JPH11239251A - Image reader and image reading method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader and image reading method in which occurrence of an image deviation is prevented. SOLUTION: In the case that residual capacity Rx of a buffer memory 109 is an optional prescribed value R2 or over (NO in step S209) and an optional prescribed value R1 or below (YES in step S212) and a change amount Tx in image data is a prescribed amount T1 or less (YES in step S214), a transport motor 108 is stopped and reading of the image data is interrupted (step S215), the image data are transferred from a buffer memory 109 to a host computer 110 to increase the idle residual capacity Rx of the buffer memory 109 (step S216). When the residual capacity of the buffer memory 109 reaches the prescribed value R1 or over (NO in step S212), image data of a succeeding line are read (step S206).

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 and an image reading method capable of preventing occurrence of image shift of a read image.

[0002]

2. Description of the Related Art A conventional image reading apparatus uses a buffer memory for storing image data read from a document to be read. When the buffer memory becomes full, control has been performed such that the transport of the read original is temporarily stopped, and after the buffer memory becomes empty, the transport of the original is started again and the reading operation is resumed.

[0003]

However, the conventional image reading apparatus described above cannot stop at the position where the document is to be temporarily stopped due to the inertia of the transport motor and the transport system, and the document overruns due to overrun. Shift occurs. Thereafter, when the conveyance motor is restarted and the reading of the document is resumed, the image data read due to the displacement of the document may be different from the original document, resulting in image displacement.

[0004] This image shift is particularly noticeable when reading an original with fine characters, and there has been a problem that a sentence cannot be read from the read image data.

Accordingly, an object of the present invention is to provide an image reading apparatus and an image reading method capable of preventing occurrence of an image shift in order to solve the above-mentioned problem.

[0006]

According to another aspect of the present invention, there is provided an image reading apparatus, comprising: an image reading unit that reads an image; and a moving unit that relatively moves the image and the image reading unit. A suspending means for suspending the moving means, a storing means for storing image data read by the image reading means, and a detecting means for detecting a remaining amount of storage capacity of the storing means and a change amount of the image. Means, and when the detecting means detects that the amount of free space in the storage capacity of the storage means and the amount of change in the image are respectively smaller than predetermined values, the suspending means controls the suspending means to suspend the moving means. Control means.

According to a second aspect of the present invention, in the image reading apparatus as set forth in the first aspect, after the suspending means temporarily suspends the moving means, the free remaining amount of the storage capacity of the storage means becomes the predetermined amount. When the detecting means detects that the value is equal to or more than the value, the moving means resumes the movement.

According to a third aspect of the present invention, there is provided the image reading apparatus according to the first or second aspect, wherein the detecting means detects that the remaining free space in the storage means is smaller than a predetermined value. The image forming apparatus further includes another storage unit that stores the image shift amount of the original moved before the temporary stop unit temporarily stops the moving unit.

According to a fourth aspect of the present invention, in the image reading apparatus of the third aspect, the predetermined value is zero.

According to a fifth aspect of the present invention, in the image reading apparatus according to the third or fourth aspect, the moving means includes the image reading means and the image reading means based on the image shift amount stored in the other storage means. Are relatively moved in opposite directions.

According to a sixth aspect of the present invention, in the image reading apparatus according to any one of the third to fifth aspects, the other storage means is a nonvolatile storage element.

According to a seventh aspect of the present invention, there is provided the image reading apparatus according to any one of the third to sixth aspects, further comprising a measuring means for measuring the image shift amount.

An image reading apparatus according to claim 8, wherein the image reading means for reading an image, a moving means for relatively moving the image and the image reading means, a temporary stopping means for temporarily stopping the moving means, Storage means for storing an image shift amount during the temporary stop by the temporary stop means, and control means for controlling movement of the moving means based on information of the image shift amount stored by the storage means. Features.

According to a ninth aspect of the present invention, in the image reading apparatus of the eighth aspect, the storage means is a nonvolatile storage element.

