JPH09102850A - Image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the step out of a stepping motor in the case of reading and scanning image data of a position-fixed reading original by the back and forth movement of a reading scanning device with simple structure. SOLUTION: The number of driving pulses of the stepping motor 9 is counted at the time of feed back of the reading scanning device 10, the number of driving pulses of the stepping moors 9 in the forward direction is compared with the one in the backward direction, and the occurrence of step out in the stepping motor 9 is decided when the comparison result deviates from a permission range. The step out of the stepping motor 9 is detected by comparing the driving pulses, so that any exclusive components such as a rotary encoder etc. are not required for the detection of the step out.

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 for reading and scanning image data from a read original.

[0002]

2. Description of the Related Art Image reading devices such as image scanners are currently used. In such an image reading device,
There are a document fixing method that moves the reading scanning device in the sub-scanning direction while the reading document is fixed, and a document conveyance method that moves the reading document in the sub-scanning state while the reading scanning device is fixed. Some products run by.

In a fixed original type image reading apparatus, a contact glass on which a read original is fixedly placed is generally provided on the upper surface of the main body of the apparatus, and a reading / scanning apparatus is provided below the contact glass. ing. This reading / scanning device generally uses a stepping motor as a drive source, and reciprocates in a sub-scanning direction at a position facing the contact glass. There are two types of reading and scanning devices that directly reciprocate the line sensor, and those that fix the line sensor and reciprocally move the reflection optical system.

When the image data of a read original is read and scanned by such an image reading device, the reading and scanning device driven by the stepping motor reciprocates in the sub-scanning direction at a position facing the contact glass, and in the forward path. Image data is read and scanned. At this time, the forward scanning range of the reading scanning device is controlled by the number of drive pulses of the stepping motor, so that the reading scanning device is prevented from moving to a position where no document is read. When this forward scanning is completed, the stepping motor is rotated in the reverse direction and the scanning device returns. Therefore, when the home position sensor detects that the scanning device has returned to the home position, the driving of the stepping motor ends. To do. It should be noted that the forward drive of the reading / scanning device is executed at a low speed because of the relationship of the image data reading process and the drive control of the stepping motor, but the backward movement is executed at a high speed to quickly return to the initial state. .

In such an image reading apparatus, read and scanned image data is temporarily stored in an image memory and then transmitted to a host computer. In such a case, the image memory is temporarily full. Sometimes. In such a case, if the reading scan is continued as it is, image data is lost due to overflow, so the reading scan is switched to the intermittent reading. In this intermittent reading, the interruption and the resumption of the reading scanning are repeated, so that the reading rate of the image data is lowered and the overflow of the image memory can be prevented.

[0006]

In the image reading apparatus as described above, the reading / scanning apparatus is driven by the stepping motor. However, the stepping motor sometimes suffers step-out in which the rotation speed fluctuates. If the step-out occurs during the reading scanning, the image data becomes defective. In particular, when the intermittent reading as described above is executed, the stepping motor is repeatedly stopped and started, so that step-out is likely to occur.

In order to detect the occurrence of this defect, a rotary encoder is usually mounted on the stepping motor, and the rotation speed of the stepping motor is constantly monitored. However, this requires the provision of a rotary encoder or the like, which increases the number of parts of the image reading apparatus, which hinders reduction in size and weight and improvement in assembly.

Further, in the image reading device disclosed in Japanese Patent Laid-Open No. 4-336854, black and white marks are formed at equal intervals on the side of the contact glass, and this is read and scanned by the reading scanning device together with the read document. . When the reading / scanning speed changes, the black-and-white mark reading interval also changes. By monitoring this, it is possible to detect step-out of the stepping motor.

In this case, a complicated part such as a rotary encoder is unnecessary, but it is still necessary to form a black and white mark. Further, in order to read and scan the black-and-white mark together with the image data, it is necessary to laterally extend the reflective optical system and the line head, which also hinders reduction in size and weight of the image reading apparatus and improvement in productivity.

[0010]

According to the first aspect of the present invention,
When the reading / scanning device is reciprocally moved by the stepping motor to read and scan the image data of the read document, the forward scanning range of the reading / scanning device is set by the number of drive pulses of the stepping motor, and the backward path of the reading / scanning device is set. In the image reading apparatus that executes the stop of the return movement of the reading scanning apparatus according to the detection of the home position sensor, a pulse accumulating unit that counts the number of driving pulses of the stepping motor when the reading scanning apparatus returns is provided, and There is provided pulse comparison means for comparing the number of drive pulses of the stepping motor with the return path, and step-out determination means for determining the occurrence of step-out of the stepping motor if the comparison result deviates from the allowable range. Therefore, step-out of the stepping motor can be detected by comparing the drive pulses, it is not necessary to add a rotary encoder or a black and white mark, and it is not necessary to laterally extend the reflection optical system or the line head.

