JP2001036694A - Picture reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the vibration of a carriage at the reading of a picture by setting acceleration different from that set at the acceleration of a scanning means by a moving means in the case of judging that the deviating quantity of a read pixel is not within an allowable range. SOLUTION: This reader is provided with an exclusive adjusting mode having a function for allowing the picture reader to read on exclusive chart (reference original) provided with the straight line (reference line) C1 of a sub-scanning direction (a carriage-moving direction) to automatically discriminate the deviating quantity of the exclusive chart C with respect to the reference line C1 in the read picture so as to automatically select acceleration of reduced vibration. Namely, since the rocking of the read picture with respect to the reference line C1 (vertical line) of the chart C appears as the deviation of pixels in the read picture, the deviating quantity of the read picture is detected as the number of the pixels. When, deviation larger than a prescribed allowable range is confirmed by this detected deviation quantity, the picture reader judges the change of acceleration, changes acceleration to repeat each reading operation again and when the deviating quantity becomes within the allowable range, it decides acceleration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image reading apparatus such as a scanner used in a digital copying machine.

[0002]

2. Description of the Related Art Conventionally, in an image reading apparatus, an entire document is read by moving a carriage for reading and scanning every one line in the main scanning direction of the document in the sub-scanning direction.
The carriage of the image reading apparatus that moves in the sub-scanning direction reads a document by moving at a constant reading speed after accelerating to a predetermined reading speed according to a reading magnification by a motor.

In the image reading apparatus, the reading magnification is changed by changing the moving speed of the carriage when reading an image by the carriage controlled as described above. In such an image reading apparatus, if the vibration generated when the carriage (CRG) is accelerated remains in the image area (reading area) that moves at a constant speed, the read image of the document fluctuates.

For example, when reading a line (hereinafter referred to as a vertical line) in the sub-scanning direction (carriage advancing direction) on a document, if the carriage vibrates in a reading area, the line is read straight. Instead, it is read as a line swinging in the main scanning direction.

[0005] This is caused by the vibration generated when the carriage is started and the shift of the resonance point of the vibration generated when the carriage changes in speed from acceleration to constant speed. Since the carriage performs a staggered motion due to such vibration of the carriage, the optical system provided on the carriage oscillates left and right, and the reading is performed as if the vertical line was swaying.

In particular, in a digital scanner that converts a read image into an electric signal for each pixel, the vertical lines are also read by being subdivided in a dot array, so that the read image is read with emphasis on shaking.

For this reason, the vibration of the carriage must not be left when moving the image area where the original is actually read.

[0008] As a countermeasure against such vibration of the carriage, it is usually possible to first grasp where the carriage is swaying, and to suppress the swaying portion by using an anti-vibration structure.

However, the measures against vibrations in the structure of the carriage merely shift the resonance point of the carriage, so that there is a concern that vibration at some magnification will increase. In addition, providing the carriage with an anti-vibration structure leads to an increase in the weight of the carriage, leading to an increase in the load on the drive system and an increase in the manufacturing cost of the device such as a special specification of the motor used as the drive system. Become.

Another method is to make the acceleration of the carriage as slow as possible. However, such a change in the acceleration of the carriage does not have a great effect, and there is a great possibility that there is no other way than to change the resonance point. To reduce the acceleration, a long distance is required for accelerating the carriage to a reading speed corresponding to a predetermined reading magnification, which leads to an increase in the size of the image reading apparatus.

[0011] Further, increasing the distance that the carriage moves at a constant speed from the end of acceleration to the reading area where the image is actually read is also one of means for suppressing vibration. In order to increase the distance, the size of the aircraft will be increased.

In the case where the moving speed of the carriage is wide due to various reading magnifications, a method of setting a plurality of kinds of accelerations so as to suppress vibration with respect to the moving speed of the carriage corresponding to all reading magnifications is also available. is there.

However, the structure of the device always varies. For this reason, the vibration level of the carriage may deteriorate depending on the reading magnification among the accelerations set as described above. In this case, the acceleration cannot be changed because the acceleration corresponding to the other reading magnification is optimized, and an aircraft with poor image swing at the above reading magnification occurs.

