JP2001217996A - Scanner and start stop control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that in a conventional scanner, the entire read performance deteriorates due to an extended moving time up to a read restart position because the carrier of the scanner is returned temporarily in a subscanning start direction after a stop, moved again in the subscanning direction at restart to a read stop position and reading is restarted in order to bring joints between images at the reading stop and the restart into a natural state and because the carrier is moved in the subscanning direction at a speed same as the image reading speed in order to match a motor drive signal of a motor to move the carrier with an image read signal at restart of image reading. SOLUTION: The scanner is provided with a means that settles the motor in a setting time set to each read mode and accelerates the motor up to a maximum speed, decelerates the motor and drives the motor at a reading speed so as to move the carrier up to the read restart position when the carrier is moved to the read restart position in order to restart reading after the reading stop.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flatbed type scanner for reading by moving a carrier on which a reading unit for reading an image by an image reading sensor (CCD) is mounted in a sub-scanning direction by driving a motor. In particular, the present invention relates to a start / stop control method, and in particular, after the free space of a buffer memory for temporarily storing read image data becomes less than a predetermined value and reading is stopped, the image data is transferred to a host computer to buffer the read image data. When the free space in the memory exceeds a predetermined value and the carrier is moved to the reading restart position to restart reading, the motor is settled at the preset settling time for each reading mode, and the motor is accelerated, fastest, and decelerated. Then, drive at the reading speed and move the carrier to the reading restart position Means provided for, improve the reading performance.

[0002] In this specification, the term "start / stop control" is used to stop or restart the reading operation and the movement of the carrier according to the availability of a buffer memory for temporarily storing read image data. Control.

[0003]

2. Description of the Related Art A flatbed type scanner device for reading by moving a carrier on which a reading unit is mounted in a sub-scanning direction by driving a motor has temporary storage means called a buffer memory in the scanner device. Is stored in the buffer memory. When the free space in the buffer memory is reduced and becomes less than a predetermined value, the image reading operation is temporarily stopped, and the free space in the buffer memory is increased by transferring the image data to the host computer. , The image reading operation is restarted.

Further, in order to make the seam of the image at the time of stopping and resuming the reading operation natural, the carrier is stopped, then temporarily returned to the sub-scanning start direction, and moved again in the sub-scanning direction at the time of resuming. It is returned to the stopped position and reading is resumed from there.

FIG. 5 shows a processing flowchart of an embodiment of a conventional image reading control section. Hereinafter, the operation will be described according to the flow of FIG.

The processing of the image reading control unit is executed by the CPU when a document is set on the scanner and a reading instruction is issued from the host computer to the scanner.

Step S501: Image reading is started.

Step S502: 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 S503.

Step S503: Determine whether the free space in the buffer memory is less than a predetermined value. If it is less than the predetermined value, the process proceeds to step S504, and if not, the process returns to step S502.

Step S504: Image reading is stopped. Then, in preparation for reading resumption, the carrier is returned to the temporary sub-scanning start direction.

Step S505: It is determined whether the free space in the buffer memory is equal to or larger than a predetermined value. If the value is equal to or more than the predetermined value, the process proceeds to step S506, and if not, the process returns to step S505.

Step S506: A reading restart position (reading stop position) of the carrier moved in the temporary sub-scanning start direction.
In order to move the carrier, the settling (turning the stepping motor into an excited state) is performed before driving the stepping motor that operates the carrier.

Step S507: The stepping motor is driven at the reading speed, and the carrier is moved to the reading restart position (read stopping position).

Step S508: Image reading is restarted. Then, the process returns to step S502.

FIG. 6 shows a relational diagram between a conventional read signal and a motor drive signal. The read signal is a timing signal for reading image data from the CCD provided on the carrier, and the motor drive signal is a timing signal for driving a stepping motor for moving the carrier. Also,
This relationship diagram is from when the buffer memory becomes empty and reading is resumed, and shows steps S506 to S508 in FIG.

In this example, the settling time is set to be the same as the period of the read signal, and the stepping motor is driven so that the carrier moves at the same speed as the read speed. Are aligned.

[0017]

However, the prior art shown in FIG. 5 has the following problems. (1) When resuming image reading, it is necessary to match the motor drive signal of the motor for moving the carrier with the image reading signal in order to make the seam of the image natural at the boundary between the stop and restart of the reading operation. There is. For this reason, the operation of moving the carrier in the sub-scanning direction is performed at the same speed as the image reading speed, and it takes a long time to move the carrier to the reading restart position (reading stop position), which deteriorates the overall reading performance. .