According to a second aspect of the present invention, in the first aspect of the present invention, the image discarding means for invalidating the image data read and scanned by the reading / scanning device when the out-of-step determining means determines that out-of-step has occurred. Therefore, when a reading failure occurs in the image data due to stepping out of the stepping motor, the image data is invalidated.

According to a third aspect of the present invention, in the first aspect of the invention, there is provided defect notification means for notifying and outputting a defective reading of image data when the step-out determination means determines that the step-out has occurred. Therefore, when a reading failure occurs in the image data due to stepping out of the stepping motor, the occurrence of the reading failure is notified and output to the user.

According to a fourth aspect of the present invention, in the third aspect of the present invention, operation input means for accepting an input operation for validating or invalidating the image data in a state in which the fault notifying means outputs the faulty reading is provided. An image manipulating means is provided for executing invalidation or validity of the image data corresponding to the input operation.
Therefore, the user selects invalidity or validity of the image data in a state where the user is notified and output of the image data reading failure due to the stepping motor step-out.

According to a fifth aspect of the present invention, in the first aspect of the invention, when the out-of-step determining means determines that out-of-step has occurred, the scanning range of the reading scanning device corresponding to the number of drive pulses counted by the pulse integrating means. An image cropping means is provided for validating the image data only. Therefore, even if a reading failure occurs in the image data due to stepping out of the stepping motor,
The image data read and scanned before the occurrence of step-out is valid.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, an intermittent determination means is provided for determining whether or not the intermittent scanning is necessary to repeat the interruption and the resumption of the scanning during the execution of the scanning for reading. When the necessity of reading is judged, the reading intermittent means for controlling the scanning operation to execute the intermittent reading is provided, and the reading judging means for judging whether the intermittent reading is executed or not when the step-out judging means judges the occurrence of the step-out. An image discarding unit that invalidates the image data when the execution of the intermittent reading is determined is provided. Therefore, if intermittent reading is not executed even if it is determined that the stepping motor is out of step, the image data that has been read and scanned by the time when the stepping occurs is valid, and it is determined that the stepping motor is out of step and intermittent reading is performed. Is executed, all the image data is invalidated.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. First, as shown in FIG. 3, an image reading system 100 exemplified here as an image reading apparatus includes an image scanner 101 and a host computer 10 as shown in FIG.
2 is connected to the structure.

As shown in FIG. 1, the image scanner 101 has a contact glass 1 on which a document to be read is placed. At a position facing the contact glass 1 from below, a reflection mirror 2 and an illumination are provided. The first traveling body 4 having the lamp 3 mounted thereon is arranged so as to be movable in the sub-scanning direction. In the reflection optical path of the first traveling body 4, a second traveling body 5 whose optical path is folded back by two reflection mirrors 2 is movably arranged in the sub-scanning direction. To the SBU (Sensor Board) via the imaging lens 6.
Unit) 7 CCD (Charge Couple)
d Device) 8 is located.

A traveling body motor 9 composed of a stepping motor is connected to the first traveling body 4 and the second traveling body 5 by a pulley, a wire or the like, and at a speed of 2: 1 and in the same sub-scanning direction. It is supposed to be movable. As the two traveling bodies 4 and 5 move in this way, the read image of the read original placed on the contact glass 1 is read and scanned by the CCD 8 in the sub-scanning direction, and thus the read scan is performed here. A device 10 is formed.

As will be described later in detail, the reading scanning of the read original by the reading scanning device 10 is executed under the setting of the book mode which is the original fixed mode. In addition to the book mode described above, the ADF mode, which is a document transport mode, is also set as a switchable operation mode. Under the setting of the ADF mode, as shown by the broken line at the right end of the figure, the two traveling bodies 4 and 5 are arranged at the home position,
The ADF 11, which is a document transport device, sequentially transports the read document in the sub-scanning direction and scans the image data.

The ADF 11 has a paper feed tray 12, a pickup roller 13, a pair of registration rollers 14, a conveying drum 15, and a plurality of conveying rollers 16, and sequentially conveys a read document in the sub-scanning direction and discharges the sheet. The tray 17 is made to discharge the paper. The paper discharge tray 17 is formed on the upper surface of a document pressure plate 18, and the document pressure plate 18 is provided on the contact glass 1 so as to be openable and closable. A sheet feeding motor 19 including a stepping motor is connected to the pickup roller 13 and the registration roller 14 of the ADF 11 by a gear train or the like, and the conveying drum 15 and the conveying roller 1 are connected.
A conveyor motor 20 composed of a stepping motor is connected to 6 by a gear train or the like.

