JP2001127965A - Image scanner and start-stop control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the smooth joining of images to improve the image quality at present, where the higher resolution and deeper reading density are required and also the start-stop frequency increases due to the increase in the quantity of data to be read, in contrast to the conventional image scanner where the image read start timing is not completely synchronized with the exciting timing of a motor that moves the reading position to cause a timing error equivalent to a single line of reading resolution in a start mode after a stop mode, and accordingly the data are read with redundancy/omission that is smaller than the quantity equivalent to a single line of resolution, which defective reading result, however, could be disregarded for the resolution and reading density of the conventional image scanner device. SOLUTION: A means is prepared to secure the same time difference between the image reading start timing and the exciting timing of a stepping motor that moves the reading position before the image reading is discontinued and when the image reading is restarted. Thus, the start-stop image error can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image scanner apparatus and a start / stop control method, and more particularly, to a timing of starting image reading and a reading position before image reading is interrupted and when image reading is restarted. Means are provided for making the time difference from the excitation timing of the stepping motor to be moved the same, so that the displacement at the seam of the images is eliminated.

[0002]

2. Description of the Related Art It is desired that an image scanner be equipped with a memory (data storage medium) having a maximum readable image data size. However, since the price of the memory is expensive, it is difficult to realize it as a product. Therefore, usually, the memory mounted in the start / stop control is reduced.

The start / stop control will be described. When the image reading speed at which an image is read is faster than the image discharging speed at which an image is discharged to a host computer or the like, a portion that cannot be discharged is stored in a memory in the apparatus. When the memory is full, the device stops reading the temporary image (stop). Thereafter, when the memory becomes empty due to the ejection of the image, the apparatus resumes reading the image from the interrupted position (start).

[0004] A joint portion between an image until the interruption (stop) and the image after the resumption (start) is referred to as a "joint of images" or simply "joint".

FIG. 10 is a block diagram showing the configuration of a conventional image scanner. In the figure, reference numeral 100 denotes an image scanner connected to a host computer. The image scanner 100 includes a CCD 1001 for converting an image into an electric signal, a memory 1003 for temporarily storing image data, and an image from the CCD 1001. An image control circuit 1002 for transferring data to the memory 1003 and sending an interrupt signal (Hsync signal) to the CPU 1005 when reading image data for each line; and an interface circuit 1006 for transferring the image data in the memory 1003 to the host computer as needed. A stepping motor 1007 for moving the carrier, a motor driver 1008 for driving the stepping motor 1007 by instructing the excitation phase,
A motor timer 100 that generates an excitation phase switching signal for the motor driver 1008 and sends an interrupt signal (motor timer signal) to the CPU 1005 at the excitation phase switching timing.
4, the stepping motor 1007 is driven via the motor driver 1008 according to the interrupt signal (motor timer signal) of the motor timer 1004, and the image reading speed is faster than the image discharging speed, and the image data in the memory becomes full. When the CPU 1005 stops the stepping motor 1007 by stopping the motor timer 1004, and then restarts the motor timer 1004 when the memory 1003 becomes empty by discharging the image data. Is provided.

Referring to FIGS. 11 to 13, a detailed operation of the start / stop control of the conventional image scanner will be described. FIG. 11 is a processing flowchart of a conventional motor control unit, FIG. 12 is a diagram showing an example of a relationship between a conventional Hsync signal and a timer signal, and FIG. 13 is a diagram of a joint of images when a conventional start / stop occurs.

Hereinafter, the operation will be described in accordance with the flow of FIG. The processing of the monitor control unit is performed when a document is set on the image scanner and a reading instruction is issued from the host computer to the image scanner.
It is executed by the CPU.

Step S1101: The motor timer and the image control circuit are activated to start image reading. When an interrupt signal (timer signal) is generated from the motor timer and this signal is received, an interrupt process not described sends an instruction to switch the excitation phase to the motor driver for each interrupt, and drives the stepping motor. The image data read by the CCD is stored in a memory via an image control circuit,
Every time one line of image data is read, an interrupt signal (Hsync signal) is generated from the image control circuit.

Step S1102: It is determined whether reading of the set document has been completed. If the reading has been completed, the process ends. If the reading has not been completed, the process proceeds to step S1103.

