JP2003115979A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize a ratio of the length of a real image to the length of a read image in a moving direction. SOLUTION: The image reader is provided with a laser beam emitting device 10 which emits a laser beam to roll paper (body to be imaged) 2, and a linear CCD camera 11 receives reflected light from the roll paper 2. In this case, a specific stripe pattern called a speckle pattern appears on the light receiving face of an imaging device group of the camera 11. By applying a correlation arithmetic operation between a linear image signal Xn of this time from the camera 11 and a preceding linear image signal Xn-1, the moving amount (d) of the roll paper 2 is obtained. By integrating moving amounts (d), a moving distance D is obtained. Every time the moving distance D reaches a value Dth, the linear image signal S from a camera 5 is captured and multiplied by a factor ts/t (ts is a standard time and t is an integration time until D reaches Dth) to obtain a corrected linear image signal S'.

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 an image on a moving object as a two-dimensional image by using a one-dimensional image pickup means such as a one-dimensional CCD camera.

[0002]

2. Description of the Related Art Conventionally, as this type of image reading apparatus, an image reading apparatus whose image reading section is shown in FIG. 8 and whose image processing section is shown in FIG. 9 has been used. In FIG. 8, reference numeral 1 is a roller, 2 is a roll paper (image pickup object) which is moved by the rotation of the roller 1, 3 is a rotary encoder which generates a two-phase pulse signal according to the rotation amount of the roller 1, and 4 is the roller 1. A stepping motor 5 for rotating is a one-dimensional CCD camera installed vertically to the moving direction of the roll paper 2, and 6-1 and 6-2 are photosensors.

Images G such as photographs are printed on the roll paper 2 at predetermined intervals. The one-dimensional CCD camera 5 has a plurality of image pickup elements, and these image pickup elements are one-dimensional CCDs.
In the installed state of the camera 5, the cameras 5 are arranged in a direction that intersects the moving direction of the roll paper 2 at a substantially right angle (direction parallel to the paper surface of the roll paper 2).

In this image reading apparatus, the following is performed.
The image G printed on the roll paper 2 is read.
While the roller 1 is rotating, that is, while the image G printed on the roll paper 2 is moving, the rotary encoder 3 outputs a two-phase pulse signal. The two-phase pulse signal from the rotary encoder 3 is taken into the control circuit 7 of the image processing unit 100 (FIG. 9). When the control circuit 7 detects by the photo sensor 6-1 that the image G has reached immediately before the imaging position of the one-dimensional CCD camera 5, the control circuit 7 determines the movement amount of the roll paper 2 based on the two-phase pulse signal from the rotary encoder 3. Calculation is performed, and a trigger signal is sent to the one-dimensional CCD camera 5 and the A / D converter 8 each time the movement amount reaches a predetermined movement amount.

The one-dimensional CCD camera 5 outputs the image signal from the image pickup device group as a one-dimensional image signal in synchronization with the trigger signal from the control circuit 7. This one-dimensional image signal is digitized by the A / D converter 8 and sent to the control circuit 7 as a one-dimensional image signal S. The control circuit 7 is 1
The dimensional image signals S are sequentially stored in the image memory 9, and when the image G is no longer detected by the photosensor 6-2, all the one-dimensional image signals S in the image memory 9 are taken out and output to the outside as a two-dimensional image signal. To do.

[0006]

However, in the above-mentioned conventional image reading apparatus, the moving amount of the roll paper 2 is measured by measuring the moving amount of the roller 1 instead of directly measuring the moving amount of the roll paper 2. Since it is obtained indirectly, when the amount of movement of the roll paper 2 and the amount of movement of the roller 1 do not match due to slippage or the like, the length ratio in the moving direction between the actual image and the read image is not stable. was there. For example, when the actual image of the image G is an image as shown in FIG. 10A, the read image is stretched by ds in the moving direction as shown in FIG. 10B due to the slip at the point A. It becomes an image.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an image reading apparatus capable of stabilizing the length ratio of the actual image and the read image in the moving direction. To provide.