According to a tenth aspect of the present invention, there is provided the image reading apparatus according to the eighth or ninth aspect, further comprising a measuring means for measuring the image shift amount.

According to a still further aspect of the present invention, there is provided an image reading method for reading an image by image reading means, a moving step of relatively moving the image and the image reading means, and a temporary stop of the moving step. A stopping step, a storing step of storing the image data read in the image reading step,
A detecting step of detecting an empty remaining amount of the capacity that can be stored in the storing step and a change amount of the image; and a detecting step that the empty remaining amount of the capacity that can be stored in the storing step and the change amount of the image are respectively smaller than predetermined values. A control step of performing control so as to temporarily stop the moving step in the temporary stop step when the detection is performed in the detection step.

According to a twelfth aspect of the present invention, there is provided an image reading method according to the eleventh aspect.
In the image reading method described above, after the moving step is temporarily stopped in the temporary stopping step, when the detecting step detects that the remaining free space of the capacity that can be stored in the storing step is equal to or more than the predetermined value, the moving step is performed. The movement is restarted in the process.

According to a thirteenth aspect of the present invention, there is provided an image reading method according to the eleventh aspect.
13. The image reading method according to claim 12, wherein when the remaining capacity of the storage capacity that can be stored in the storage step is smaller than a predetermined value, the time from when the detection step detects the remaining space to when the movement step is temporarily stopped in the pause step. Characterized by including another storage step of storing the image shift amount.

According to a fourteenth aspect of the present invention, there is provided the image reading method according to the thirteenth aspect.
In the above-described image reading method, the predetermined value is 0.

According to a fifteenth aspect of the present invention, there is provided an image reading method according to the thirteenth aspect.
15. The image reading method according to claim 14, wherein the image and the image reading unit are relatively moved in opposite directions in the moving step based on the image shift amount stored in the another storing step. .

According to a sixteenth aspect of the present invention, there is provided an image reading method according to the thirteenth aspect.
The image reading method according to any one of claims 1 to 15,
A measuring step of measuring the image shift amount.

In an image reading method according to a seventeenth aspect, an image reading step of reading an image by image reading means, a moving step of relatively moving the image and the image reading means, and a temporary stop of the moving step A stopping step, a storing step of storing an image shift amount during the temporary stop in the temporary stopping step, and a control step of controlling movement of the moving step based on information of the image shift amount stored in the storing step. It is characterized by including.

[0023] The image reading method according to the eighteenth aspect is the seventeenth aspect.
The image reading method described above, further comprising a measuring step of measuring the image shift amount.

An image reading device according to a nineteenth aspect is an image reading device for reading an image, a moving device for relatively moving the image and the image reading device, a suspending device for temporarily stopping the moving device, Detecting means for detecting an amount of change in the image read by the image reading means; and when the detecting means detects that the amount of change in the image is smaller than a predetermined value, the suspending means temporarily stops the moving means. Control means for performing control in this manner.

According to a twentieth aspect of the present invention, there is provided an image reading apparatus according to the nineteenth aspect.
The image reading apparatus according to claim 1, further comprising a storage unit that stores the image data read by the image reading unit.

[0027] The image reading apparatus of claim 21 is claim 19.
21. The image reading apparatus according to claim 20, wherein the detection unit detects a change amount of the image based on the image data stored in the storage unit.

[0027] The image reading apparatus according to claim 22 is the claim 19.
The image reading device according to any one of claims 21 to 21,
The storage means is a nonvolatile storage element.

An image reading method according to a twenty-third aspect of the present invention provides an image reading step of reading an image by image reading means, a moving step of relatively moving the image and the image reading means, and a temporary stop of the moving step. A stopping step, a detecting step of detecting a change amount of the image read in the image reading step, and, if the detecting step detects that the change amount of the image is smaller than a predetermined value, the moving step in the temporary stopping step And a control step of controlling so as to temporarily stop.