Step S1103: Determine whether the memory is full of image data. If full, step S1
Go to step 104, if not full, step S110
Return to 2.

Step S1104: The image control circuit is controlled to stop reading image data.

Step S1105: The motor timer is stopped. As a result, an interrupt signal (timer signal) from the motor timer is not generated, and an interrupt process for transmitting an excitation phase switching instruction to the motor driver is not executed, so that the stepping motor stops.

Step S1106: It is determined whether the memory is empty. If the memory is free, the process proceeds to step S1107; if the memory is not free, step S1106 is performed.
Return to

Step S1107: The motor timer is started. As a result, an interrupt signal (timer signal) from the motor timer is generated, and an interrupt process not described sends an instruction to switch the excitation phase to the motor driver for each interrupt, and the stepping motor is driven again. .

Step S1108: Reading of the image is restarted. Then, the process returns to step S1102.

FIG. 12A is a diagram showing an example of the relationship between the Hsync signal and the timer signal when a start / stop does not occur. When the read image is small (the amount of image data is small), steps S1101 to S1103 are performed.
The image reading process is performed during the period. FIG. 12 (b)
FIG. 8 is a diagram showing an example of the relationship between the Hsync signal and the timer signal when a start / stop occurs. Will be

In this example, since the memory becomes full at T1, reading of the image is stopped, and an interrupt signal (Hsync signal) is received from the image control circuit after T1, and T2 is read.
Stops the motor timer. Thereafter, no interrupt processing is performed, and no excitation phase switching instruction is sent to the motor driver, so that the stepping motor stops. Then, when it is confirmed that the memory is empty at T3, T
In step 4, the motor timer is started and a timer signal is generated. As a result, an interrupt process is executed, an excitation phase switching instruction is sent to the motor driver, and the stepping motor is restarted. Then, the image reading is restarted.

At this time, when the Hsync signal stops, the next timer signal is generated at time t after the Hsync signal. At the start of the Hsync signal, the timer signal starts from T6 and It starts before T5 which is the same timing as the time point.

In this case, the read image is partially missing, for example, shifted in the missing direction shown in FIG.
When the timer signal starts after T5 which is the same timing as the stop point, the read images partially overlap, and are shifted in the overlapping direction shown in FIG. 13A, for example.

[0020]

As described above, in the prior art, the Hsync signal and the timer signal are not completely synchronized, and the start after the stop is caused by the Hsync after the stepping motor reaches the reading restart position. This is done by a signal. Since the Hsync signal is generated at a constant interval for discharging CCD data, the difference between the timer signal and the Hsync signal at the reading restart position is Hs
This is equivalent to one pulse of the sync signal, that is, one line of the reading resolution.

Therefore, when a start / stop occurs, one of the image results is output, whether one or less lines of the reading resolution are read redundantly or read with a missing portion.

Although such image results could be neglected in the resolution and the reading density of the conventional apparatus, at present, in the image scanner apparatus, the higher resolution and the reading density are increasingly used. As the read data increases, the frequency of occurrence of start / stop increases, and smoothness of image joints, which is one of image quality, is required.

Further, when the carrier on which the CCD is mounted moves to the reading restart position, there is a problem that a mechanical shift occurs in the positional accuracy, and this shift is increased by the current high density and high resolution of the CCD. Therefore, it is desired to be corrected.

[0024]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described problems, and is directed to an image scanner apparatus that reads an image by start-stop control.
Means are provided for equalizing the time difference between the timing of starting image reading and the timing of excitation of the stepping motor for moving the reading position between before the image reading is interrupted and when the image reading is restarted. Is to eliminate.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) In an image scanner apparatus for reading an image by start / stop control, the timing of starting the image reading and the reading position are moved before the image reading is interrupted and when the image reading is restarted. By providing the motor control means for making the time difference from the excitation timing of the stepping motor the same, it is possible to eliminate the image shift at the joint at the start / stop.