In addition, below the inside of the image scanner 101, a unit substrate which constitutes an electric system described later is built in. Therefore, such an image scanner 101
The block structure of the electric component system will be described below based on FIGS. 2 and 3 together with its function.

First, the reflected light of the read original incident on the CCD 8 on the SBU 7 is converted into analog image data having a voltage value according to the intensity of the light in the CCD 8 and divided into odd bits and even bits. MBU (Mother Board
Unit) 21 is sequentially output. In the MBU 21, the dark potential part is removed by an AHP (Analog data Handling Peripheral) 22, the odd bits and the even bits are combined, and the gain is adjusted to a predetermined amplitude, and then the A / D
(Analog / Digital) converter 23 inputs and digitizes.

The image data digitized by the MBU 21 is SCU (Scanner Control) as will be described later in detail.
SIP3 (Scann) which is a data binarization unit on the Unit 24.
The er Imaging Peripheral 3) 25 performs shading correction, gamma correction, MTF correction, etc., and then performs binarization processing. This binarized image data is
It is output as video data together with the page sync signal, line sync signal, and image clock. In addition, this SIP
325 does not binarize the image data depending on the operation mode, but outputs it as video data together with a page sync signal, a line sync signal, and an image clock.

The video data output from the SIP3 25 is sent to the IEU (Image
Enhance Unit) 27. As will be described later in detail, the IEU 27 determines the video data into character data and picture data by a predetermined image processing, and outputs the video data to the SCU 24 together with the determination result. The video data output to the SCU 24 again is input to the selector 28. This selector 28 has the other input connected to the SI.
The video data from P325 is provided, and it is configured so that it can be selected whether or not the image processing by the IEU 27 is performed.

The output of this selector 28 is the RCU (River
The input from the se side control unit) 29 is input to the selector 30 which has one input, and is configured so that the reading surface of the read document can be selected. The RCU 29 is an optional unit for controlling the reading and scanning of the back side of the read document when reading and scanning both sides of the read document, and is a CPU (Cen) which is a central processing unit in the SCU 24.
The image data of the back surface scanned and read is transferred as video data to the SCU 24 via the MBU 21 under the control of serial communication by the tral processing unit 31.

The video data output side of the selector 30 is connected to the selector 32 and the connector 33, and the other input of the selector 32 is the video data from the video adapter 34. As a result, the video adapter 34 can be connected to the end of the connector 33. On the other hand, the video data output of the selector 32 is SBC (Sea).
n Baffer Controller) 35. Therefore,
The video data output from the SIP3 25 and input to the SBC 35 is DRAM (Dynamic Random Ac
cess Memory) 36 and optional additional RAM (Random Ac
SIMM (Single Inline Memory Mo)
dule) and 37.

Further, the connector 38 has a DCU (Data Compression Unit) for compressing the input image data.
39 is connected. The image data compressed by the DCU 39 is input to one input of the selector 40 of the SCU 24, and is configured to select whether to compress the image data. The image data output from the selector 40 is a SCSI (Small C) functioning as a data communication processing unit.
data is transferred to the host computer 102 (not shown) via the computer system interface controller 41.

On the SCU 24, CPU 31, EP
ROM (Erasable Programmable ROM) 42, RAM 43
Is installed and operates so as to control the SCSI controller 41 and communicate with the host computer 102. A control program for the CPU 31 and the like are fixedly stored in advance in the EPROM 42.
M43 temporarily stores various data of the processing operation of the CPU 31. That is, the CPU 31 uses the EPROM
According to the storage data of 42, various processing operations are executed using the storage area of the RAM 43. For example, the CPU 31 controls the driving pulse of the traveling body motor 9, the paper feeding motor 19, and the conveyance motor 20 to control the operation timing of the reading and scanning device 10 and the ADF 11. Further, the ADU (ADF Driving Unit) 44 connected to the MBU 21 is
The power supply of the electrical components used for 11 is relayed.

An operation panel 45 having a keyboard and a display is provided on the outer surface of the image scanner 101, and the operation panel 45 is also the CP.
Connected to U31. Various sensors 46 to 51 are provided at optimum positions inside the device of the image scanner 101, and these sensors 46 to 51 are also connected to the CPU 31.

A document presence / absence sensor 46 is provided on the paper feed tray 12 to determine the presence / absence of a document to be read. Similarly, the conveyance sensor 47 detects the start of conveyance of the read document, and the double feed detection sensor 48 detects the double feed of the read document whose conveyance has started. The reading position sensor 49 detects that the read document being conveyed has reached the reading position, and the paper discharge sensor 50 detects that the read document that has been read and scanned is discharged. An HP (Home Position) sensor 51 is arranged at the home position of the reading / scanning device 10, and detects the first traveling body 4 of the reading / scanning device 10 at the home position.