[0008]

In order to achieve such an object, a first invention (an invention according to claim 1) is a light irradiating means for irradiating an object to be imaged with light, and this light irradiating means. Light receiving means for receiving the reflected light from the object to be imaged of the light emitted by the means, and movement for measuring the amount of movement of the imaged object by analyzing the reflected light from the object to be imaged received by the light receiving means An amount measuring means is provided to generate a two-dimensional image signal based on the one-dimensional image signal from the one-dimensional imaging means and the movement amount of the object to be imaged from the movement amount measuring means. According to the present invention, the amount of movement of the imaged object is directly measured by analyzing the reflected light from the imaged object, and the directly measured amount of movement of the imaged object and the one-dimensional image signal A two-dimensional image signal is created based on

A second invention (an invention according to claim 2) is a laser light irradiating means for irradiating a laser light toward an object to be imaged.
An image of the speckle pattern formed on the light receiving surface of the light receiving means by the light receiving means for receiving the reflected light of the laser light emitted by the laser light irradiating means from the imaged object, and the diffuse reflection of the laser light on the imaged object. Image signal converting means for converting into a signal, and performing a correlation calculation between the image signal of this time from this image signal converting means and the image signal before this time,
A one-dimensional image signal and movement from the one-dimensional image pickup means are provided with a movement amount measuring means for measuring the amount of deviation of the correlation peak obtained as a point on the coordinate by the correlation calculation from the reference position as the movement amount of the object. A two-dimensional image signal is created based on the amount of movement of the object to be imaged from the amount measuring means. According to the present invention, the speckle pattern (unique spot pattern) formed on the light receiving surface of the light receiving means by the diffuse reflection of the laser light on the imaged object is converted into the image signal, and the image signal of this time and the image signal before this time are converted. Correlation calculation with the image signal is performed, and the amount of deviation from the reference position of the correlation peak obtained as a point on the coordinate by this correlation calculation is measured as the amount of movement of the imaged object and measured directly from the imaged object. A two-dimensional image signal is created based on the moved amount and the one-dimensional image signal.

In the second invention, the image signal before this time is not limited to the previous image signal. That is, the previous image signal may be used as the image signal before this time each time and the correlation calculation with the image signal of this time may be performed, but until the value of the correlation peak becomes smaller than the predetermined value, The correlation calculation may be performed without updating the image signal.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing an outline of an image reading unit in an embodiment of an image reading apparatus according to the present invention. In the figure, the same reference numerals as those in FIG. 8 indicate the same or similar components, and the description thereof will be omitted.

A major difference of this image reading device from the conventional image reading device is that, instead of the rotary encoder 3,
The point is that the laser emitter 10 and the one-dimensional CCD camera 11 are provided. That is, the laser light emitter 10 is provided at a position downstream of the one-dimensional CCD camera 5, and roll paper (image pickup object) is provided.
2 is irradiated with laser light, and the reflected light of the irradiated laser light from the roll paper 2 is received by the one-dimensional CCD camera 11. The one-dimensional CCD camera 11 has a one-dimensional C
Like the CD camera 5, it has a plurality of image pickup elements.

[First Embodiment] FIG. 2 is a block diagram showing an example (first embodiment) of an image processing section in this image reading apparatus. The image processing unit 200 includes an A / D conversion circuit 12, an image processing processor 13, a shift register 14, and a timing signal generator 15 in addition to the configuration of the conventional image processing unit 100.

The timing signal generator 15 outputs a timing signal to the control circuit 7, the one-dimensional CCD camera 11, the A / D converter 12, the image processor 13 and the shift register 14 at a constant cycle t0. The one-dimensional CCD camera 11 outputs the image signal from the image pickup device group as a one-dimensional image signal in synchronization with the timing signal from the timing signal generator 15. The A / D converter 12 receives the timing signal from the timing signal generator 15, digitizes the one-dimensional image signal from the one-dimensional CCD camera 11, and outputs it as a one-dimensional image signal Xn.

The shift register 14 receives the timing signal from the timing signal generator 15, and holds the current one-dimensional image signal Xn output from the A / D converter 12, and holds the previous one-dimensional image signal Xn. To output the one-dimensional image signal Xn-1. The image processor 13 receives the timing signal from the timing signal generator 15,
The current one-dimensional image signal Xn from the A / D converter 12 and the previous one-dimensional image signal Xn from the shift register 14.
-1 is taken in and the movement amount d of the roll paper 2 is calculated.