(2) In the image scanner described in (1), a CCD for converting an image into an electric signal, a memory for temporarily storing image data, and image data from the CCD are transferred to the memory, and one line An image control circuit that sends an interrupt signal to the CPU when reading image data for each, a stepping motor that moves the carrier, a motor driver that drives the stepping motor by instructing the excitation phase,
A motor timer that generates an excitation phase switching signal of the motor driver and sends an interrupt signal to the CPU at the excitation phase switching timing; a stepping motor is driven via the motor driver according to the motor timer interrupt signal; Is faster than the image discharge speed, and when the image data in the memory is full, without stopping the motor timer,
CPU that stops the stepping motor by ignoring the interrupt signal from the motor timer, and then restarts the stepping motor by enabling the interrupt signal from the motor timer when the memory is emptied by discharging image data. By having the above, the time difference between the timing of starting image reading and the timing of excitation for driving the motor can be made the same between before the image reading is interrupted and when the image reading is resumed, and when the start and stop are performed. It is possible to eliminate the image shift at the joint.

(3) In an image scanner device which performs image reading at a reading speed that requires slewing (running) and start / stop control, when image reading is interrupted, the motor is slewed down and backed to perform image reading. When the image reading is resumed, the motor control means for setting the total time of the back-and-force control for performing the motor through-up to an integral multiple of the image data reading time for each line is provided, so that the time before the image reading is interrupted and the image When reading is restarted, the time difference between the timing of starting image reading and the timing of excitation for driving the motor can be made the same, and the image shift at the joint at the time of start / stop can be eliminated.

(4) In the image scanner described in (3), a CCD for converting an image into an electric signal, a memory for temporarily storing image data, and image data from the CCD are transferred to the memory, and one line is output. An image control circuit that sends an interrupt signal to the CPU when reading image data for each, a stepping motor that moves the carrier, a motor driver that drives the stepping motor by instructing the excitation phase,
A motor timer that generates an excitation phase switching signal of the motor driver and sends an interrupt signal to the CPU at the excitation phase switching timing; a motor timer setting during normal driving of the stepping motor, and through-up and through-down; According to the interrupt signal of the motor timer, the stepping motor is driven via the motor driver, and when the image reading speed is faster than the image discharging speed and the image data in the memory is full, the motor is slewed down and back. Then, when the motor timer is stopped, when the memory is emptied by discharging the image data, the time required for the through-down and back, the time required for the through-up to be performed from now on, and the stop time for stopping the motor timer are determined. So that the sum is an integral multiple of the image data reading time for each line By providing a CPU that performs a slew-up after adjusting the top time, the time difference between the timing of starting image reading and the timing of excitation for driving the motor can be determined before and after image reading is interrupted. It is possible to make the same, and it is possible to eliminate the image shift at the joint at the start and stop.

(5) In the image scanner described in (2) or (4), when reading is resumed, a correction value is read from a correction value storage section for storing a correction value for a mechanical deviation, and the reading start position is determined. By providing a CPU that shifts by a minute amount, a mechanical shift at the time of resuming reading can be corrected, and an image shift at a joint at the time of start / stop can be eliminated.

(6) CCD for converting an image into an electric signal
A memory for temporarily storing image data, an image control circuit for transferring image data from the CCD to the memory, and sending an interrupt signal to the CPU when reading image data for each line, and a stepping device for moving the carrier. A motor, a motor driver for instructing the excitation phase to drive the stepping motor, an excitation phase switching signal for the motor driver, a motor timer for sending an interrupt signal to the CPU at the excitation phase switching timing, and a motor timer interrupt In a start / stop control method in an image scanner apparatus provided with a CPU that drives a stepping motor via a motor driver according to a signal, an image reading speed is faster than an image discharging speed, and image data in a memory is full. When the motor timer does not stop, the interrupt signal from the motor timer Stop stepping motor by ignoring, then, when the memory is empty by the discharge of the image data, by enabling an interrupt signal from the motor timer and restart the stepper motor. Thereby, the time difference between the timing of starting the image reading and the timing of the excitation for driving the motor can be made the same between before the image reading is interrupted and when the image reading is restarted,
It is possible to eliminate the image shift at the joint at the time of start / stop.