Further, in order to avoid the above-described carriage vibration at a specific reading magnification, when increasing the type of acceleration corresponding to the reading magnification, a human determines the vibration level of the carriage by visually checking an actual read image. There is a need.
However, when visually judging the shaking of the image, the number of man-hours for manufacturing the apparatus may be increased, or it may not be possible to visually judge the reduced image. Further, if the read image is visually determined and set as described above, it takes a great deal of time and labor, and it cannot be realized as mass production of the apparatus.

As described above, the conventional method has the following problems.

(1) An anti-vibration structure for the carriage causes an increase in driving load and leads to an increase in cost.

(2) Due to the structure of the image reading apparatus, variations occur in each body, so that even if a plurality of types of accelerations are set for the reading magnification, shaking may be worse depending on the body.

(3) When the vibration level is visually determined from the read image, it becomes difficult to determine the vibration level in a reduced image or the like, and the vibration level cannot be measured accurately. In addition, since it takes a lot of time, mass production is not feasible.

[0019]

As described above, in order to suppress the vibration of the carriage at the time of reading an image which appears as shaking in the read image, it takes a lot of time and effort for adjustment, an increase in the size of the apparatus and a reduction in cost. An image reading apparatus that solves the problem of increasing the number of carriages, prevents vibration of the carriage during image reading, suppresses an increase in the number of apparatuses and cost, and provides an image reading apparatus that does not require labor for adjusting the carriage. The purpose is to:

[0020]

An image reading apparatus according to the present invention is provided below a document table on which a document is placed, and includes a plurality of pixels in the main scanning direction with respect to the document on the document table. Scanning means for reading and scanning one line, moving means for accelerating the scanning means in the sub-scanning direction of the original on the original placing table from outside the original reading area, and moving at a constant speed in the original reading area; Reading means for moving the scanning means in the sub-scanning direction by means of the moving means and reading a reference document provided with at least one reference line placed on the document table, on the reference document read by the reading means; Determination means for determining whether or not the shift amount of the read pixel with respect to the reference line is within a predetermined allowable range. When the determination means determines that the shift amount is within the allowable range, the moving means performs the scanning. A first setting means for setting an acceleration when the step is accelerated, and an acceleration different from the acceleration when the moving means accelerates the scanning means when the deviation is judged not to be within the allowable range. It comprises a second setting means for setting the acceleration.

An image reading apparatus according to the present invention is provided below a document table on which a document is placed, and scans one line of a plurality of pixels in the main scanning direction on the document on the document table. Moving means for accelerating the scanning means in the sub-scanning direction of the original on the original placing table from outside of the original reading area, and moving the scanning means at a uniform moving speed in accordance with the reading magnification in the original reading area; Scanning means for moving the scanning means in the sub-scanning direction by the moving means to read a reference document provided with at least one reference line placed on the document table; Determining means for determining whether or not the shift amount of the read pixel with respect to the reference line is within a predetermined allowable range; if the determining means determines that the shift amount is within the allowable range, the moving means performs the scanning; The first setting means for setting the acceleration at the time of accelerating the step with respect to the reading magnification, and the scanning means is accelerated by the moving means when the deviation amount is judged not to be within the allowable range by the judging means. And a second setting means for setting an acceleration different from the acceleration when the reading is performed for the reading magnification.

An image reading apparatus according to the present invention is provided below a document table on which a document is placed, and scans one line consisting of a plurality of pixels in the main scanning direction on the document on the document table. Moving means for accelerating the scanning means in the sub-scanning direction of the original on the original placing table from outside of the original reading area, and moving the scanning means at a uniform moving speed in accordance with the reading magnification in the original reading area; Scanning means for moving the scanning means in the sub-scanning direction by the moving means to read a reference document provided with at least one reference line placed on the document table; Determining means for determining whether or not the shift amount of the read pixel with respect to the reference line is within a predetermined allowable range; if the determining means determines that the shift amount is within the allowable range, the moving means performs the scanning; The first setting means for setting the acceleration when the step is accelerated with respect to the reading magnification, the scanning means is accelerated by the moving means when the deviation amount is judged not to be within the allowable range by the judging means. The second setting means for setting an acceleration different from the acceleration at the time of reading to the reading magnification, and when the acceleration for the reading magnification is set by the first setting means or the second setting means, It comprises an execution unit for executing a setting process of the acceleration with respect to the reading magnification.