On the other hand, the host computer 102 is
An I / F (Interfa) that consists of a general microcomputer and communicates various data with the image scanner 101.
ce), a device main body for realizing various data processing, a keyboard for inputting and operating various data, a display (not shown) for displaying and outputting various data, and the like.

In the image scanner 101 described above, the reading and scanning operation modes are set to the book mode and the A mode by an external input from the operation panel 45 or the host computer 102.
It can be set to switch to DF mode. Under the setting of the book mode which is the original fixing mode, the image data of the read original placed on the contact glass 1 is read in the sub scanning direction by the reading scanning device 10 which moves the traveling bodies 4 and 5 in the sub scanning direction. To be scanned. Document transport mode A
When the DF mode is set, the image data of the read document sequentially conveyed in the sub-scanning direction by the ADF 11 is read and scanned by the reading and scanning device 10 in which the traveling bodies 4 and 5 are fixed.

When the image scanner 101 scans and scans the image data of the read original as described above, this image data is temporarily stored in the DRAM 36 or SIMM 37 and then serially transmitted to the host computer 102 by the SCSI controller 41. It Although such scanning and scanning of image data, temporary storage, and transmission are continuously and sequentially executed, the processing of each unit may actually be delayed.
Therefore, during execution of the read scan by the read scan device 10 or the ADF 11, the CPU 31 causes the DRAM to operate.
36 and the operation of the host computer 102, and when a delay in the processing is detected, in order to prevent the overflow of the image data, the reading and scanning device 10 and the ADF 11 are suspended and restarted. It is repeated and intermittent reading is executed.

Here, the image reading system 100 described above is used.
Has an intermittent judgment means and a reading intermittent means. The intermittent judgment means judges whether or not the intermittent reading is necessary during the execution of the reading scanning, and the reading intermittent means judges that the intermittent reading is necessary. Then, the scanning operation is controlled and the intermittent scanning is executed.

In the image reading system 100 described above, the image data read and scanned from the original read by the image scanner 101 is transferred to the host computer 10.
However, it takes much time to read and scan such image data. Therefore, when the scan range is set by the host computer 102, the image scanner 101 scans and scans the read original within the set scan range, thereby preventing unnecessary scan and transmission of image data.

Therefore, the image scanner 101
When the reading / scanning device 10 is reciprocally moved by the traveling body motor 9 to read and scan the image data of the read document, the forward scanning range of the reading / scanning device 10 depends on the number of drive pulses of the traveling body motor 9. Control. That is, when the scanning range is set by the host computer 102, the CPU 31 sets the number of drive pulses of the traveling body motor 9 corresponding to the scanning range in the RAM 43. In this state, the traveling body motor 9 drives the reading / scanning device 10 to read and scan image data, and the number of drive pulses of the traveling body motor 9 on the outward path is counted by the CPU 31 which is a pulse counter. . If the measured value of this drive pulse matches the set value,
When the reading scanning device 10 determines that the reading scanning is completed, the traveling body motor 9 is stopped.

When the reading scanning of the reading scanning device 10 in the forward path is completed, the reading scanning device 10 starts the return movement of the returning path, but this is not controlled by the driving pulse of the traveling body motor 9, and It is managed by the detection of the HP sensor 51. That is, as described above, the reading scanning device 10
When the read scan of the forward path is completed, the CPU 31 reverses the traveling body motor 9 to return the reading scanning device 10, but the first traveling body 4 of the reading scanning device 10 returns to the home position. The HP sensor 51
Then, the return movement of the reading / scanning device 10 by the reverse drive of the traveling body motor 9 is completed. The return movement of the reading / scanning device 10 is performed at high speed within a mechanically reasonable range because the reading / scanning of image data is not executed.

As described above, the reciprocating movement of the reading and scanning device 10 is executed by the traveling body motor 9, but the traveling body motor 9 may be out of step. In order to detect such a step-out of the traveling body motor 9, the above-described image reading system 100 has a pulse integration means, a pulse comparison means, and a step-out determination means.

The pulse accumulating means is realized by utilizing hardware such as the CPU 31, the EPROM 42, the RAM 43, etc., and the reading / scanning device 10 completes the reading / scanning on the outward path and executes the returning movement on the returning path. When doing
The CPU 31, which executes the processing operation according to the data stored in the EPROM 42, executes the processing operation in which the number of drive pulses of the traveling body motor 9 is counted and temporarily stored in the RAM 43.