According to a twenty-fourth aspect of the present invention, there is provided an image reading method according to the twenty-third aspect.
The image reading method described above further includes a storage step of storing the image data read in the image reading step.

According to a twenty-fifth aspect of the present invention, there is provided an image reading method according to the twenty third aspect.
25. The image reading method according to claim 24, wherein the amount of change in the image is detected in the detecting step based on the image data stored in the storing step.

[0031]

Embodiments of the present invention will be described below with reference to the drawings.

(1) First Embodiment FIG. 1 shows a configuration of an image reading apparatus according to a first embodiment of the present invention.

Referring to FIG. 1, an image reading apparatus 101 according to a first embodiment of the present invention includes a paper feed roller 103, a transport roller 104, a paper feed tray 106, a paper discharge tray 107,
A document conveying motor 108 is provided as moving means. Document 102 for reading set on paper feed tray 106
Is fed by a feed roller 103 driven by a document conveying motor 108, and is discharged to a discharge tray 107 through a conveying path by a conveying roller 104.

The image reading apparatus 101 includes an image sensor 105 as image reading means and a buffer memory 109 as storage means.
Reference numeral 05 reads the document 102 transported by the transport rollers 104, and the read image data is temporarily stored in the buffer memory 109.

Further, the buffer memory 109 is connected to the host computer 1 via the interface cable 111.
The image data, which is connected to the buffer memory 109 and is temporarily stored in the buffer memory 109, is transmitted to the host computer 110 via the interface cable 111.

The buffer memory 109 is provided in the CPU 11
2, and a ROM (not shown) storing a program of control contents of the CPU 112. The CPU 112 constitutes control means, temporary stop means, and detection means.

Here, the storage capacity of the buffer memory 109 is smaller than the data capacity of the entire image data of the original 102 for reading, and the speed at which the image data is sent to the host computer 110 via the interface cable 111 is lower than that of the original 102. If the reading speed is lower than the reading speed, the storage capacity of the buffer memory 109 may become full and image data may be lost. So, CP
U 112 detects the remaining amount Rx of the storage capacity of the buffer memory 109, stops the transport of the original 102 before the above-described case occurs, temporarily stops reading the original 102, and temporarily stores the original in the buffer memory 109. After the capacity becomes available, the reading of the document 102 is started again.

FIG. 2 is a program for explaining in detail the image reading process of the image reading apparatus according to the first embodiment.

First, the original document 102 is transported via the transport roller 104 driven by the transport motor 108 and reaches the image sensor 105, and the image sensor 105 reads the image data of the first line (step S20).
1). The read image data is temporarily stored in the buffer memory 109 (step S202). Therefore, the remaining free space Rx in the buffer memory 109 decreases.

In step S203, the CPU 112 determines whether or not the remaining free space Rx in the buffer memory 109 is larger than a certain fixed value R1, for example, the storage capacity of image data for two lines.

The remaining free space Rx in the buffer memory 109
If there is less than a certain constant value R1, the transport motor 108 is stopped and reading of image data is interrupted (step S204). During this time, the image data is sent from the buffer memory 109 to the host computer 110 via the interface cable 111 (step S20).
5). Thereafter, the remaining free space Rx in the buffer memory 109 increases, and the process returns to step S203.

In step S203, the buffer memory 10
If the vacant remaining amount Rx of 9 is equal to or greater than a certain constant value R1, the process proceeds to step S206, and it is determined whether or not image data of all lines has been read.

In step S206, when the image data of all the lines has been read, the present process is terminated. On the other hand, when the image data of all the lines has not been read, the image data of the next line is read (step S206). S20
7) The read image data is stored in the buffer memory 109.
(Step S208).