An image reading apparatus according to the present invention is provided below an original mounting table on which an original is mounted, and scans an original on the original mounting table for one line composed of a plurality of pixels in the main scanning direction. Moving means for accelerating the scanning means in the sub-scanning direction of the original on the original placing table from outside the original reading area, and moving the scanning means at a uniform moving speed in the original reading area; Reading means for reading a reference document provided with at least one reference line placed on the document table by moving in the sub-scanning direction by means, and a read pixel for the reference line on the reference document read by the reading means Determining means for determining whether or not the amount of deviation is within a predetermined allowable range. When the determining means determines that the amount of deviation is within the allowable range, the moving means accelerates the scanning means. When the first setting means for setting the acceleration and the determination means determine that the deviation amount is not within the allowable range, the moving means changes the acceleration to an acceleration different from the acceleration when the scanning means is accelerated. The reference document is read by the reading unit, and the acceleration is repeatedly changed until the deviation amount is determined to be within the predetermined allowable range by the determining unit, and the acceleration is set when the deviation is determined to be within the allowable range. It consists of setting means.

An image reading apparatus according to the present invention is provided below a document table on which a document is placed, and reads and scans one line composed of a plurality of pixels in the main scanning direction on the document on the document table. Moving means for accelerating the scanning means in the sub-scanning direction of the original on the original placing table from outside the original reading area, and moving the scanning means at a uniform moving speed corresponding to the reading magnification in the original reading area; Scanning means for moving the scanning means in the sub-scanning direction by the moving means to read a reference document provided with at least one reference line placed on the document table; Determining means for determining whether or not the shift amount of the read pixel with respect to the reference line is within a predetermined allowable range; if the determining means determines that the shift amount is within the allowable range, the moving means determines The first setting means for setting the acceleration at the time of accelerating the means with respect to the reading magnification, and the moving means accelerates the scanning means when the deviation amount is judged not to be within the allowable range. The reference document is read by the reading means by changing to an acceleration different from the acceleration when the acceleration is changed, and the acceleration is repeatedly changed until the deviation amount is determined to be within a predetermined allowable range by the determining means. It is constituted by a second setting means for setting the acceleration when the judgment is made with respect to the reading magnification.

An image reading apparatus according to the present invention is provided below a document table on which a document is placed, and scans and scans one line of a plurality of pixels in the main scanning direction on the document on the document table. Moving means for accelerating the scanning means in the sub-scanning direction of the original on the original placing table from outside the original reading area, and moving the scanning means at a uniform moving speed corresponding to the reading magnification in the original reading area; Scanning means for moving the scanning means in the sub-scanning direction by the moving means to read a reference document provided with at least one reference line placed on the document table; Determining means for determining whether or not the shift amount of the read pixel with respect to the reference line is within a predetermined allowable range; if the determining means determines that the shift amount is within the allowable range, the moving means determines The first setting means for setting the acceleration at the time of accelerating the means with respect to the reading magnification, the scanning means is accelerated by the moving means when the deviation is judged not to be within the allowable range by the judging means. The reference document is read by the reading means with an acceleration different from the acceleration at the time of the reading, and the change of the acceleration is repeated until the deviation is determined to be within a predetermined allowable range by the determining means, and the acceleration is determined to be within the allowable range When the acceleration for the reading magnification is set by the second setting unit, the first setting unit, or the second setting unit, which sets the acceleration for the reading magnification, the other reading is performed. It is constituted by executing means for executing a setting process of the acceleration with respect to the magnification.

[0026]

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

FIG. 1 is a sectional view schematically showing an internal configuration of a scanner 10 as an image reading apparatus according to an embodiment of the present invention.

As shown in FIG. 1, a scanner 10 includes an exposure lamp 14 as a light source for illuminating a document D placed on a document table 12, and a scanner 10 for deflecting reflected light from the document D in a predetermined direction. One mirror 16 is attached to a first carriage 18 disposed below the document table 12.

The first carriage 18 is arranged so as to be movable in parallel with the document table 12, and reciprocates below the document table 12 by a drive motor 30 via a moving means such as a toothed belt (not shown). Is done. Drive motor 30
Is constituted by a pulse motor or the like whose speed is controlled by a drive pulse signal or the like.