The pulse comparison means is also realized by utilizing the hardware such as the CPU 31, the EPROM 42 and the RAM 43, and the HP sensor 51 detects that the reading and scanning device 10 has completed the return movement. Then, a processing operation is performed in which the numbers of drive pulses of the traveling body motor 9 on the forward path and the return path of the reading and scanning device 10 are read from the RAM 43 and compared. At this time, the measured value is used for the number of pulses on the return path, but the set value by the host computer 102 is used for the number of pulses on the outward path.

The step-out determination means is also realized by utilizing the hardware such as the CPU 31, the EPROM 42, the RAM 43, etc., and the comparison result of the drive pulses of the reading scanning device 10 in the forward path and the backward path is obtained as a difference. It is calculated as an absolute value, and if it deviates from the permissible range preset in the RAM 43, a processing operation for determining out-of-step occurrence of the traveling body motor 9 is executed.

Further, the image reading system 100 exemplified here has an image discarding means for invalidating the image data when it is judged that the running motor 9 is out of step as described above. This image discarding means is the CPU 31
When the out-of-step determining unit determines that out-of-step occurs, the image data read and scanned by the reading scanning device 10 is read from the image scanner 101 by the image scanner 101. The processing operation is executed so that the image is not output to the host computer 102 but is erased inside the image scanner 101 to invalidate it.

With such a configuration, in the above-described image reading system 100, when the user manually operates the operation panel 45 of the image reading device or the keyboard of the host computer 102, the image scanner 101 according to various commands issued by the manual operation. Executes various operations such as mode switching and image reading.

For example, when it is desired to automatically feed a read document, a desired read document is loaded in the ADF 11, and the image scanner 101 is set to the ADF operation mode for reading and scanning by an input operation of the operation panel 45 or the host computer 102. Set the mode. When the scanning start is input after the scanning range is set by the operation panel 45 or the host computer 102 after this setting, the image scanner 101 drives the ADF 11 without traveling the traveling bodies 4 and 5 of the reading scanning device 10, The CCD 8 reads and scans the image data of the read document sequentially conveyed in the sub-scanning direction by the ADF 11. At this time, in the set scanning range, the conveyance speed of the read document is controlled to a constant speed that is optimum for the scanning scan of the CCD 8, and before and after the scanning range, the conveyance speed of the read document is controlled to the maximum speed that the ADF 11 can achieve. The reading scan is executed at high speed.

On the other hand, when manually feeding the read document as desired, the desired read document is placed on the contact glass 1 and the image scanner 101 is read and scanned by the input operation of the operation panel 45 or the host computer 102. Set the book mode as the operation mode. When the scanning start is input after the scanning range is set by the operation panel 45 or the host computer 102 after this setting, the image scanner 101 causes the traveling bodies 4 and 5 of the reading scanning device 10 to travel without driving the ADF 11. The reading and scanning device 10 reads and scans the image data of the read document in the sub-scanning direction. At this time, in the set scanning range, the scanning speed of the reading scanning device 10 is controlled to a constant speed that is optimal for reading scanning of the CCD 8, and before and after the scanning range, the scanning speed of the reading scanning device 10 is set to the maximum speed that the device can achieve. Since it is controlled, the read scan is executed at high speed.

The image data read and scanned in the book mode or the ADF mode described above is binarized by the SIP325, temporarily stored in the DRAM 36 or SIMM 37, and then serially transmitted to the host computer 102 via the SCSI controller 41. Is output. However, since the processing may be stagnant during the continuous execution of the reading scan, the temporary storage, and the transmission of such image data, as described above, whether or not the intermittent reading is necessary is performed during the reading scan. It is constantly monitored, and when a delay in processing is detected, the reading scan in execution is switched to intermittent reading.

For example, DRA for temporarily storing image data
When M36 becomes full, the full flag is set in response to this detection. Setting this full flag and DRA
When it is confirmed that M36 is in the full state, the reading scan in progress is interrupted. When the reading scan of the image data is interrupted in this manner, the DRAM 36 stops only the data input while the data output continues, and the full state is canceled and the empty state is set. When this empty state is detected, the full flag is released and the interrupted reading scan is restarted. By performing the intermittent reading as described above, even if the continuous processing of the image data is partially stopped, the reading scanning is controlled at a low speed correspondingly,
It is possible to prevent overflow of image data.

As described above, the image scanner 10
In the book mode 1, the reading / scanning device 10 is driven to read and scan the image data from the read document, but the running motor 9 driving the reading / scanning device 10 may be out of step. However, the image scanner 101 described above
The step-out of the traveling body motor 9 is detected from the drive pulse, and when the step-out is detected, the image data is invalidated, so that the image data of the reading failure is not output to the host computer 102.