(2) If the operation of moving the carrier in the sub-scanning direction is to be performed at the highest speed of the motor operation, when the image reading is resumed, the matching between the motor drive signal of the motor for moving the carrier and the image reading signal is performed. It cannot be removed, and the joint becomes unnatural, or the length of the entire image fluctuates.

[0019]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has a flatbed in which a carrier on which a reading unit is mounted is moved by driving a motor in a sub-scanning direction to perform reading. When the free space in the buffer memory for temporarily storing the read image data is less than a predetermined value and reading is stopped, the image data is transferred to the host computer and the free space in the buffer memory is When the carrier is moved to the read resume position to resume reading, the motor is settled at a preset settling time for each read mode, and the carrier is moved to the read resume position at the highest speed. Improve reading performance.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a flatbed type scanner device for reading by moving a carrier on which a reading unit is mounted in a sub-scanning direction by driving a motor, a free space in a buffer memory for temporarily storing a read image. And a reading control unit that stops reading an image when the free space detecting unit detects a shortage of free space and resumes reading an image when it detects that free space has been secured. When the free space detection unit detects that the free space is insufficient, the motor is stopped, and when it is detected that the free space is secured, the motor is settled at a preset settling time for each reading mode, and the motor is set. By providing a motor control unit that drives the motor at the highest speed, the lowest speed, the lowest speed, and the reading speed, the reading performance can be greatly improved. It is possible.

In a start / stop control method in a flatbed type scanner device for reading by moving a carrier on which a reading unit is mounted in a sub-scanning direction by driving a motor, a buffer memory for temporarily storing read image data is provided. After the free space becomes less than the predetermined value and reading is stopped, the image data is transferred to the host computer, the free space in the buffer memory becomes more than the predetermined value, and the carrier is moved to the reading restart position to restart reading. When the motor is settled at the preset settling time for each reading mode, the motor is accelerated, driven at the highest speed, decelerated, and then driven at the reading speed, and the carrier is moved to the reading restart position, thereby greatly improving the reading performance. It can be improved.

[0022]

FIG. 1 is a block diagram showing an example of the configuration of a scanner device according to the present invention. In FIG. 1, reference numeral 1 denotes a scanner connected to a host computer. The scanner 1 includes a CCD 101 for converting an image into an electric signal, a buffer memory 103 for temporarily storing image data, and a CCD 101.
Is transferred to the buffer memory 103, and
An image control circuit 102 for sending a read signal to the CPU 105 when reading image data for each line;
03, an interface circuit 106 for transferring the image data to the host computer as needed, a stepping motor 107 for moving the carrier, a motor driver 108 for instructing the excitation phase to drive the stepping motor 107, and a stepping motor via the motor driver 108. 107
And the image reading speed is faster than the image data transfer speed to the host computer, and the buffer memory 103
The CPU 105 stops the stepping motor 107 when the image data in the memory becomes less than the predetermined value, and then restarts the stepping motor when the buffer memory 103 becomes more than the predetermined value by transferring the image data to the host computer. And a settling time setting table in which the settling time when the stepping motor is re-driven is set, and a free space which is activated by the CPU 105 when the power is turned on and detects a free space in a buffer memory for temporarily storing read images. A reading control unit 109 that stops reading an image when the detecting unit 1091 and the free space detecting unit 1091 detect insufficient free space and restarts reading an image when detecting that free space is secured.
2. When the free space detection unit 1091 detects that the free space is insufficient, the motor is stopped, and when it is detected that the free space is secured, the motor is settled for a preset settling time for each reading mode. Accelerate the
ROM 1 storing a program such as a motor control unit 1093 for driving at the highest speed, deceleration, and reading speed
09 is provided.

Referring to FIGS. 2 and 3, the operation of the image reading control unit will be described. FIG. 2 is a processing flowchart of an embodiment of the image reading control unit of the present invention, and FIG. 3 is an embodiment diagram of a settling time setting table.

The settling time setting table 31 shown in FIG. 3 includes a reading mode and a settling time. The time required to resume reading is determined by the settling time of the motor and the moving time of the carrier. When the settling time is adjusted and the carrier is moved at the fastest speed (the motor is accelerated, fastest, decelerated, and driven at the reading speed) The settling time adjusted for each read mode is set so that the read signal and the motor drive signal at the time of restart of reading can be matched at the time of reading.