A second carriage 20 is provided below the document table 12 so as to be movable in parallel with the document table 12. On the second carriage 20, second and third mirrors 22, 24 for sequentially deflecting the reflected light from the document D deflected by the first mirror 16 are attached at right angles to each other. The second carriage 20 is driven by the first carriage 18 with the rotation force from the drive motor 30 transmitted by a toothed belt or the like for driving the first carriage 18, and the second carriage 20 is driven by the first carriage 1.
8 is moved in parallel with the original placing table 12 at a half speed.

An image forming lens 26 for converging the reflected light from the third mirror 24 on the second carriage 20 and a reflected light condensed by the image forming lens 26 are provided below the document table 12. A CCD sensor 28 that receives light and performs photoelectric conversion is provided. The imaging lens 26 is a third mirror 2
The light deflected by 4 is movably disposed in a plane including the optical axis of the light via a driving mechanism (not shown), and moves to form an image of the reflected light at a desired magnification. And
The CCD sensor 28 photoelectrically converts the incident reflected light for each pixel, and outputs an electric signal corresponding to the read original D.

Further, the first carriage 18 starts moving from a predetermined standby position X and reads a document image from a document leading end position Y when reading a document image on a document table. I have.

FIG. 2 is a block diagram schematically showing a driving system of the scanner 10 configured as described above.

The scanner 10 includes a CPU 40 for controlling the entire scanner, a RAM 41 for storing data, a ROM 42 for storing a reading speed and an acceleration corresponding to a reading magnification,
A / D conversion circuit 43 for converting an analog signal from CCD sensor 28 into a digital signal, CCD driver 44 for driving CCD sensor 28, first and second carriages 1
It comprises a motor driver 45 for controlling the rotation of the drive motor 30 for moving the motors 8 and 20, an image correction unit 46 having a shading correction circuit for correcting output signals due to variations in the CCD sensor 28, and the like. The CPU 40 includes the carriage 18,
An operation panel 50 having a selection key for selecting an adjustment mode for adjusting the moving speed of the scanner 20, an instruction key for instructing a scan start, and the like is connected.

Next, vibrations generated in the carriages 18 and 20 will be described.

As shown in FIG. 3, the vibrations generated in the carriages 18 and 20 include the vibration generated at the time of starting and the vibration generated due to the shift of the resonance point when changing from acceleration to constant velocity. This is more likely to occur as the difference from the speed is larger. As shown in FIG. 3, the vibration of the carriages 18 and 20 causes the read image to fluctuate when it enters a region (image region) where the document is actually read.

The moving speed of the carriage 18 at the time of constant speed (at the time of reading a document) and the acceleration at the time of acceleration differ depending on the magnification of reading. For this reason, the resonance point of the carriage 18 may be avoided, and it may not be possible to set an acceleration that can cover all magnifications.

Therefore, several kinds of accelerations are provided for the carriage 18, and these accelerations are selectively used depending on the magnification. That is, in order to avoid different resonance points for each acceleration, several types of accelerations are provided, and accelerations at which no resonance point occurs are selected and set for each magnification.

For example, as shown in FIG. 4, accelerations corresponding to a plurality of magnification ranges are set. An appropriate acceleration is selected within the set acceleration region, and the acceleration is used under the condition that the acceleration vibration is suppressed as much as possible.

Further, since there is a structural variation between the image reading apparatuses, the vibration may increase at the acceleration set as described above. Therefore, the acceleration for each magnification is adjusted.

For example, in a scanner used in a digital copying machine of 65 sheets / minute (CPM), the usable acceleration can be changed within the following range from the precondition of the machine.

Minimum acceleration obtained from the total moving distance of the carriage 18: 8500 mm / S ² Maximum acceleration limited by the torque margin of the drive motor 30: 19500 mm / S ^{2 In} this acceleration range, approximately 2000 mm / S ² FIG. 5 and FIG. 6 show examples of acceleration vibration (speed fluctuation amount) of each magnification with respect to the case where acceleration is set to. However, only the magnification of 60 to 90% is shown. FIGS. 5 and 6 show the maximum amplitude in the image area by measuring the acceleration vibration at each acceleration for each magnification. As shown in FIGS. 5 and 6, the resonance peak at each acceleration is different, so that the vibration peak of the carriage 18 is different.

In the example shown in FIG. 6 (within the range of 60% to 90%), if there are four types of acceleration, it is possible to cover the fluctuation at each magnification (acceleration 13200).
mm / ^{S 2} is not required).