Therefore, such an image reading system 10
The processing operation of 0 will be described below with reference to FIGS. First, as shown in the flowchart of FIG. 5, when the image reading is executed in the book mode, the image scanner 1
01 indicates the scanning range set by the host computer 102 as the number of drive pulses of the traveling body motor 9 R
It is set to AM43 (step S1). Reading scanning device 1
It is confirmed by the HP sensor 51 that the traveling bodies 4 and 5 of 0 are located at the home position (step S2). If this is not confirmed, the traveling bodies 4 and 5 are moved to the home position (step S3). In such a state, the reading and scanning of the reading and scanning device 10 by the forward rotation driving of the traveling body motor 9 is started, and at the same time, the counting of the driving pulse of the traveling body motor 9 is also started (step S4). The counted number of pulses is compared with the number of pulses set in the RAM 43 (step S5), and if they match, the traveling body motor 9
The driving of the reading and scanning device 10 is completed by (step S
6).

When the reading / scanning operation of the reading / scanning device 10 is completed, the number of pulses counted in the RAM 43 is reset (step S7). The return movement of the reading / scanning device 10 by the reverse rotation driving of the traveling body motor 9 is started, and at the same time, the counting of the driving pulse of the traveling body motor 9 is also started (step S8). When the HP sensor 51 detects the first traveling body 4 at the home position in such a state (step S9), the return movement of the reading scanning device 10 by the reverse driving of the traveling body motor 9 is completed, and at the same time, the traveling body motor 9 is detected. The driving pulse count of is also ended (step S10).

When the return movement of the reading and scanning device 10 is completed in this way, the number of pulses actually measured in the returning route is subtracted from the number of pulses set in the outward route of the reading and scanning device 10 and it is confirmed that this is smaller than the allowable range. (Step S11).
If this can be confirmed, it is determined that step-out has not occurred in the traveling body motor 9, and if it cannot be confirmed, the traveling body motor 9
Occurrence of step out is determined (step S12).

As shown in FIG. 6, the traveling body motor 9
The image data is output to the host computer 102 as valid only when it is not determined that the out-of-step has occurred, and the image data is invalidated and deleted when the out-of-step of the traveling body motor 9 is determined.

The details of the step-out determination as described above will be specifically described below. As shown in FIG. 4, the image scanner 1
The reading / scanning device 10 of 01 is "50 (m
When the reading scan starts at the position "m)" and ends at the position "470 (mm)", the scanning range is "470-50 = 4".
20 (mm) ". When the reading scanning is completed without the step-out of the traveling body motor 9, the number of drive pulses corresponding to" 470 (mm) "in the forward path and the backward path, for example, ,
When step-out occurs at the position of "300 (mm)" from the home position, the scanning range changes to "300-50 = 250 (mm)". In other words, the image data is not read and scanned up to the planned position, but in this case, the number of drive pulses of the traveling body motor 9 on the return path is the number corresponding to "300 (mm)".
This does not correspond to the initially set “470 (mm)”, and it is determined whether the traveling body motor 9 is out of step.

Since the above-mentioned image reading system 100 detects the step-out of the traveling body motor 9 by counting the driving pulse, it is not necessary to add a rotary encoder or a black and white mark, and the reflection mirror 2 and the CCD 8 are placed on the side. It is possible to detect out-of-step with a simple structure without the need for extension. In addition, the image data is invalidated when it is determined that the traveling body motor 9 is out of step, and thus it is possible to prevent the image data of the reading failure from being output to the host computer 102.

The image scanner 101 described above is used.
Drives the scanning unit 10 at high speed when returning,
Since step-out is unlikely to occur during this high-speed return, step-out is prevented on both the forward path and the return path of the reading and scanning device 10, and it is also prevented that the drive pulses of the traveling body motor 9 coincide with each other. Further, the image reading system 100 described above is
Although it has been illustrated that the image data is invalidated when it is determined that the traveling body motor 9 is out of step, the present invention is not limited to the above method and allows various modifications.

For example, the image reading system 100 may be provided with a defect notifying means, and as shown in FIG. 7, it is possible to notify and output the image data reading defect due to step out. Such a failure notification means is realized by using hardware such as the CPU 31 and the RAM 43. When it is determined that the out-of-step of the traveling body motor 9 is detected, the "read failure" preset in the RAM 43 has occurred. CP such as guidance
It is read by U31 and output from the image scanner 101 to the host computer 102. In this case, since the user is informed of the step-out that has occurred in the image scanner 101 by the display of the host computer 102, it is possible to output the image data to the host computer 102 regardless of the step-out determination of the traveling body motor 9. is there.