Next, in step S209, the CPU 112 determines whether or not the remaining free space Rx of the buffer memory 109 is smaller than a predetermined constant value R2 (R2 <R1), for example, the storage capacity of one line of image data. Is determined. If the remaining free space Rx in the buffer memory 109 is smaller than the predetermined fixed value R2, the transport motor 108 is stopped, and the reading of the image data is interrupted (step S210). During this time, the image data is sent from the buffer memory 109 to the host computer 110 via the interface cable 111 (step S2).
11). Thereafter, the remaining free space Rx in the buffer memory 109 increases, and the process returns to step S209.

In step S209, the buffer memory 10
If the remaining free space Rx of the buffer memory 109 is equal to or greater than the predetermined fixed value R2, the process proceeds to step S212.
For example, it is determined whether the storage capacity is smaller than the storage capacity of the image data for two lines. Free space R in buffer memory 109
If x is greater than or equal to any given value R1, step S
Returning to step 206, the image data of the next line is read, and the remaining free space Rx is set to a predetermined constant value R.
If it is smaller than 1, the consecutive 2 stored in the buffer memory 109 by the process described later with reference to FIG.
The CPU 112 detects the amount of change Tx in the image data of the line (step S213), and proceeds to step S214.

FIG. 3 is a diagram schematically showing the read image data. The image data shown in FIG. 3 shows an example in which the image data is read in black and white binary.

The read image data is compared with a predetermined threshold level (threshold), and image data having a level lower than the threshold level is determined to be white and stored as "0" in the buffer memory 109, and is stored in the buffer memory 109. Image data at a level higher than the threshold level is determined to be black, and is stored in the buffer memory 109 as “1”.

Here, when the image data of the x + 1-th row is read, the image data Data (x) of the x-th row is read.
"00011110000 ...", image data Data (x + 1) on the x + 1th row = "0000011110 ..."
Therefore, the amount of change in image data Tx = Data (x +
1) When -Data (x) is calculated, it can be seen that the change amount Tx of the image data is 6, that is, six data are changed.

Returning to FIG. 2, in step S214,
It is determined whether or not the change amount Tx of the image data is equal to or less than a predetermined amount T1. If the change amount Tx of the image data is larger than the predetermined amount T1, the process returns to step S206, and the image data of the next line is read. Motor 108
Is stopped, and reading of image data is interrupted (step S215).

Therefore, in step S214,
For example, when the predetermined amount T1 is set to 3 and the image data of the x + 1-th row in FIG. 3 is read, the image data Data (x) of the x-th row is "00011110000 ...", x +
Image data Data (x + 1) of the first row = “00000”
.., And the change amount Tx of the image data is 3
Therefore, when the image data of the (x + 2) th row in FIG. 3 is read, x + 1
Image data Data (x + 1) on the line = “000000”
11110 ... ", the image data Data (x
+2) = “000001110...” And the change amount Tx of the image data is 3 or less, so that the transport motor 108 is stopped and reading of the image data is interrupted.

The image data is stored in the buffer memory 10.
9 to the host computer 110 via the interface cable 111 (step S216), the free space Rx in the buffer memory 109 increases, and the process returns to step S212.

Incidentally, the above-mentioned arbitrary constant values R1, R2 (R2 <
R1) can be freely set by the user. Further, the arbitrary constant value R1 corresponds to the predetermined value according to claims 1 and 2.

As described above, according to the first embodiment, the remaining amount Rx of the buffer memory 109 is equal to or greater than a certain constant value R2 (NO in step S209) and smaller than the constant value R1 (step S209). If YES in S212, and the variation amount Tx of the image data is equal to or smaller than the predetermined amount T1 (YES in step S214), the transport motor 108 is stopped, and reading of the image data is interrupted (step S215). Image data is stored in the buffer memory 109
To the host computer 110 to increase the free space Rx in the buffer memory 109 (step S21).
6) After the value becomes equal to or more than the fixed value R1 (step S212)
No), the image data of the next line is read (step S206), so that the document can be temporarily stopped before the storage capacity of the buffer memory 109 becomes full, and the free remaining capacity of the storage capacity can be always secured. Further, occurrence of image shift can be prevented.