Similarly, with respect to other magnifications, the condition can be easily set by previously checking the fluctuation level with respect to the speed fluctuation amount in the image area.

Therefore, depending on the condition, there is an increase or decrease in the acceleration to be held. Further, since the load applied to the drive system is more advantageous when the acceleration is slower, the priority at the time of selection is selected sequentially from the slower one.

In the case described above, the speed fluctuation amount that does not appear on the image as a signal due to the carriage 18 being swayed is reduced by 50%.
When less mm / s, the acceleration 19500mm / ^{S 2,} is effective in a narrow range of about 71% to 79%. Further, as described above, since there is variation in each aircraft,
To suppress vibrations around 71% and 79%, several additional accelerations must be set.

Therefore, as shown in FIG. 7, a dedicated chart (reference original) C provided with a straight line (reference line) C1 in the sub-scanning direction (moving direction of the carriage) is read, and the dedicated chart C is read. A dedicated adjustment mode having a function of automatically determining the amount of deviation of the read image from the reference line C1 and automatically selecting an acceleration with less vibration is provided.

That is, the reference line (vertical line) C of the chart C
The fluctuation of the read pixel with respect to 1 appears as a pixel shift in the read image as shown in FIG. Therefore, the shift amount in the read image is detected as the number of pixels. When a deviation exceeding a predetermined allowable range is confirmed from the detected deviation amount, the image reading device determines a change in acceleration, changes the acceleration, and reads again. These operations are repeated, and the acceleration is determined when the detected deviation amount falls within the allowable range. By performing the above operation for each magnification, an acceleration suitable for the aircraft is selected.

This makes it possible to automatically determine the acceleration of the carriage in which the amount of displacement falls within the allowable range, thereby simplifying the adjustment of the carriage control.

For example, a description will be given on the assumption that a shift of 50 mm / s in speed fluctuation amount as shown in FIGS. 5 and 6 corresponds to a shift of four pixels with respect to the reference line C1. That is, chart C
A case will be described where the allowable range of the shift amount with respect to the reference line C1 in the read image is 4 pixels, and the shift amount is adjusted to be within 4 pixels.

FIGS. 9A to 9D are diagrams showing examples of the read image of the reference line C1 of the chart C. FIG.

FIG. 9A shows an example of a read image having no shift. In this case, the read pixels with respect to the reference line C1 of the chart C are arranged on a straight line, and there is no shift in the read image.

FIG. 9B shows an example of a read image in which the shift amount is 2 pixels. In this case, the read pixels with respect to the reference line C1 of the chart C are shifted by one pixel to the left and right with respect to the virtual reference line C1 in the read image of the chart C, and are read with a total of two pixels. If the allowable range of the shift amount is four pixels, it is determined that the shift amount is within the allowable range if the shift amount is two pixels shown in FIG. 9B.

FIG. 9C shows an example of a read image having a displacement amount of 4 pixels. In this case, the read pixel with respect to the reference line C1 of the chart C is shifted by two pixels to the left and right with respect to the virtual reference line C1 in the read image of the chart C, and is read with a total of four pixels. If the allowable range of the shift amount is four pixels, it is determined that the shift amount is within the allowable range if the shift amount is the four pixels shown in FIG. 9C.

FIG. 9D shows an example of a read image having a displacement amount of 8 pixels. In this case, the read pixels of the chart C with respect to the reference line C1 are shifted by four pixels to the left and right with respect to the virtual reference line C1 in the read image of the chart C, and are read with a total of eight pixels. When the allowable range of the shift amount is 4 pixels, if the shift amount is 8 pixels shown in FIG.

For example, when the reading magnification is adjusted on the reduction side,
To read the reference line C1 of the chart C at a magnification of 50%
In this case, the acceleration is 8500 mm as the moving speed of the carriage.
/ S ²And the chart C is read. In this reading result
The shift amount of the pixel with respect to the reference line C1 is detected. this
Detected shift amount is 4 pixels or less, which is a reference as an allowable range
In the case of
After setting, move on to adjustment for the next magnification.

The detected shift amount is 4 pixels or more.
In the case, the acceleration is 11500 mm / S ²Set to above and
The same adjustment operation is performed. Repeat the above operation,
Do not set the acceleration until a displacement of 4 pixels or less is obtained.
Push.