Further, the image reading system 100 is provided with an operation input means and an image operation means, and as shown in FIG. 8, inputting whether the image data is valid or invalid in the state in which the failure notification means outputs the failure to read. It is also possible to accept the operation by the operation input means and execute the image operation means to determine whether the image data is invalid or valid according to the input operation. The operation input means as described above is the keyboard of the host computer 102 or the operation panel 45 of the image scanner 101.
It is established by using hardware such as, and the operation panel 45 performs an input operation for validating or invalidating the image data in a state where the user is notified and output of the reading failure of the image data due to the step-out of the traveling body motor 9. Etc. The image scanning means as described above is realized by utilizing the hardware such as the CPU 31, and when the valid input is performed on the operation panel 45 or the like, the image data is output from the image scanner 101 to the host computer 102 and invalidated. Is input, the image data is erased inside the image scanner 101. In this case, the user can select whether the image data is invalid or valid in a state in which the user is informed and output of the poor reading of the image data due to the step-out of the traveling body motor 9.

Further, the image reading system 100 is provided with an image cutting means, and as shown in FIG. 9, when the out-of-step judging means judges that out-of-step occurs, the reading corresponding to the number of drive pulses counted by the pulse integrating means. It is also possible to validate the image data only in the scanning range of the scanning device 10. Such image cutting means is realized by utilizing hardware such as the CPU 31 and the DRAM 36. When it is determined that the running body motor 9 is out of step, the image data developed in the DRAM 36 is read and scanned. The CPU 31 reads only the scanning range of the feedback movement of the image scanner 1
01 to the host computer 102. In this case, even if the reading error occurs in the image data due to the step-out of the traveling body motor 9, the image data read and scanned before the step-out occurs can be used.

Furthermore, as described above, when the reading determining means and the image discarding means are added to the image reading system 100 equipped with the image cutting means, and as shown in FIG. It is also possible to determine whether or not the intermittent reading is performed by the reading determining unit, and invalidate the image data by the image discarding unit when the intermittent reading is determined. The reading determination means as described above includes the CPU 31 and the RAM.
This is established by using hardware such as 43, and when the occurrence of step-out is determined, the CPU 31 reads the operation history of the read scan from the RAM 43 and determines whether or not the intermittent read is executed. The image discarding means as described above is realized by utilizing the hardware such as the CPU 31, and when the execution of the intermittent reading is determined, the image data is invalidated and is erased inside the image scanner 101.

In this case, if the intermittent reading is not executed even if it is determined that the traveling body motor 9 is out of synchronization, the image data read and scanned by the time the out-of-synchronization occurrence is valid, and the traveling body motor 9 is out of synchronization. When the occurrence of the key is determined and the intermittent reading is executed, all the image data are invalidated. That is, step-out is likely to occur when the reading and scanning device 10 performs the intermittent reading. Therefore, if step-out occurs while the intermittent reading is performed, it is determined that the step-out occurs due to the intermittent reading. If the step-out occurs in the intermittent reading as described above, a reading failure occurs in the intermittently read portion of the image data, so that all the read and scanned image data are invalidated. Therefore, when a step-out occurs in the image scanner 101, it is possible to prevent only the image data having no reading failure from being output to the host computer 102, and prevent the reading failure image data from being output to the host computer 102.

[0061]

According to the first aspect of the present invention, there is provided pulse integration means for counting the number of driving pulses of the stepping motor when the reading / scanning device returns, and the number of driving pulses of the stepping motor on the forward and backward paths of the reading / scanning device. Stepping motor out-of-step can be compared by comparing drive pulses by having a pulse comparing means for comparing Can be detected without the need to add a rotary encoder or black and white marks,
It is not necessary to laterally extend the reflection optical system or the line head, and it is possible to detect the step-out of the stepping motor with a simple structure.

According to the second aspect of the present invention, by providing the image discarding means for invalidating the image data read and scanned by the reading / scanning device when the out-of-step determining means determines that out-of-step has occurred.
If a reading failure occurs in the image data due to stepping out of the stepping motor, the image data is invalidated, so that the use of the image data having the reading failure can be prevented.

According to the third aspect of the present invention, the step-out determining means is provided with the defect notifying means for notifying and outputting the image data read failure when the step-out determining means determines that the step-out has been detected by the stepping motor. When a defect occurs,
The user can be notified and output of the occurrence of the reading failure.