FIG. 3 shows the calculation processing operation of the movement amount d in the image processor 13. The image processor 13
When receiving the timing signal from the timing signal generator 15, the present one-dimensional image signal Xn from the A / D converter 12 is received.
And the previous one-dimensional image signal Xn-1 from the shift register 14 is fetched. Roll paper 2 is moving now, and image G
Has not been detected by the photo sensor 6-1 yet,
It is assumed that the laser light from the laser light emitter 10 irradiates the blank surface of the roll paper 2.

In this state, the laser light emitted from the laser light emitter 10 (laser light having a sharp directivity, straight line, high brightness, and a single light color) is diffusely reflected on the white surface of the roll paper 2 and is one-dimensional. A unique spot pattern called a speckle pattern is formed on the light receiving surface of the image pickup element group of the CCD camera 11. The image pickup device group of the one-dimensional CCD camera 11 converts this speckle pattern into an image signal, and the A / D converter 12
Send to.

The A / D converter 12 digitizes the image signal (speckle pattern) from the one-dimensional CCD camera 11 and sends it to the image processing processor 13 as the current one-dimensional image signal Xn. Further, the current one-dimensional image signal Xn from the A / D converter 12 is also given to the shift register 14, and the shift register 14 similarly receives the previous one-dimensional image signal Xn-1 inputted in the image processor 13. Send to. In this case, the roll paper 2 has a three-dimensional shape on the surface that differs microscopically on a white surface, so that the speckle pattern of this time and the speckle pattern of the previous time are observed as an image with a positional deviation.

The image processor 13 applies a one-dimensional discrete Fourier transform (one-dimensional DF) to the current one-dimensional image signal Xn.
T) is applied to obtain Fourier image data Fn (step 301). Similarly, the previous one-dimensional image signal X
Fourier image data Fn-1 is obtained by applying a one-dimensional DFT to n-1.
Is obtained (step 302).

The one-dimensional DFT is described in, for example, Document 1 ("Introduction to Computer Image Processing", edited by Japan Industrial Technology Center, published by Soken Shuppan Co., Ltd., P.44-45). The detailed description will be omitted.

Next, the image processor 13 and the Fourier image data Fn obtained in step 301 and step 30
The Fourier image data Fn-1 obtained in 2 are combined to obtain combined Fourier image data Mn (step 303).

Here, the synthetic Fourier image data Mn is
When the Fourier image data Fn is A · e ^j θ and the Fourier image data Fn−1 is B · e ^j φ, Fn−1 is Fn−1.
A · B · e ^{j (} obtained by multiplying the complex conjugate of
θ ^- φ ⁾ . However, A, B, θ, and φ are functions of the spatial frequency (Fourier) space (u, v).

Then, A · B · e ^{j (} θ ⁻ φ ⁾ is A · B · e ^{j (} θ ⁻ φ ⁾ = A · B · cos (θ−φ) + j · A · B · sin (θ− φ) ... (1), A · e ^j θ = α ₁ + jβ ₁ , B · e ^j φ =
Assuming α ₂ + jβ ₂ , A = (α ₁ ² + β ₁ ² ) ^1/2 and B =
(Α ₂ ² + β ₂ ² ) ^1/2 , θ = tan ⁻¹ (β ₁ / α ₁ ), φ =
It becomes tan ⁻¹ (β ₂ / α ₂ ). By calculating the equation (1), the synthetic Fourier image data is obtained.

It should be noted that A ・ B ・ e^{j (}θ^-φ⁾= A ・ B ・ e^j
θ ・ e^-jφ = A ・ e^jθ ・ B ・ e^-jφ = (α₁+ J
β₁) ・ (Α₂-Jβ₂) = (Α₁・ Α₂+ Β₁・
β₂) + J (α ₂・ Β₁-Α₁・ Β₂) As a synthetic frame
Alternatively, the carrier image data may be obtained.