It is more advantageous to set the acceleration of the carriage 18 in the image reading apparatus as wide as possible as long as it is within a range that satisfies the specifications of the body as the image reading apparatus.

The vibration of the carriage 18 accompanying the acceleration appears on the entire carriage 18. For this reason, the reference line C1 provided on the chart C can be adjusted by at least one line. However, in order to increase the reliability in detecting the shift amount, as shown in FIG. Reference lines C1,... May be provided.

Next, adjustment of the moving speed of the carriage 18 will be described with reference to a flowchart shown in FIG. Here, a case where there are five settable accelerations will be described as an example.

First, the operator who executes the adjustment process
Chart C provided with reference line C1 on document table 12
Is placed, and the adjustment mode is selected from the operation panel 50,
Indicates the start of adjustment.

Then, the CPU 40 first selects adjustment of the moving speed of the carriage 18 at the minimum magnification n (min) as an object to be adjusted (step 1). CPU40
Selects acceleration 1 as an initial value for the minimum magnification (step 2). The CPU 40 accelerates the carriage 18 at the acceleration 1 and executes a reading operation of the chart C on the document table 12 (step 3).

The CPU 40 obtains pixel data of a read image corresponding to the reference line C1 on the chart C as shown in FIG. 7 from the read image data. The CPU 40 calculates the difference between the maximum value and the minimum value of the read pixel corresponding to the reference line C1 in the main scanning direction, and detects a shift amount in the read image. The CPU 40 determines whether or not the fluctuation of the read image is within the allowable range by determining whether or not the detected shift amount is within a predetermined number of pixels as an allowable range (step 4).

When it is determined that the displacement amount is within the predetermined number of pixels, that is, when it is determined that the fluctuation of the read image is within the allowable range, the CPU 40 sets the acceleration 1 in step 1 described above. The acceleration is determined as the acceleration corresponding to the reading magnification n.

Thus, when the acceleration for the reading magnification n is determined, the CPU 40 determines whether or not the adjusted reading magnification n is the minimum magnification n (min). If it is determined that the reading magnification n is the minimum magnification n (min), the CPU
Numeral 40 designates a reading magnification of n + to adjust the magnification (n + 1) which is 1% larger than the minimum magnification n (min).
Set to 1 (step 6) and return to step 2 above.

When the minimum magnification is not n (min),
The CPU 40 determines whether or not the maximum magnification is n (max). According to this determination, the reading magnification n becomes the maximum magnification n (m
ax) (step 7), the CPU 40 sets the reading magnification to n + 1 (step 8),
Return to If the reading magnification is the maximum magnification n (max) (step 7), the adjustment processing for all the magnifications ends.

Also, in the above step 4, the amount of deviation detected is not within the predetermined number of pixels as an allowable range, ie,
If it is determined that the fluctuation of the read image is not within the allowable range,
The PU 40 changes the acceleration for which an amount that is not within the allowable range is detected. For example, if the selected acceleration is acceleration 1 (step 9), the acceleration 2
Is selected (step 10), the process returns to step 3, and the processing from the chart C reading operation is executed again.

If the selected acceleration is acceleration 2 (step 11), the CPU 40 selects acceleration 3 as the acceleration (step 12), returns to step 3 and returns to step 3 above. Execute the process again.

If the selected acceleration is the acceleration 3 (step 13), the CPU 40 selects the acceleration 4 as the acceleration (step 14), returns to the step 3, and returns to the step 3 from the reading operation of the chart C. Execute the process again.

When the selected acceleration is the acceleration 4 (step 15), the CPU 40 selects the acceleration 5 as the acceleration (step 16), returns to the step 3, and returns to the step 3 from the reading operation of the chart C. Execute the process again.

If the selected acceleration is not the acceleration 4 (step 15), that is, if the selected acceleration is the acceleration 5, the CPU 40 determines that there is no acceleration to be selected, and the CPU 40 cannot adjust the acceleration. Is determined as an error, and the operator is notified of the error by a display unit (not shown) or the like, and the process is stopped.

The above adjustment is performed for each magnification (1.
%), But the vibration corresponding to each magnification of the carriage tends to be as shown in FIGS. 5 and 6, so that the adjustment is performed by thinning out, for example, every 10% in consideration of the adjustment time. You may do it.