(7) CCD for converting an image into an electric signal
A memory for temporarily storing image data, an image control circuit for transferring image data from the CCD to the memory, and sending an interrupt signal to the CPU when reading image data for each line, and a stepping device for moving the carrier. A motor, a motor driver that drives the stepping motor by instructing the excitation phase, a motor timer that generates an excitation phase switching signal of the motor driver, and sends an interrupt signal to the CPU at the excitation phase switching timing, C, which drives the stepping motor via the motor driver in accordance with the setting of the motor timer at the time of driving, through-up and through-down, and the interrupt signal of the motor timer
In the start / stop control method in the image scanner device provided with the PU, the image reading speed is faster than the image discharging speed, and when the image data in the memory is full, after the motor is through-down and back,
When the motor timer is stopped and the memory is emptied by discharging the image data, the sum of the time required for through-down and back-up, the time required for the through-up to be performed from now on, and the stop time for stopping the motor timer are calculated. After adjusting the stop time so as to be an integral multiple of the image data reading time for each line, the through-up is performed.
As a result, the time difference between the start of image reading and the timing of excitation for driving the motor can be made the same between before the image reading is interrupted and when the image reading is restarted. Misalignment can be eliminated.

(8) In the start / stop control method described in (6) or (7), when reading is restarted, a correction value is read from a correction value storage section for storing a correction value for a mechanical deviation to correct the reading start position. Shift by the value. This allows
It is possible to correct a mechanical shift at the time of resuming reading, and to eliminate an image shift at a joint at the start and stop.

[0033]

FIG. 1 is a block diagram showing an example of the configuration of an image scanner according to the present invention. In FIG. 1, reference numeral 1 denotes an image scanner connected to a host computer. The image scanner 1 is a CCD for converting an image into an electric signal.
101, a memory 103 for temporarily storing image data
When the image data from the CCD 101 is transferred to the memory 103 and the image data for each line is read, the CPU 10
5, an image control circuit 102 for transmitting an interrupt signal (Hsync signal), an interface circuit 106 for transferring image data in a memory 103 to a host computer as needed, a stepping motor 107 for moving a carrier, and a stepping motor for instructing an excitation phase. A motor driver 108 for driving the motor driver 107 and an excitation phase switching signal for the motor driver 108 are generated.
A motor timer 104 for sending an interrupt signal (motor timer signal) to the motor 105; a stepping motor 107 driven via a motor driver 108 in accordance with the interrupt signal of the motor timer 104; When the image data is full, the stepping motor 1007 is stopped by ignoring the interrupt signal from the motor timer without stopping the motor timer, and thereafter, when the memory 103 becomes empty by discharging the image data. CPU that restarts the stepping motor by enabling an interrupt signal from the motor timer 104
105 and a ROM 109 in which control values at the time of start / stop are stored.

The control values stored in the ROM 109 are as follows:
A mechanical shift correction value for correcting a mechanical shift when reading is resumed after image reading is interrupted, a step-down motor through-down and back when image reading is interrupted, and a step-up motor through-up when image reading is restarted. Back and force timer value which is a timer value of the back and force control for performing the following.

The detailed operation of the start / stop control of the image scanner of the present invention will be described with reference to FIGS. FIG. 2 is a processing flowchart (1) of an embodiment of the motor control unit of the present invention, FIG. 3 is a diagram showing an example of the relationship between the Hsync signal and the timer signal (1), and FIG. FIG.

The operation will be described below with reference to the flow chart of FIG. The processing of the monitor control unit is performed when a document is set on the image scanner and a reading instruction is issued from the host computer to the image scanner.
Performed by the PU.

Step S201: The motor timer and the image control circuit are activated to start image reading. When an interrupt signal (timer signal) is generated from the motor timer and this signal is received, an interrupt process not described sends an instruction to switch the excitation phase to the motor driver for each interrupt, and drives the stepping motor. The image data read by the CCD is stored in a memory via an image control circuit, and an interrupt signal (Hsync signal) is generated from the image control circuit every time one line of image data is read.

Step S202: It is determined whether reading of the set document has been completed. If the reading has been completed, the process ends. If the reading has not been completed, the process proceeds to step S203.

Step S203: Determine whether the memory is full of image data. If full, step S20
The process proceeds to step S4, and if not full, returns to step S202.

Step S204: The image control circuit is controlled to stop reading image data.

Step S205: An interrupt signal (timer signal) generated from the motor timer is ignored.
As a result, the stepping motor is stopped without sending an instruction to switch the excitation phase to the motor driver in the interrupt processing.

Step S206: It is determined whether the memory is empty. If the memory is empty, the process proceeds to step S207, and if the memory is not empty, the process returns to step S206.

Step S207: An interrupt signal (timer signal) generated from the motor timer is received. As a result, an interrupt process not described sends an instruction to switch the excitation phase to the motor driver for each interrupt, and the stepping motor is driven again.