Then, the image processor 13
The composite Fourier image data Mn thus obtained is shaken.
Width suppression processing is performed to obtain synthetic Fourier image data Mn '.
(Step 304). In this embodiment, amplitude suppression
As processing, log processing is performed. That is,
A · B · e, which is an arithmetic expression of the formed Fourier image data^{j (}θ ^-
φ⁾Take the log of the amplitude A ・ B, and log (A ・ B) ・
ej⁽θ^-φ⁾ By setting the amplitude A and B to l
Suppressed to log (A ・ B) (A ・ B> log (A ・ B
B)).

In the synthesized Fourier image data Mn 'subjected to the amplitude suppression processing, the influence of the illuminance difference at the time of sampling the one-dimensional image signal Xn-1 and the one-dimensional image signal Xn becomes small. That is, by performing the amplitude suppression process, the spectrum intensity of each pixel is suppressed, the skipped value is eliminated, and more information becomes effective.

In this embodiment, the log process is performed as the amplitude suppressing process, but the √ process may be performed. Further, not limited to log processing and √ processing,
Any process may be used as long as the amplitude can be suppressed. If all the amplitudes are set to 1, for example, only the phase by the amplitude suppression, that is, there is an advantage that the amount of calculation can be reduced and an amount of data is reduced as compared with the log processing and the √ processing.

Next, the image processor 13 applies a one-dimensional inverse DFT to the synthetic Fourier image data Mn 'which has been subjected to the amplitude suppression processing, and obtains the correlated image data Cn (step 305). Then, the image processor 13 scans the correlation value (amplitude) of each pixel of the correlation image data Cn, sets the point on the coordinate (XY coordinate) having the highest correlation value as the correlation peak, and this X- The distance d from the center of the Y coordinate (reference position) to the correlation peak is calculated (step 30).
6). Then, the calculated distance d, that is, the deviation amount d of the correlation peak from the reference position is calculated as the predetermined time t of the roll paper 2.
It is sent to the control circuit 7 as a movement amount for each 0 (timing signal generation cycle) (step 307).

[Processing in Control Circuit 7] In the control circuit 7, the image G from the one-dimensional CCD camera 5 is detected by the photo sensor 6-1.
When it is detected that the image pickup position has reached immediately before the image pickup position and the timing signal from the timing signal generator 15 is received, the processing operation shown in FIG. 4 is started. In this processing operation, first, D = 0 is set in step 401, and step 40
In 2, t = 0. Note that D in step 401
Indicates the integrated value of the moving distance of the roll paper 2, and step 40
The t at 2 indicates the integrated value of the moving time of the roll paper 2.

Next, the control circuit 7 checks whether or not the movement amount d of the roll paper 2 has been input from the image processor 13 (step 403). When the movement amount d of the roll paper 2 is input (YES in step 403), D = D + d
(Step 404), t = t + t0 (Step 4)
05). Then, the moving distance D obtained in step 404 is compared with a predetermined threshold Dth (step 40
6), steps 403 to 406 until D ≧ Dth
The processing operation of is repeated.

By repeating the processing operations of steps 403 to 406, that is, by integrating the movement amount d, D ≧
When it becomes Dth (YES in step 406), the control circuit 7 outputs a trigger signal to the one-dimensional CCD camera 5 and the A / D converter 8 (step 407). By this trigger signal, the image signal from the image pickup device group of the one-dimensional CCD camera 5 is given to the A / D converter 8, and the image signal digitized by the A / D converter 8 is controlled as the one-dimensional image signal S. It is taken into the circuit 7.

The control circuit 7 multiplies the one-dimensional image signal S from the one-dimensional CCD camera 5 by ts / t as a correction coefficient,
A corrected one-dimensional image signal S'is obtained. Then, the corrected one-dimensional image signal S ′ is stored in the image memory 9 (step 40
9) and returns to step 401. Here, ts is D = D when the roll paper 2 is moved at the normal paper feed speed.
It indicates the time until reaching th and is preset as standard time. That is, if the roll paper 2 moves normally, t = ts at the time of D = Dth.
The value ts / t multiplied by the correction coefficient is 1. On the other hand, if the paper feed speed of the roll paper 2 is delayed due to slip, t> ts, and thus ts / t multiplied by the correction coefficient becomes small.