As described above, by setting a plurality of accelerations of the carriage and reading a chart provided with a reference line, the swing of the leading end is determined, and an appropriate acceleration is automatically selected from the amount of the swing. I do.

As a result, an image free from shaking can be obtained at any magnification, and the structure can be simplified and the cost can be reduced without relying on visual adjustment or using a special anti-vibration structure. .

[0075]

As described above in detail, according to the present invention, it is possible to prevent the vibration of the carriage during the image reading, to suppress the increase in the number of apparatuses and the cost, and to read the image without the trouble of adjusting the carriage. Equipment can be provided.

[Brief description of the drawings]

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

FIG. 2 is a block diagram illustrating a configuration of a control system of the image reading apparatus.

FIG. 3 is a diagram illustrating a vibration state when the carriage moves.

FIG. 4 is a diagram showing a setting example of a carriage acceleration corresponding to a reading magnification.

FIG. 5 is a diagram showing a speed variation amount (vibration) of a carriage corresponding to various reading magnifications.

FIG. 6 is a diagram illustrating a speed variation amount (vibration) of a carriage corresponding to various reading magnifications.

FIG. 7 is a diagram illustrating a reference line for a chart and a reading direction of a document.

FIG. 8 is a diagram illustrating an example of read pixels of a reference line in a read image of a chart.

FIG. 9 is a diagram illustrating an example of read pixels of a reference line in a read image of a chart.

FIG. 10 is a diagram showing an example of a chart provided with a plurality of reference lines.

FIG. 11 is a flowchart for explaining processing for adjusting the moving speed of the carriage.

[Explanation of symbols]

 12 Document Placement Table 18 First Carriage 20 Second Carriage 28 CCD Sensor 30 Drive Motor 40 CPU 41 RAM 42 ROM 44 CCD Sensor Driver 45 Motor Driver 50 Operation Panel

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/107 F term (Reference) 2H076 AA07 AA37 AA58 AA87 EA24 2H108 AA01 CB01 FB04 FB22 FB41 5B047 AA01 BA02 BB02 BC05 BC14 BC18 CA08 CB06 CB09 CB23 DC07 EB15 5C072 AA01 BA17 EA05 LA02 MB03 RA04 RA18 UA12

Claims (6)