Step S208: Image reading is restarted. Then, the process returns to step S202.

FIG. 3A is a diagram showing an example of the relationship between the Hsync signal and the timer signal when a start / stop does not occur. When the read image is small (the amount of image data is small).
For example, the image reading process is performed between step S201 and step S203. FIG. 3B is a diagram showing an example of the relationship between the Hsync signal and the timer signal when a start / stop occurs. When the read image is large (the image data is large), steps S204 to S2 are performed.
Image reading processing accompanied by start / stop control 08 is performed.

In this example, since the memory is full at T1, the reading of the image is stopped, and an interrupt signal (Hsync signal) is received from the image control circuit after T1, and T2 is read.
Ignoring the interrupt signal (timer signal) of the motor timer. Accordingly, thereafter, no interrupt processing is performed, and no excitation switching instruction is sent to the motor driver, so that the stepping motor stops. Then, when it is confirmed at T3 that the memory is empty, the interrupt signal (timer signal) of the motor timer is made valid at T4.
As a result, an interrupt process is executed, an excitation switching instruction is sent to the motor driver, and the stepping motor is restarted. Then, the image reading is restarted.

By performing such processing, the time difference t (arrow A) between the Hsync signal and the timer signal at the time of stop and the time difference t (arrow B) between the Hsync signal and the timer signal at the time of start can be made equal.
That is, the time difference between the timing of starting the image reading and the timing of exciting the stepping motor for moving the reading position can be made the same before the image reading is interrupted and when the image reading is restarted.

Therefore, even when a start / stop occurs, there is no missing or duplicated image at the joint between the images.
The image shown in FIG. 4 can be obtained.

With reference to FIGS. 5 to 7, the operation of the start / stop control of the image scanner apparatus in which a positional deviation causes a mechanical shift when the carrier moves to the reading restart position will be described. FIG. 5 is a processing flowchart (2) of an embodiment of the motor control unit of the present invention, and FIG.
FIG. 2 is a diagram showing an example of the relationship between the c signal and the timer signal, and FIG.
It is.

Hereinafter, the operation will be described in accordance with the flow of FIG. The processing of the monitor control unit is performed when a document is set on the image scanner and a reading instruction is issued from the host computer to the image scanner.
Performed by the PU.

Step S501: A mechanical shift correction value for correcting a mechanical shift when reading is resumed after image reading is interrupted is read from the nonvolatile memory.

Step S502: The motor timer and the image control circuit are activated to start image reading. When an interrupt signal (timer signal) is generated from the motor timer and this signal is received, an interrupt process not described sends an instruction to switch the excitation phase to the motor driver for each interrupt, and drives the stepping motor. The image data read by the CCD is stored in a memory via an image control circuit, and an interrupt signal (Hsync signal) is generated from the image control circuit every time one line of image data is read.

Step S503: It is determined whether reading of the set document has been completed. If the reading has been completed, the process ends. If the reading has not been completed, the process proceeds to step S504.

Step S504: Determine whether the memory is full of image data. If full, step S50
Proceed to step S5, and if not full, return to step S503.

Step S505: The image control circuit is controlled to stop reading image data.

Step S506: An interrupt signal (timer signal) generated from the motor timer is ignored.
As a result, the stepping motor is stopped without sending an excitation switching instruction to the motor driver in the interrupt processing.

Step S507: It is determined whether the memory is empty. If the memory is empty, the process proceeds to step S508, and if the memory is not empty, the process returns to step S507.

Step S508: An interrupt signal (timer signal) generated from the motor timer is received. As a result, an interrupt process not described sends an instruction to switch the excitation phase to the motor driver for each interrupt, and the stepping motor is driven again.

Step S509: Waits for the stepping motor to move by the correction value read in step S501. As a result, it is possible to correct the mechanical displacement and correct the reading start position.

Step S510: Reading of the image is restarted. Then, the process returns to step S503.

FIG. 6A is a diagram showing an example of the relationship between the Hsync signal and the timer signal when no start / stop occurs. When the read image is small (the amount of image data is small).
For example, the image reading process is performed between step S502 and step S504. FIG. 6B is a diagram illustrating an example of the relationship between the Hsync signal and the timer signal when a start / stop occurs. When the read image is large (the image data is large), steps S505 to S5 are performed.
An image reading process with start / stop control of 10 is performed.