FIG. 5 shows an example of calculation of the corrected one-dimensional image signal S'obtained every time the moving distance D reaches Dth. In this example, the normal paper feed speed is in the periods 0 to T1, T1 to T2, and T4 to T5, but slips occur during the periods T2 to T3, and the paper feed speed is 1/2 of the normal speed. In the period T3 to T4, the paper feed speed is 0.
(Complete idle rotation).

In the period 0 to T1, the time t at which the moving distance D reaches Dth is t because the paper feeding speed is normal.
= Ts. Therefore, ts / t becomes 1, and the one-dimensional image signal S from the one-dimensional CCD camera 5 becomes the corrected one-dimensional image signal S ′ as it is. Similarly, the periods T1 and T2
In the case of (1) as well, the one-dimensional image signal S from the one-dimensional CCD camera 5 becomes the corrected one-dimensional image signal S ′ as it is because of the normal paper feed speed.

On the other hand, during the periods T2 to T3, slippage occurs and the paper feed speed is 1/2 of the normal speed. In this case, the time t when the moving distance D reaches Dth is
t = 2ts. Therefore, ts / t = ts / 2ts =
It becomes 1/2, and (1/2) · S obtained by multiplying the one-dimensional image signal S from the one-dimensional CCD camera 5 by 1/2 becomes the corrected one-dimensional image signal S ′. In this case, since t = 2ts, the one-dimensional image signal S has a value twice the normal value.
Therefore, by multiplying this one-dimensional image signal S by 1/2, the one-dimensional image signal that would be obtained at a normal paper feed speed is corrected.

In the periods T3 to T4, the paper feed speed is 0 due to complete idle rotation. in this case,
Although the integration proceeds for the time t, the moving distance D remains 0 without being integrated. When the paper feed speed returns to normal at point T4, the integration of the moving distance D starts. In this case, the integration of the moving distance D is advanced in the periods T4 to T5, and the time t when the moving distance D reaches Dth is t = 2ts. Therefore, as in the case of the periods T2 to T3, the one-dimensional C
Multiplying the one-dimensional image signal S from the CD camera 5 by 1/2 (1/2) · S becomes the corrected one-dimensional image signal S ′, which is a one-dimensional image that would be obtained at a normal paper feed speed. The signal will be modified.

In this way, the control circuit 7 calculates the corrected one-dimensional image signal S ′ every time the moving distance D reaches Dth, and stores it in the image memory 9 in order. When the image G is no longer detected by the photo sensor 6-2, all the one-dimensional image signals S in the image memory 9 are taken out and output as a two-dimensional image signal to the outside.

[Second Embodiment] FIG. 6 is a block diagram showing another example (second embodiment) of the image processing section. In this image processing unit 300, the timing signal generator 16 is provided,
The constant cycle t1 output by the timing signal generator 16
The timing signal of 1D CCD camera 5 and A / D
It is given to the converter 8.

In addition, a shift register 17 is provided, and the 1-dimensional CCD camera 5 from the A / D converter 8
The three-dimensional image signal S is held. Further, a switch 18 is provided, and the switch 18 is turned on in response to an instruction from the control circuit 7 so that the one-dimensional image signal S held in the shift register 17 is taken into the control circuit 7.

In the second embodiment, the cycle t of the timing signal output from the timing signal generator 16
1 is equal to the standard time ts described in the first embodiment. The shift register 17 is a one-dimensional CCD.
If the current one-dimensional image signal S from the camera 5 is input,
The previous one-dimensional image signal S held until then is discarded.

[Processing in Control Circuit 7] In the control circuit 7, the image G is captured by the photosensor 6-1 and the one-dimensional CCD camera 5 is used.
When it is detected that the position immediately before the image pickup position of 1 is reached and the timing signal is received from the timing signal generator 15, the operation of the timing signal generator 16 is started, and
The processing operation shown in FIG. 7 is started. In this processing operation, first, in step 701, the moving distance D is set to D = 0.