(2) Second Embodiment The configuration of an image reading apparatus according to a second embodiment of the present invention is substantially the same as the configuration of the image reading apparatus according to the first embodiment of the present invention. There is a difference, however, in that a nonvolatile storage element as another storage unit described later is newly provided. The nonvolatile storage element includes a ROM, an EPROM, and a RAM backed up by a built-in battery.

FIG. 4 is a program for explaining in detail the image reading process of the image reading apparatus according to the second embodiment.

First, the original document 102 is transported via the transport roller 104 driven by the transport motor 108 and reaches the image sensor 105. The image sensor 105 reads the image data of the first line (step S30).
1). The read image data is temporarily stored in the buffer memory 109 (step S302). Therefore, the remaining free space Rx in the buffer memory 109 decreases.

In step S303, the CPU 112 determines whether or not the remaining free space Rx in the buffer memory 109 is larger than a certain fixed value R1, for example, the storage capacity of image data for two lines.

When the remaining free space Rx in the buffer memory 109 is smaller than a certain fixed value R1, the transport motor 108 is stopped and reading of image data is interrupted (step S304). During this time, the image data is sent from the buffer memory 109 to the host computer 110 via the interface cable 111 (step S30).
5). Thereafter, the remaining free space Rx in the buffer memory 109 increases, and the process returns to step S303.

In step S303, the buffer memory 10
If the vacant remaining amount Rx of 9 is equal to or greater than a given constant value R1, the process proceeds to step S306, and it is determined whether or not image data of all lines has been read.

If it is determined in step S306 that all lines of image data have been read, the process ends. If all lines of image data have not been read, the process proceeds to step S307, where the remaining amount of free space in the buffer memory 109 is set. Rx
It is determined whether or not the transport motor 108 is stopped in order to increase the number.

When the transport motor 108 is stopped, the transport motor 108 is rotated in the reverse direction (step S308),
The document is conveyed in reverse. The reverse rotation of the transport motor 108 is performed when the remaining free space Rx of the buffer memory 109 becomes a constant value R1.
This is because an image shift occurs during a period from when the number of charges has decreased to when the conveyance motor 108 is stopped.

The amount of reverse rotation is adjusted at the time of inspection for shipment of the image reading apparatus. This is because the amount of reverse rotation corresponding to the image shift amount can be extracted by comparing the image data of several lines before the conveyance motor 108 stops and the image data at the time of reverse rotation. This is because by storing the amount to be stored in the nonvolatile storage element provided in the image reading apparatus, the transport motor 108 can be reversely rotated in accordance with the amount of image shift accurately.

When the conveyance motor 108 rotates in the reverse direction and the image shift is eliminated, the conveyance motor 108 temporarily stops (step S309). The image data of the next line is read (step S310), and the read image data is stored in the buffer memory 109 (step S31).
1).

In step S307, the transport motor 10
If not stopped, the process proceeds to step S310.

Next, in step S312, the CPU 112 determines whether or not the remaining free space Rx of the buffer memory 109 is smaller than a predetermined constant value R2 (R2 <R1), for example, a storage capacity of one line of image data. Is determined. When the remaining amount Rx of the buffer memory 109 is smaller than the predetermined constant value R2, the transport motor 108 is stopped, and the reading of the image data is interrupted (step S313). During this time, the image data is sent from the buffer memory 109 to the host computer 110 via the interface cable 111 (step S3).
14). Thereafter, the remaining free space Rx in the buffer memory 109 increases, and the process returns to step S312.

In step S312, the buffer memory 10
If the remaining free space Rx of the buffer memory 109 is equal to or larger than the predetermined fixed value R2, the process proceeds to step S315.
For example, it is determined whether the storage capacity is smaller than the storage capacity of the image data for two lines. Free space R in buffer memory 109
If x is greater than or equal to any given value R1, step S
Returning to 306, while reading the image data of the next line, the remaining free space Rx is set to a predetermined constant value R.
If it is smaller than 1, the CPU 112 detects the change amount Tx of the image data of two consecutive lines stored in the buffer memory 109 by the processing described with reference to FIG. 3 described above (step S316), and proceeds to step S317.