In this example, since the memory is full at T1, reading of the image is stopped, and an interrupt signal (Hsync signal) is received from the image control circuit after T1, and T2 is read.
Ignoring the interrupt signal (timer signal) of the motor timer. Accordingly, thereafter, no interrupt processing is performed, and no excitation switching instruction is sent to the motor driver, so that the stepping motor stops. Then, when it is confirmed at T3 that the memory is empty, the interrupt signal (timer signal) of the motor timer is made valid at T4.
As a result, an interrupt process is executed, an excitation switching instruction is sent to the motor driver, and the stepping motor is restarted. Then, the image reading is restarted after the stepping motor is moved by the correction value (in this example, two pulses of the motor timer signal).

By performing such processing, the time difference t (arrow A) between the Hsync signal and the timer signal at the time of stop and the time difference t (arrow B) between the Hsync signal and the timer signal at the time of start can be made the same.
That is, the time difference between the timing of starting image reading and the timing of exciting the stepping motor for moving the reading position can be made the same between before the image reading is interrupted and when the image reading is restarted, and when the image reading is started. It is possible to correct a mechanical shift at the time.

Therefore, at the time of start / stop, FIG.
An apparatus having a mechanical displacement of two pulses in the missing direction as shown in (a) can be corrected by setting the mechanical displacement correction value to “2”.
It is possible to obtain the image shown in FIG.

Referring to FIG. 8 to FIG. 9, the operation of the start / stop control of the image scanner apparatus for performing the back and force control will be described. FIG. 8 is a processing flowchart (3) of the embodiment of the motor control unit according to the present invention, and FIG. 9 is a diagram (3) showing an example of the relationship between the Hsync signal and the timer signal.

Hereinafter, the operation will be described in accordance with the flow of FIG. The processing of the monitor control unit is performed when a document is set on the image scanner and a reading instruction is issued from the host computer to the image scanner.
Performed by the PU.

Step S801: The timer value of the back-and-force control for performing the through-down, the back, and the through-up is read from the back-and-force timer value in the nonvolatile memory.

Step S802: The motor timer and the image control circuit are activated to start image reading. When an interrupt signal (timer signal) is generated from the motor timer and this signal is received, an interrupt process not described sends an instruction to switch the excitation phase to the motor driver for each interrupt, and drives the stepping motor. The image data read by the CCD is stored in a memory via an image control circuit, and an interrupt signal (Hsync signal) is generated from the image control circuit every time one line of image data is read.

Step S803: It is determined whether reading of the set document has been completed. If the reading has been completed, the process ends. If the reading has not been completed, the process proceeds to step S804.

Step S804: Determine whether the memory is full of image data. If full, step S80
The process proceeds to step S5, and if not full, returns to step S803.

Step S805: The image control circuit is controlled to stop reading image data.

Step S806: The timer value of the through-down is set in the motor timer to perform the through-down. The total time required for the through-down is set to an integral multiple of the timer value (timer cycle) during normal driving.

Step S807: The back timer value is set in the motor timer to perform the back. The total time required for backing is set to an integral multiple of the timer value (timer cycle) during normal driving.

Step S808: An interrupt signal (timer signal) generated from the motor timer is ignored.
As a result, the stepping motor is stopped without sending an excitation switching instruction to the motor driver in the interrupt processing.

Step S809: It is determined whether the memory is empty. If the memory is empty, the process proceeds to step S810, and if the memory is not empty, the process returns to step S809.

Step S810: An interrupt signal (timer signal) generated from the motor timer is received. As a result, an interrupt process not described sends an instruction to switch the excitation phase to the motor driver for each interrupt, and the stepping motor is driven again.

Step S811: The sum of the time required for the through-down and back, the time required for the through-up to be performed and the stop time for stopping the motor timer is an integral multiple of the image data reading time for each line. After adjusting the stop time so as to set the timer value, the timer value of the through-up is set in the motor timer to perform the through-up. Note that the total time required for the through-up is set to an integral multiple of the timer value (timer cycle) during normal driving.

Step S812: Image reading is restarted. Then, the process returns to step S803.