According to the fourth aspect of the present invention, operation input means is provided for accepting an input operation of valid or invalid of the image data in a state where the defective notification means outputs the defective reading and outputs the image data corresponding to the input operation. By providing the image operation means for executing invalidity or validity, it is possible to allow the user to select invalidity or validity of the image data in a state in which the user is notified and output of the poor reading of the image data due to stepping out of the stepping motor. You can

According to the fifth aspect of the present invention, when the out-of-step determining means determines that out-of-step has occurred, the image data which makes the image data valid only within the scanning range of the reading scanning device corresponding to the number of drive pulses counted by the pulse integrating means. By providing the cut-out means, even if the reading failure occurs in the image data due to the step-out of the stepping motor, the image data read and scanned by the step-out occurrence can be made effective.

According to the sixth aspect of the present invention, intermittent reading means is provided to judge whether intermittent reading is necessary to repeat interruption and resumption of reading scanning during execution of reading scanning, and it is judged that intermittent reading is necessary. The reading intermittent means for controlling the scanning operation to execute the intermittent reading is provided, and the reading judgment means for judging whether the intermittent reading is executed or not when the step-out judging means judges the occurrence of the step-out is provided. By providing the image discarding means for invalidating the image data, even if it is determined that the stepping motor is out of step, if the intermittent reading is not executed, the inside of the image data may be out of step due to the intermittent reading. Since no reading failure has occurred, it is possible to validate the image data that has been read and scanned before the occurrence of step-out, and if the stepping motor step-out occurrence is determined and intermittent reading is being executed, Since the internal data read failure due to loss of synchronism of the intermittent reading is occurring, it is possible to prevent the use of the image data of the defective read as invalid all the image data.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing an internal structure of an image scanner of an image reading system which is an embodiment of an image reading apparatus of the present invention.

FIG. 2 is a block diagram showing a circuit structure of an image scanner.

FIG. 3 is a block diagram showing a circuit structure of the image reading system.

FIG. 4 is a schematic diagram showing a positional relationship of reading scanning of the reading scanning device.

FIG. 5 is a flowchart showing an image reading processing operation of the image reading system.

FIG. 6 is a flowchart showing a processing operation for selecting valid / invalid of image data due to occurrence of step-out.

FIG. 7 is a flowchart showing a processing operation for notifying and outputting the occurrence of step-out as a first modified example.

FIG. 8 is a flowchart showing a processing operation for causing a user to select valid / invalid of image data due to step out as a second modified example.

FIG. 9 is a flowchart showing a processing operation of extracting an effective portion of image data due to out-of-step occurrence as a third modification.

FIG. 10 is a flow chart showing a processing operation for selecting validity / invalidity of image data upon occurrence of step-out according to presence / absence of intermittent reading as a fourth modified example.

[Explanation of symbols]

 100 image reading device 9 stepping motor 10 reading / scanning device 51 home position sensor

Claims (6)

[Claims] 1. When the reading / scanning device is reciprocally moved by a stepping motor to read and scan the image data of a read original, the forward scanning range of the reading / scanning device is set by the number of drive pulses of the stepping motor. In an image reading device that stops the return movement of the reading scanning device in the return path according to the detection of the home position sensor,
Provided is pulse integration means for counting the number of drive pulses of the stepping motor when the reading and scanning device returns, and pulse comparison means for comparing the number of drive pulses of the stepping motor on the forward and return paths of the reading and scanning device. An image reading apparatus is provided with a step-out determination unit that determines whether step-out of the stepping motor has occurred when the result of comparison deviates from an allowable range. 2. The image reading apparatus according to claim 1, further comprising image discarding means for invalidating the image data read and scanned by the reading / scanning device when the out-of-step determining means determines that out-of-step has occurred. 3. The image reading apparatus according to claim 1, further comprising defect notification means for notifying and outputting a read failure of the image data when the step-out determination means determines that the step-out has occurred. 4. An operation input means for accepting an input operation for validating or invalidating image data in a state where the fault notifying means outputs a faulty reading is provided, and whether the image data is invalid or valid is provided in response to the input operation. The image reading apparatus according to claim 3, further comprising image operation means for executing the operation. 5. An image cropping means is provided for validating the image data only in the scanning range of the reading scanning device corresponding to the number of drive pulses counted by the pulse accumulating means when the out-of-step judging means judges occurrence of step-out. Claim 1 characterized by the above-mentioned.
The image reading device according to claim 1. 6. An intermittent determination means for determining whether or not intermittent reading is necessary to repeat interruption and restart of the reading scanning during execution of the reading scanning is provided, and when the necessity of the intermittent reading is determined, the scanning operation is controlled. The reading intermittent means for executing intermittent reading is provided, and the reading judgment means for judging whether or not the intermittent reading is executed when the out-of-step judging means judges the occurrence of the out-of-step is provided. The image reading apparatus according to claim 5, further comprising an image discarding unit that invalidates the image.