In step S317, it is determined whether or not the amount of change Tx of the image data is equal to or less than a predetermined amount T1.
If the change amount Tx of the image data is larger than the predetermined amount T1, the process returns to step S306 to read the image data of the next line, and if the change amount Tx of the image data is equal to or smaller than the predetermined amount T1, the conveyance is performed. The motor 108 is stopped, and the reading of the image data is interrupted (step S318).

Therefore, in step S317,
When the predetermined amount T1 is set to 3 and the image data of the (x + 1) th row in FIG. 3 is read, the image data Data of the xth row is read.
(X) = “00011110000...”, Image data Data (x + 1) of the x + 1st row = “00000000111”
10..., And the change amount Tx of the image data is larger than 3, the process returns to step S306, and the next line is read. On the other hand, when the image data on the x + 2 line in FIG. Eye image data Data (x
+1) = “000001110...”, Image data Data (x + 2) of x + 2 line = “0000000011”
10..., And the change amount Tx of the image data is 3 or less, so that the transport motor 108 is stopped, and the reading of the image data is interrupted.

The image data is stored in the buffer memory 10.
9 to the host computer 110 via the interface cable 111 (step S319), the free space Rx in the buffer memory 109 increases, and the process returns to step S315.

In this image reading apparatus, the amount of reverse rotation of the transport motor 108 corresponding to the amount of image shift is extracted at the time of shipping inspection, and the amount of reverse rotation is stored in the nonvolatile storage element. A sensor or the like as a measuring means for reading the image may be provided, or a function of reading the image shift amount may be added to the image sensor 105, and the transport motor 108 may be reversely rotated based on the read image shift amount.

In step S303, the remaining free space Rx of the buffer memory 109 may be 0, and the user can set it freely.

As described above, according to the second embodiment, by comparing the image data of several lines before the conveyance motor 108 stops and the image data at the time of reverse rotation,
The amount of reverse rotation corresponding to the amount of image shift is extracted, and the amount of reverse rotation is stored in the non-volatile storage element provided in the image reading apparatus. Since the rotation is performed, occurrence of image shift can be prevented.

[0073]

As described above in detail, according to the image reading apparatus of the first aspect, the detecting means detects that the remaining free space in the storage means and the change amount of the image are smaller than the predetermined values. Then, the control means controls the temporary stop means to temporarily stop the moving means, so that the image is temporarily stopped before the storage capacity of the storage means is full, and the free remaining capacity of the storage capacity is always secured. And the occurrence of image shift can be prevented.

According to the image reading apparatus of the second aspect, after the suspending means suspends the moving means, and when the detecting means detects that the remaining storage capacity of the storage means is equal to or more than a predetermined value, the moving means is moved. Since the means resumes the movement, the document can be read while preventing the occurrence of image shift.

According to the third aspect of the present invention, a period from when the detecting means detects that the remaining free space in the storage means is smaller than a predetermined value to when the suspending means temporarily stops the moving means. Since other storage means for storing the image shift amount is provided, the occurrence of the image shift can be more accurately prevented.

According to the image reading apparatus of the fifth aspect, the moving means moves the image and the image reading means relatively in the opposite directions based on the image shift amount stored in the other storage means. The occurrence of image shift can be prevented.

According to the image reading apparatus of the present invention, the image reading means reads the image, the moving means relatively moves the image and the image reading means, the temporary stopping means temporarily stops the moving means, and stores the image. The image shift amount is stored while the means is temporarily stopped by the temporary stop means, and the control means controls the movement of the moving means based on the information of the image shift amount stored by the storage means, thereby preventing occurrence of image shift. can do.