FIG. 9 is a diagram showing an example of the relationship between the Hsync signal and the timer signal when a start / stop occurs. When the reading speed requires slewing and the read image is large (image data is large), FIG. Step S805
From step S812, an image reading process including back-and-force control and start / stop control is performed.

In this example, since the memory becomes full at T1, the image reading is stopped, and after an interrupt signal (Hsync signal) is received from the image control circuit after T1, through down and back are performed. At T2, the motor timer interrupt signal (timer signal) is ignored. Accordingly, thereafter, no interrupt processing is performed, and no excitation phase switching instruction is sent to the motor driver, so that the stepping motor stops. When it is confirmed at T3 that the memory is empty, the stop time is adjusted so that the sum of the stop time and the through-down, back and through-up times is an integral multiple of the image data reading time for each line. , T4, the motor timer interrupt signal (timer signal) is made valid. As a result, an interrupt process is executed, an excitation switching instruction is sent to the motor driver, and the stepping motor is restarted. Then, through-up is performed, and image reading is restarted.

By performing such processing, the time difference t (arrow A) between the Hsync signal and the timer signal at the time of stop and the time difference t (arrow B) between the Hsync signal and the timer signal at the time of start can be made equal.
That is, the time difference between the timing of starting the image reading and the timing of exciting the stepping motor for moving the reading position can be made the same before the image reading is interrupted and when the image reading is restarted.

Therefore, even when a start / stop occurs, it is possible to obtain an image without any missing or duplicated image at the joint of the images.

[0083]

The present invention is embodied in the form described above, and has the following effects.

In the image scanner device, the time difference between the timing of starting image reading and the timing of excitation for driving the motor can be made the same between before the image reading is interrupted and when the image reading is restarted. In addition, it is possible to provide an apparatus in which images are not displaced at seams due to start-stops that frequently occur with an increase in image data due to the reading density.

Further, even in an image scanner having a reading speed requiring slewing, the time difference between the timing of starting image reading and the timing of excitation for driving the motor differs between before image reading is interrupted and when image reading is restarted. Can be made the same, and it is possible to eliminate the image shift at the joint at the time of start / stop.

Further, it is possible to correct a mechanical shift at the time of resuming reading, and it is possible to eliminate an image shift at a joint at the time of start / stop.

[Brief description of the drawings]

FIG. 1 is an example of a configuration block diagram of an image scanner device of the present invention.

FIG. 2 is a processing flowchart (1) of an embodiment of a motor control unit of the present invention.

FIG. 3 is a diagram (1) illustrating an example of a relationship between an Hsync signal and a timer signal.

FIG. 4 is a diagram (1) of a joint of images when a start / stop occurs.

FIG. 5 is a processing flowchart (2) of an embodiment of the motor control unit of the present invention.

FIG. 6 is a diagram (2) illustrating an example of the relationship between the Hsync signal and the timer signal.

FIG. 7 is a diagram (2) of a joint of images when a start / stop occurs.

FIG. 8 is a processing flowchart (3) of an embodiment of the motor control unit of the present invention.

FIG. 9 is a diagram (3) showing an example of the relationship between the Hsync signal and the timer signal.

FIG. 10 is a configuration block diagram of a conventional image scanner device.

FIG. 11 is a processing flowchart of a conventional motor control unit.

FIG. 12 is a diagram illustrating an example of a relationship between a conventional Hsync signal and a timer signal.

FIG. 13 is a diagram of a joint of images when a conventional start / stop occurs.

[Explanation of symbols]

 1 Image Scanner 101 CCD 102 Image Control Circuit 103 Memory 104 Motor Timer 105 CPU 106 Interface Circuit 107 Stepping Motor 108 Motor Driver 109 ROM

Claims (8)

