner as in the first embodiment.

The difference between the second embodiment and the first embodiment is as follows. In the first embodiment, the readable area of the image sensor 1 in the main scanning direction is the reading width of the document and the ADF.
Although the reading width of the marker 90 indicating the reading line of 80 is required, in this embodiment, since the marker 91 indicating the reading line of the ADF 80 can be configured within the reading width of the original, it is only necessary to have the reading width of the original. Therefore, the second embodiment is effective when there is no margin in the readable area of the image sensor 1 in the main scanning direction.

In the first and second embodiments described above, A
Although the color of the marker provided on the component of the DF is black, this is not the case as long as the color can be distinguished from the white color on the back side of the size index by the image sensor of the main body.

In this way, in both the first and second embodiments, the ADF position Y of the exposure scanning means 4 can be set corresponding to the mounting position of the ADF 80 with respect to the reading device main body 81. Therefore, accurate image reading operation can be performed regardless of the accuracy with which the ADF 80 is attached. Also,
Since mounting accuracy is not required, it can be manufactured at low cost.

Although the above embodiment is applied to a scanner, it can also be applied to a copying machine, a facsimile machine, etc.

[0042]

As described above, in the present invention, the reading start position of the reading means can be set in accordance with the mounting position of the feeding means with respect to the main body of the reading apparatus. Therefore, the image of the document fed from the feeding means to a predetermined position on the reading apparatus main body can be accurately read regardless of the accuracy with which the feeding means is attached to the reading apparatus main body.

[Brief explanation of drawings]

FIG. 1 (A) is a front cross-sectional view showing essential parts of an automatic document feeder according to a first embodiment of the present invention, and (B) is an external perspective view of the same embodiment.

FIG. 2 is a front sectional view showing the overall configuration of the first embodiment of the present invention.

FIG. 3 is a block diagram showing the main circuit configuration in the first embodiment of the present invention.

FIG. 4(A) is a front sectional view showing essential parts of an automatic document feeding device according to a second embodiment of the present invention, and FIG. 4(B) is an external perspective view of the same embodiment.

FIG. 5 is a front sectional view showing the overall configuration of a conventional image reading device.

[Explanation of symbols]

4 Exposure scanning means (reading means) 80 Automatic document feeding device (feeding means) 81 Reading device main body 90, 91 Marker (reading start position reference) P Original

Claims (1)

[Claims] 1. A reading device main body, and a feeding means attached to the reading device main body for feeding a document to a predetermined position of the reading device main body, the feeding means being attached to the reading device main body from a reading start position In an image reading device provided with a reading means for optically reading an image of a document fed to a predetermined position by moving in a predetermined direction, a reading start position reference is provided in the feeding means, and the reading start position reference is An image reading device configured to read the image by the reading means to set the reading start position.