According to the image reading method of the eleventh aspect, when the detection step detects that the remaining free space of the storage capacity that can be stored in the storage step and the change amount of the image are respectively smaller than the predetermined values, the moving step is performed in the pause step. Since the control process is controlled to temporarily stop the image, the image can be temporarily stopped before the capacity that can be stored in the storage process becomes full, so that the remaining capacity of the capacity that can be stored can always be secured, and image shift occurs. Can be prevented.

According to the image reading method of the twelfth aspect, after the movement step is temporarily stopped in the temporary stop step, if the detection step detects that the free remaining capacity of the storage capacity in the storage step is equal to or more than a predetermined value, Since the movement is restarted in the moving step, the document can be read while preventing the occurrence of image shift.

According to the image reading method of the thirteenth aspect, the time from when the detection step detects that the free space remaining in the storage step is smaller than a predetermined value to the time when the moving step is temporarily stopped in the temporary stop step. Since another storage step of storing the image shift amount between the two is included, the occurrence of the image shift can be more accurately prevented.

According to the image reading method of the present invention, the image and the image reading means are relatively moved in opposite directions in the moving step based on the image shift amount of the document stored in the other storing step. The occurrence of image shift can be more accurately prevented.

According to the image reading method of the seventeenth aspect, the image is read by the image reading means in the image reading step, the image and the image reading means are relatively moved in the moving step, and the moving step is temporarily stopped in the pause step. Since the image shift amount during the temporary stop in the suspending step is stored in the storage step, and the movement of the moving step is controlled in the control step based on the information on the image shift amount stored in the storage step, the image shift is performed. Can be prevented from occurring.

According to the nineteenth aspect, the image is read by the image reading means, the image and the image reading means are relatively moved by the moving means, and the moving means is temporarily stopped by the temporary stopping means. Means for detecting a change amount of the image read by the image reading means, and when the detecting means detects that the change amount of the image is smaller than a predetermined value, the control means controls the suspending means to temporarily stop the moving means. So
Image shift can be prevented from occurring.

According to the image reading method of the twenty-third aspect, the image is read by the image reading means in the image reading step, the image and the image reading means are relatively moved in the moving step, and the moving step is temporarily stopped in the pause step. When the detecting step detects the change amount of the image read in the image reading step and detects in the detecting step that the change amount of the image is smaller than a predetermined value, the moving step is temporarily stopped in the pause step. Since control is performed in the control step, occurrence of image shift can be prevented.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an image reading apparatus according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating in detail a process of reading an image by the image reading apparatus according to the first embodiment of the present invention.

FIG. 3 is a diagram schematically illustrating read image data.

FIG. 4 is a flowchart describing in detail an image reading process of an image reading apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Image reading apparatus 102 Document 103 Paper feed roller 104 Transport roller 105 Image sensor 106 Paper feed tray 107 Paper discharge tray 108 Document transport motor 109 Buffer memory 110 Host computer 111 Interface cable 112 CPU

Claims (25)