[Claims] In an image scanner apparatus for reading an image by start / stop control, the timing of starting the image reading and the excitation of a stepping motor for moving the reading position are determined before the image reading is interrupted and when the image reading is restarted. An image scanner device comprising a motor control means for making a time difference from timing the same. 2. A CCD for converting an image into an electric signal, a memory for temporarily storing image data, and an image data transferred from the CCD to a memory. When reading image data for each line, the CPU is interrupted. An image control circuit for sending a signal, a stepping motor for moving the carrier, a motor driver for instructing the excitation phase to drive the stepping motor, and a signal for switching the excitation phase of the motor driver,
A motor timer that sends an interrupt signal to the CPU at the timing of switching the excitation phase; a stepping motor that is driven via a motor driver according to the interrupt signal of the motor timer; and the image reading speed is faster than the image discharging speed; When the data is full, the motor timer is not stopped, and the stepping motor is stopped by ignoring the interrupt signal from the motor timer. 2. The image scanner device according to claim 1, further comprising a CPU that restarts the stepping motor by enabling the interrupt signal. 3. In an image scanner apparatus which reads an image at a reading speed requiring slewing and performs start-stop control, when the image reading is interrupted, the motor is slewed down and backed, and the image reading is resumed. , The total time of back and force control to perform motor through-up,
An image scanner device comprising: a motor control means for setting an integral multiple of a reading time of image data for each line. 4. A CCD for converting an image into an electric signal, a memory for temporarily storing image data, and transferring image data from the CCD to the memory, and interrupting the CPU when reading image data for each line. An image control circuit for sending a signal, a stepping motor for moving the carrier, a motor driver for instructing the excitation phase to drive the stepping motor, and a signal for switching the excitation phase of the motor driver,
A motor timer that sends an interrupt signal to the CPU at the timing of switching the excitation phase, and a normal driving of the stepping motor,
Then, the stepping motor is driven via the motor driver according to the setting of the motor timer at the time of the through-up and the through-down and the interrupt signal of the motor timer, and the image reading speed is faster than the image discharging speed, and the image data in the memory is When full, let the motor slew down and back, then stop the motor timer, then
When the memory becomes vacant due to the discharge of image data, the sum of the time required for through-down and back-up, the time required for through-up to be performed from now on, and the stop time for stopping the motor timer is the image data read for each line. 4. The image scanner device according to claim 3, further comprising: a CPU that performs a through-up after adjusting a stop time so as to be an integral multiple of time. 5. The image scanner device according to claim 2, wherein at the time of resuming reading, a correction value is read from a correction value storage unit for storing a correction value of a mechanical shift, and a reading start position is shifted by the correction value. An image scanner device comprising: 6. A CCD for converting an image into an electric signal, a memory for temporarily storing image data, and transferring image data from the CCD to the memory, and interrupting the CPU when reading image data for each line. An image control circuit for sending a signal, a stepping motor for moving the carrier, a motor driver for instructing the excitation phase to drive the stepping motor, and a signal for switching the excitation phase of the motor driver,
A motor timer for sending an interrupt signal to the CPU at the timing of switching the excitation phase, and a C for driving a stepping motor via a motor driver according to the interrupt signal of the motor timer.
In the start / stop control method in the image scanner device provided with the PU, the image reading speed is higher than the image discharging speed, and when the image data in the memory is full, the motor timer is not stopped and the motor timer is stopped. Start / stop control method in which the stepping motor is stopped by ignoring the interrupt signal of the stepping motor, and then, when the memory becomes empty by discharging the image data, the interrupt signal from the motor timer is enabled to restart the stepping motor. . 7. A CCD for converting an image into an electric signal, a memory for temporarily storing image data, and transferring image data from the CCD to the memory, and interrupting the CPU when reading image data line by line. An image control circuit for sending a signal, a stepping motor for moving the carrier, a motor driver for instructing the excitation phase to drive the stepping motor, and a signal for switching the excitation phase of the motor driver,
A motor timer that sends an interrupt signal to the CPU at the timing of switching the excitation phase, and a normal driving of the stepping motor,
A CPU that drives a stepping motor via a motor driver according to the setting of a motor timer at the time of through-up and through-down and an interrupt signal of the motor timer
In the start / stop control method in the image scanner device provided with the above, when the image reading speed is faster than the image discharging speed and the image data in the memory is full, the motor is slewed down and back, and then the motor timer After that, when the memory becomes empty due to the discharge of image data, the sum of the time required for through-down and back-up, the time required for through-up to be performed from now on, and the stop time for stopping the motor timer is one line. A start-stop control method in which a stop time is adjusted so as to be an integral multiple of the reading time of each image data, and then a through-up operation is performed. 8. The start / stop control method according to claim 6, wherein at the time of resuming reading, a correction value is read from a correction value storage unit for storing a correction value for mechanical deviation, and the reading start position is shifted by the correction value. Start / stop control method.