The operation will be described below with reference to the flow chart of FIG. The processing of the image reading control unit is executed by the CPU when a document is set on the scanner device and a reading instruction is issued from the host computer to the scanner device. In addition, a reading mode is set for the reading instruction.

Step S201: Image reading is started.

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: It is determined whether the free space of the buffer memory is less than a predetermined value. If it is less than the predetermined value, the process proceeds to step S204, and if not, the process returns to step S202.

Step S204: Reading of the image is stopped. Then, in preparation for reading resumption, the carrier is returned to the temporary sub-scanning start direction.

Step S205: It is determined whether the free space in the buffer memory is equal to or larger than a predetermined value. If the value is equal to or more than the predetermined value, the process proceeds to step S206, and if not, the process returns to step S205.

Step S206: A reading restart position (reading stop position) of the carrier moved in the temporary sub-scanning start direction.
Before the stepping motor driving the carrier is driven, the settling time corresponding to the reading mode is obtained from the settling time setting table, and settling is performed using the settling time.

Step S207: The stepping motor is driven at the acceleration, the highest speed, the deceleration, and the reading speed, and the carrier is moved to a position before the reading restart position (reading stop position).

Step S208: The stepping motor is driven at the reading speed, and the carrier is moved to the reading restart position (read stopping position).

Step S209: Reading of the image is restarted. Then, the process returns to step S202.

By performing such processing, when the carrier is moved to the reading restart position to resume reading after the reading is stopped, the carrier can be moved to the reading restart position at the highest speed, and the reading performance is greatly improved. Can be improved.

FIG. 4 shows an example of the relationship between the read signal and the motor drive signal according to the present invention. The read signal is a timing signal for reading image data from the CCD provided on the carrier, and the motor drive signal is a timing signal for driving a stepping motor for moving the carrier. This relationship diagram is from when the buffer memory becomes empty and reading is resumed. FIG. 4A shows steps S206 to S209 in FIG.

FIG. 4A shows an example in which the carrier movement is performed at the highest speed, and it can be seen that the time for resuming the reading is shortened by t time compared to the example in which the carrier movement is performed at the reading speed in FIG. 4B. .

[0038]

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

In the start / stop control, the carrier can be moved to the reading restart position at the highest speed.
The reading performance can be greatly improved. Further, it is possible to obtain an image in which the seams of the images are natural and the entire length is normal.

[Brief description of the drawings]

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

FIG. 2 is a processing flowchart of an embodiment of an image reading control unit of the present invention.

FIG. 3 is a diagram illustrating an example of a settling time setting table.

FIG. 4 is a diagram illustrating an example of a relationship between a read signal and a motor drive signal according to the present invention.

FIG. 5 is a processing flowchart of an embodiment of a conventional image reading control unit.

FIG. 6 is a relationship diagram between a conventional read signal and a motor drive signal.

[Explanation of symbols]

 1 scanner device 101 CCD 102 image control circuit 103 buffer memory 105 CPU 106 interface circuit 107 stepping motor 108 motor driver 109 ROM

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/107 H04N 1/10 1/21

Claims (2)

[Claims] 1. A flat bed type scanner device for reading by moving a carrier on which a reading unit is mounted in a sub-scanning direction by driving a motor, and detecting a free space of a buffer memory for temporarily storing a read image. The free space detecting unit (1091) to stop reading the image when the free space detecting unit (1091) detects the shortage of the free space and restarts the image reading when detecting that the free space is secured. Reading control unit (1
092), the motor is stopped when the free space detection unit (1091) detects the shortage of the free space, and the motor is stopped for a preset settling time for each reading mode when the free space is detected. Settling
A scanner device comprising: a motor control unit (1093) that drives a motor at acceleration, maximum speed, deceleration, and reading speed. 2. A start / stop control method in a flatbed type scanner device for performing reading by moving a carrier on which a reading unit is mounted in a sub-scanning direction by driving a motor, wherein a buffer for temporarily storing read image data is provided. After reading stops when the free space of the memory becomes less than the specified value,
When the image data is transferred to the host computer and the free space in the buffer memory exceeds a predetermined value, and the carrier is moved to the reading restart position in order to restart reading, the motor is driven for a preset settling time for each reading mode. A start-stop control method in which after settling, the motor is accelerated, driven at the highest speed, decelerated, and driven at the reading speed to move the carrier to the reading restart position.