Next, the control circuit 7 checks whether or not the moving amount d of the roll paper 2 has been input from the image processor 13 (step 702). When the movement amount d of the roll paper 2 is input (YES in step 702), D = D + d
(Step 703), the moving distance D is compared with a predetermined threshold value Dth (step 704), and D ≧ D
The processing operations of steps 702 to 704 are repeated until th is reached.

By repeating the processing operations of steps 702 to 704, that is, by integrating the movement amount d, D ≧
When it becomes Dth (YES in step 704), the control circuit 7 turns on the switch 18. When the switch 18 is turned on, the control circuit 7 starts capturing the one-dimensional image signal S held in the shift register 17 (step 706). When the acquisition of the one-dimensional image signal S is completed (YES in step 706), the switch 1
8 is turned off (step 707), the loaded one-dimensional image signal S is stored in the image memory 9 (step 708),
Return to step 701.

The above operation will be described with reference to the example of FIG. In the period 0 to T1, the time t at which the movement distance D reaches Dth is t = ts because the paper feed speed is normal. In this case, according to the timing signal from the timing signal generator 16, the one-dimensional image signal S at the time point (T1 point) after ts time has passed from the start point (0 point) of the processing operation is sent to the control circuit 7 via the shift register 17. It is captured. Similarly,
Even in the periods T1 and T2, since the paper feed speed is normal, the time point ts has elapsed from the point T1 (point T2)
The one-dimensional image signal S of is taken into the control circuit 7 via the shift register 17.

On the other hand, in the periods T2 to T3, slip occurs and the paper feed speed is 1/2 of the normal speed. In this case, the time t when the moving distance D reaches Dth is
t = 2ts. Here, in the first embodiment, the period T
The one-dimensional image signal S obtained in 2 to T3 is multiplied by 1/2. On the other hand, in the second embodiment, the period T2
1-dimensional image signal rather than the S obtained in to T3, time from T2 points discards a one-dimensional image signal S to the point that has elapsed ts time (T ₂₃ points) has elapsed from T ₂₃ point ts time (T3
The one-dimensional image signal S up to the point) is captured.

In the periods T3 to T4, the paper feed speed is 0 due to complete idle rotation. in this case,
The movement distance D is not accumulated and remains 0. T4
At the point, when the paper feed speed returns to normal, the integration of the moving distance D starts. In this case, the integration of the moving distance D is advanced in the periods T4 to T5, and the time t when the moving distance D reaches Dth is t = 2ts. Here, the first embodiment
Then, 1 is added to the one-dimensional image signal S obtained in the period T3 to T5.
I tried to multiply by / 2. On the other hand, in the second embodiment, not the one-dimensional image signal S obtained in the periods T3 to T5, but 1 from the point T3 to a point (T4 point) after ts time has elapsed.
The one-dimensional image signal S is discarded and the one-dimensional image signal S from the point T4 to the time point (T5 point) after the ts time has elapsed is fetched.

In this way, the control circuit 7 fetches the one-dimensional image signal S each time the moving distance D reaches Dth and sequentially stores it in the image memory 9. When the image G is no longer detected by the photo sensor 6-2, all the one-dimensional image signals S in the image memory 9 are taken out and output as a two-dimensional image signal to the outside.

In the first and second embodiments described above, the image processing processor 13 determines the movement amount d of the roll paper 2 from the current one-dimensional image signal Xn and the previous one-dimensional image signal Xn-1. That is, the previous one-dimensional image signal Xn-1 is used as the one-dimensional image signal before this time each time, and the correlation calculation with the one-dimensional image signal Xn of this time is performed. The correlation calculation may be performed without updating the previous one-dimensional image signal Xn-1 until the value becomes smaller than the predetermined value.

[0049]

As is apparent from the above description, according to the present invention, the amount of movement of the object to be imaged is directly measured by analyzing the reflected light from the object to be imaged. A two-dimensional image signal is created based on the amount of movement of the imaged object and the one-dimensional image signal, and the length ratio in the moving direction between the actual image and the read image can be stabilized. Become. Further, according to the present invention, the speckle pattern (inherent spot pattern) formed on the light receiving surface of the light receiving means by the diffuse reflection of the laser light on the imaged object is converted into the image signal, and the image signal of this time and the current time Also, the correlation calculation with the previous image signal is performed, and the deviation amount from the reference position of the correlation peak obtained as a point on the coordinate by this correlation calculation is measured as the movement amount of the image pickup object, and is directly measured from the image pickup object. The two-dimensional image signal is created based on the movement amount and the one-dimensional image signal measured in the above, and the lengths in the moving direction of the real image and the read image can be obtained without performing any special processing on the object. It becomes possible to stabilize the ratio of.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of an image reading unit in an embodiment of an image reading apparatus according to the present invention.