[Claims] A scanning unit provided below a document table on which a document is placed, for reading and scanning one line of a plurality of pixels in the main scanning direction on the document on the document table; Moving means for accelerating the scanning means in the sub-scanning direction of the original on the original placing table from outside the original reading area, and moving the scanning means at a constant moving speed in the original reading area; Reading means for reading a reference document provided with at least one reference line mounted on the document table by moving in the direction, and a shift amount of a read pixel with respect to the reference line on the reference document read by the reading means. A determination means for determining whether or not is within a predetermined allowable range; and an acceleration when the scanning means is accelerated by the moving means when the deviation amount is determined to be within the allowable range. First setting means, and second setting means for setting an acceleration different from the acceleration when the scanning means is accelerated by the moving means, when the deviation amount is judged not to be within the allowable range by the judging means. An image reading apparatus, comprising: A scanning means provided below the document table on which the document is placed, for reading and scanning one line of a plurality of pixels in the main scanning direction on the document on the document table; Moving means for accelerating the scanning means in the sub-scanning direction of the original on the original placing table from outside the original reading area, and moving the scanning means in the original reading area at a constant moving speed according to the reading magnification; and Reading means for reading a reference document provided with at least one reference line placed on the document table by moving in the sub-scanning direction by a moving means; and a reference line on the reference document read by the reading means. Determining means for determining whether or not the shift amount of the read pixel is within a predetermined allowable range; and when the determining means determines that the shift amount is within the allowable range, the moving means accelerates the scanning means. A first setting unit for setting the acceleration of the scanning magnification with respect to the reading magnification; and an acceleration when the scanning unit is accelerated by the moving unit when the deviation amount is determined not to be within the allowable range by the determining unit. An image reading apparatus, comprising: second setting means for setting different accelerations for the reading magnification. A scanning means provided below the document table on which the document is placed, for reading and scanning one line of a plurality of pixels in the main scanning direction on the document on the document table; Moving means for accelerating the scanning means in the sub-scanning direction of the original on the original placing table from outside the original reading area, and moving the scanning means in the original reading area at a constant moving speed according to the reading magnification; and Reading means for reading a reference document provided with at least one reference line placed on the document table by moving in the sub-scanning direction by a moving means; and a reference line on the reference document read by the reading means. Determining means for determining whether or not the shift amount of the read pixel is within a predetermined allowable range; and when the determining means determines that the shift amount is within the allowable range, the moving means accelerates the scanning means. A first setting unit for setting the acceleration of the scanning magnification with respect to the reading magnification; and an acceleration when the scanning unit is accelerated by the moving unit when the deviation amount is determined not to be within the allowable range by the determining unit. A second setting means for setting a different acceleration for the reading magnification; and an acceleration for another reading magnification when the acceleration for the reading magnification is set by the first setting means or the second setting means. And an execution unit for executing the setting process of (1). 4. A scanning means provided below a document placing table on which a document is placed, for reading and scanning one line consisting of a plurality of pixels in the main scanning direction on the document on the document placing table. Moving means for accelerating the scanning means in the sub-scanning direction of the original on the original placing table from outside the original reading area, and moving the scanning means at a constant moving speed in the original reading area; Reading means for reading a reference document provided with at least one reference line mounted on the document table by moving in the direction, and a shift amount of a read pixel with respect to the reference line on the reference document read by the reading means. A determination means for determining whether or not is within a predetermined allowable range; and an acceleration when the scanning means is accelerated by the moving means when the deviation amount is determined to be within the allowable range. A first setting unit, and when the determination unit determines that the deviation amount is not within the allowable range, the moving unit changes the acceleration to an acceleration different from the acceleration when the scanning unit is accelerated, and the reading unit determines A second setting unit that reads the reference document, repeats the change of the acceleration until the deviation is determined to be within a predetermined allowable range by the determination unit, and sets an acceleration when the deviation is determined to be within the allowable range; An image reading apparatus, comprising: 5. A scanning means provided below a document table on which a document is placed, and reads and scans one line consisting of a plurality of pixels in the main scanning direction on the document on the document table. Moving means for accelerating the scanning means in the sub-scanning direction of the original on the original placing table from outside the original reading area, and moving the scanning means at a constant speed corresponding to the reading magnification in the original reading area; Reading means for reading a reference document provided with at least one reference line placed on the document table by moving in the sub-scanning direction by a moving means, and a reference line on the reference document read by the reading means; Determining means for determining whether or not the shift amount of the read pixel is within a predetermined allowable range; and when the determining means determines that the shift amount is within the allowable range, the moving means accelerates the scanning means. First setting means for setting the acceleration at the time of reading with respect to the reading magnification; and acceleration when the scanning means is accelerated by the moving means when the judgment means judges that the deviation amount is not within the allowable range. The reference document is read by the reading means with an acceleration different from the acceleration, and the acceleration is repeatedly changed until the deviation is determined to be within a predetermined allowable range by the determination means, and the deviation is determined to be within the allowable range. And a second setting unit for setting the acceleration of the reading magnification with respect to the reading magnification. 6. A scanning means provided below a document placing table on which a document is placed, for reading and scanning one line of a plurality of pixels in the main scanning direction on the document on the document placing table. Moving means for accelerating the scanning means in the sub-scanning direction of the original on the original placing table from outside the original reading area, and moving the scanning means at a constant speed corresponding to the reading magnification in the original reading area; Reading means for reading a reference document provided with at least one reference line placed on the document table by moving in the sub-scanning direction by a moving means; and a reference line on the reference document read by the reading means. Determining means for determining whether or not the shift amount of the read pixel is within a predetermined allowable range; and when the determining means determines that the shift amount is within the allowable range, the moving means accelerates the scanning means. First setting means for setting the acceleration at the time of reading with respect to the reading magnification; and acceleration when the scanning means is accelerated by the moving means when the judgment means judges that the deviation amount is not within the allowable range. The reference document is read by the reading means with an acceleration different from the acceleration, and the acceleration is repeatedly changed until the deviation is determined to be within a predetermined allowable range by the determination means, and the deviation is determined to be within the allowable range. Setting means for setting the acceleration of the reading magnification to the reading magnification, and when the acceleration for the reading magnification is set by the first setting means or the second setting means, the acceleration for another reading magnification is set. And an execution unit for executing the setting process of (1).