[Claims] An image reading unit that reads an image, a moving unit that relatively moves the image and the image reading unit, a pause unit that temporarily stops the moving unit, and an image that is read by the image reading unit. Storage means for storing the image data obtained, detecting means for detecting the remaining amount of the storage capacity of the storage means and the change amount of the image, and detecting the remaining amount of the storage capacity of the storage means and the change amount of the image. An image reading apparatus, comprising: control means for controlling the suspending means to suspend the moving means when the detecting means detects that the moving means is smaller than a predetermined value. 2. After the suspending means suspends the moving means, if the detecting means detects that the remaining storage capacity of the storage means is equal to or more than the predetermined value, the moving means moves. 2. The method according to claim 1, wherein
The image reading device according to claim 1. 3. A document which has been moved between the time when said detecting means detects that the remaining free space in the storage capacity of said storing means is smaller than a predetermined value and the time when said suspending means temporarily suspends said moving means. The image reading apparatus according to claim 1, further comprising another storage unit that stores the image shift amount. 4. The image reading apparatus according to claim 3, wherein said predetermined value is zero. 5. The image processing apparatus according to claim 3, wherein the moving unit moves the image and the image reading unit relatively in opposite directions based on the image shift amount stored in the other storage unit. 5. The image reading device according to 4. 6. The image reading apparatus according to claim 3, wherein said another storage means is a nonvolatile storage element. 7. The image reading apparatus according to claim 3, further comprising a measuring unit that measures the image shift amount. 8. An image reading means for reading an image, a moving means for relatively moving the image and the image reading means, a suspending means for temporarily stopping the moving means, and a pause by the suspending means. An image reading apparatus comprising: a storage unit configured to store an image shift amount during the operation; and a control unit configured to control movement of the moving unit based on information of the image shift amount stored by the storage unit. 9. An image reading apparatus according to claim 8, wherein said storage means is a nonvolatile storage element. 10. The image reading apparatus according to claim 8, further comprising a measuring unit that measures the image shift amount. 11. An image reading step of reading an image by an image reading means, a moving step of relatively moving the image and the image reading means, a pause step of temporarily stopping the moving step, and the image reading step. A storage step of storing the image data read in the step, a detection step of detecting a remaining amount of space that can be stored in the storage step and a change amount of the image, and a remaining amount of space that can be stored in the storage step. A control step of performing control so as to suspend the moving step in the suspending step when the detecting step detects that the amount of change in the image is smaller than a predetermined value. 12. After the moving step is temporarily stopped in the suspending step, when the detecting step detects that the free remaining capacity of the storage capacity in the storing step is equal to or more than the predetermined value, the moving step includes The image reading method according to claim 11, wherein the movement is restarted. 13. An image shift amount from a point in time when the detecting step detects that the free space remaining in the storage step is smaller than a predetermined value to a point in time when the moving step is temporarily stopped in the temporarily stopping step. 13. The image reading method according to claim 11, further comprising another storing step of storing the image data. 14. The image reading method according to claim 13, wherein the predetermined value is 0. 15. The image reading unit according to claim 13, wherein the image and the image reading unit are relatively moved in the moving step based on the image shift amount stored in the another storing step. 15. The image reading method according to item 14. 16. The method according to claim 13, further comprising a measuring step of measuring the image shift amount.
The image reading method described in the item. 17. An image reading step of reading an image by an image reading means, a moving step of relatively moving the image and the image reading means, a pause step of temporarily stopping the moving step, and the pause And a control step of controlling the movement of the moving step based on the information of the image shift amount stored in the storing step. Image reading method. 18. The image reading method according to claim 17, further comprising a measuring step of measuring the image shift amount. 19. Image reading means for reading an image, moving means for relatively moving the image and the image reading means, suspending means for temporarily stopping the moving means,
Detecting means for detecting an amount of change in the image read by the image reading means; and when the detecting means detects that the amount of change in the image is smaller than a predetermined value, the suspending means temporarily stops the moving means. An image reading apparatus comprising: a control unit configured to perform control as described above. 20. The image reading apparatus according to claim 19, further comprising a storage unit that stores the image data read by the image reading unit. 21. An image reading apparatus according to claim 19, wherein said detecting means detects a change amount of an image based on the image data stored in said storage means. 22. The image reading apparatus according to claim 19, wherein said storage means is a nonvolatile storage element. 23. An image reading step of reading an image by an image reading means, a moving step of relatively moving the image and the image reading means, a pause step of temporarily stopping the moving step, and the image reading step. A detecting step of detecting a change amount of the image read in the step; and controlling the moving step to be temporarily stopped in the pause step when the detecting step detects that the change amount of the image is smaller than a predetermined value. An image reading method. 24. The image reading method according to claim 23, further comprising a storage step of storing image data read in said image reading step. 25. The image reading method according to claim 23, wherein the amount of change in the image is detected in the detecting step based on the image data stored in the storing step.