FIG. 2 is a block diagram showing an example (Embodiment 1) of an image processing unit in the image reading apparatus.

FIG. 3 is a flowchart showing a movement amount calculation processing operation in the image processing processor of the image processing unit.

FIG. 4 is a flowchart showing a processing operation in a control circuit of the image processing unit.

FIG. 5 is a diagram illustrating an example of calculating a corrected one-dimensional image signal S ′ that is obtained every time the moving distance D reaches Dth.

FIG. 6 is a block diagram showing another example (Embodiment 2) of the image processing unit.

FIG. 7 is a flowchart showing a processing operation in a control circuit of the image processing unit.

FIG. 8 is a diagram showing an outline of an image reading unit of a conventional image reading apparatus.

FIG. 9 is a block diagram showing an outline of an image processing unit of a conventional image reading apparatus.

FIG. 10 is a diagram illustrating an actual image of an image G printed on roll paper and a read image stretched by slipping at a point A.

[Explanation of reference numerals] 1 ... roller, 2 ... roll paper, 4 ... stepping motor,
5 ... 1-dimensional CCD camera, 6-1, 6-2 ... Photo sensor, 7 ... Control circuit, 8 ... A / D converter, 9 ... Image memory, 10 ... Laser emitter, 11 ... 1-dimensional CCD camera,
12 ... A / D converter, 13 ... Image processor, 1
4, 17 ... Shift register, 15, 16 ... Timing signal generator, 18 ... Switch, 200, 300 ... Image processing unit.

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Claims (3)

[Claims] 1. A moving means for moving an image pickup object, and a plurality of image pickup elements arranged in a direction intersecting with a moving direction of the image pickup object. Image signals from these image pickup elements are output as a one-dimensional image signal. A one-dimensional image pickup means, a light irradiating means for irradiating the object to be imaged with light, a light receiving means for receiving the reflected light from the object to be imaged of the light emitted by the light irradiating means, and the light receiving means. Moving amount measuring means for measuring a moving amount of the imaged object by analyzing reflected light from the imaged object received by the means, and a one-dimensional image signal from the one-dimensional imaging means and the moving amount measurement 2 based on the amount of movement of the imaged body from the means
An image reading apparatus comprising: a two-dimensional image signal creating means for creating a three-dimensional image signal. 2. A moving means for moving an image pickup object, and a plurality of image pickup elements arranged in a direction intersecting with a moving direction of the image pickup object, and image signals from these image pickup elements are output as a one-dimensional image signal. One-dimensional imaging means, laser light irradiation means for irradiating the object to be imaged with laser light, and light receiving means for receiving the reflected light from the object to be imaged of the laser light emitted by the laser light irradiation means. An image signal converting means for converting the speckle pattern formed on the light receiving surface of the light receiving means into an image signal by diffuse reflection of the laser light on the imaged object, and the image signal of this time from the image signal converting means. Then, the correlation calculation with the image signal before this time is performed, and the shift amount from the reference position of the correlation peak obtained as a point on the coordinate by this correlation calculation is used as the movement amount of the image pickup object. A shift amount measuring means for constant, 2 based on the movement amount of the object to be imaged from one-dimensional image signal and the shift amount measuring means from the one-dimensional imaging unit
An image reading apparatus comprising: a two-dimensional image signal creating means for creating a three-dimensional image signal. 3. The image reading apparatus according to claim 2, wherein the movement amount measuring unit performs a correlation calculation between the current image signal and the previous image signal from the image signal converting unit, and the correlation peak. An image reading apparatus that performs a correlation calculation without updating a previous image signal until the value of is smaller than a predetermined value.