JP2005080181A - Image reading apparatus and image reading program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an image reading apparatus which is driven for each time of line reading to reduce power consumption of a stepping motor. <P>SOLUTION: An image reading apparatus 2 includes a CPU 11, a memory 12A, a ROM 12B, an I/F circuit 13, an LED drive circuit 14, a signal processing circuit 15, an A/D converter 16, an optical block motor drive circuit 17, a CCD drive circuit 18, an optical block 19, and an optical block motor 20. The CPU 11 repeatedly moves the optical block 19 for one line and reads one line (an excitation pattern is bi-phase excitation). The CPU 11 reduces a current to flow through a coil of the optical block motor 20 when the reading operation is not completed until a predetermined time T1, and turns off the current to flow through the coil of the optical block motor 20 when an READ command is not received until a predetermined time T2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus and a program for the apparatus.

  An image reading apparatus that reads a document line by line in the main scanning direction while driving a stepping motor to move the relative position between the document and the line sensor in the sub-scanning direction is known (for example, see Patent Document 1). Patent Document 1 discloses a technique in which when one reading scan is completed, the optical unit is moved to the start position of the next reading scan, and the excitation current supplied to the motor is reduced to enter the hold state.

JP 2000-115455 A

  In general, scanning for reading a document repeatedly performs an operation of moving the optical unit by one line every time one line of data is read. The stepping motor stops once the optical unit is moved by one line, and waits for movement to the next line. There is a case where it is desired to reduce the excitation current even in such a temporarily stopped state. During line reading, it is necessary to control the excitation current applied to the stepping motor so that the read image does not deteriorate.

An image reading apparatus according to the present invention includes an imaging unit that captures an image of a document line by line, a line moving unit that moves a relative position of the document and the imaging unit with a motor corresponding to the line to be imaged, and imaging of one line by the imaging unit. Imaging determination means for determining whether or not the image has ended, and when the line moving means moves the relative position corresponding to the next line, current is supplied to the motor at the first current value, and the imaging determination means terminates the imaging. Current control means for changing to a second current value smaller than the first current value before the determination.
The current control means changes the current value to the second current value when the relative position has elapsed after the start of movement of one line is equal to or longer than the first determination time, and changes to the first current value when the elapsed time is less than the first determination time. The current value can be maintained.
The current control means sets the supply current to 0 when the elapsed time is equal to or longer than the second determination time longer than the first determination time, and maintains the second current value when the elapsed time is less than the second determination time. You can also. In this case, the current control means may supply current to the motor in a two-phase excitation pattern, or may set the supply current to 0 after changing from the two-phase excitation pattern to the one-phase excitation pattern.
The image reading apparatus may further include a line processing determination unit that determines whether or not the processing for one line of imaging data captured by the imaging unit is completed. When the line processing determination unit determines the end of processing, The control unit may supply current at the first current value, and the line moving unit may be configured to move the relative position corresponding to the next line.
An image reading program according to the present invention includes a process for instructing an imaging unit that images a document line by line to start imaging of each line, and a motor that moves a relative position between the document and the imaging unit corresponding to the line to be imaged. A process for instructing the start of movement, a line imaging end determination process for determining whether or not the imaging of one line by the imaging unit has been completed, and a process for the motor to move the relative position corresponding to the next line. A process for instructing to supply a current having a current value of 1, and a process for instructing to change the supply current to a second current value smaller than the first current value before the end of line imaging is determined. It is executed by the CPU.

  According to the present invention, it is possible to reduce the power consumption of a stepping motor that drives each time a line is read by the image reading apparatus.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram illustrating an image reading apparatus according to an embodiment of the present invention. In FIG. 1, the image reading apparatus 2 and the host computer 1 constitute an image reading system. The image reading system reads an image such as a film original and obtains electronic image data. The image reading device 2 and the host computer 1 are connected via an interface cable (not shown), and operations on the image reading system are performed from the host computer 1. The host computer 1 is composed of a personal computer or the like, and includes a CPU, a memory, a hard disk drive (HDD), a display monitor, and an operation member.

  The image reading device 2 includes a CPU 11, a memory 12A, a ROM 12B, an external interface circuit (hereinafter referred to as I / F circuit) 13, an LED drive circuit 14, a signal processing circuit 15, and an A / D converter 16. The optical block motor drive circuit 17, the CCD drive circuit 18, the LED illumination 19a, the lens 19b, the CCD 19c, and the optical block motor 20 are included. Among these, the LED illumination 19a, the lens 19b, and the CCD 19c constitute an optical block 19 of the image reading device 2.

  The CPU 11 communicates with the host computer 1 via the I / F circuit 13 and controls each block of the image reading device 2. The memory 12A is used as a work area for the CPU 11, and is also used as an area for temporarily storing various reading conditions set when the film original F is read, read image data, and the like. The ROM 12B stores program data executed by the CPU 11 and the like.

  The I / F circuit 13 is a circuit for performing communication between the CPU 11 and the host computer 1. The CPU 11 receives a command transmitted from the host computer 1 via the I / F circuit 13, while reading image data stored in the memory 12A, information on the image reading device 2 stored in the memory 12A, and the like. Is transmitted to the host computer 1.

  The LED drive circuit 14 controls the light emission of the LED illumination 19a that illuminates the film original F. The LED illumination 19a has light sources of three colors of red R, green G, and blue B, and is configured to be able to emit light by switching the light sources of these colors, or to simultaneously emit light of a plurality of colors. Yes. The illumination light emitted from the LED illumination 19a is configured to illuminate a width corresponding to one reading line on the reading surface of the film original F. The film document F may be a negative film, a reversal film, or a long film of each.

  The light transmitted through the film original F enters the lens 19b. The transmitted light incident on the lens 19b is collected by the lens 19b and incident on the CCD 19c. The CCD 19c includes a CCD line sensor in which a plurality of photoelectric conversion elements are arranged on a line in the main scanning direction for scanning the film document F. Each element constituting the CCD 19c accumulates electric charge according to the intensity of incident light. The operation timing and charge accumulation time of these elements are controlled by the CCD drive circuit 18. The charge accumulation time is determined by a command sent from the CPU 11 to the CCD drive circuit 18. When the charge accumulation of the CCD 19c is completed, the accumulated charge accumulated in each element is output as an imaging signal.

  The signal processing circuit 15 performs analog processing such as CDS (correlated double sampling), shading correction, dark current correction, and even / odd correction on the analog image signal. The analog processed signal is A / D converted into digital image data by the A / D converter 16 and stored in the memory 12A as line data. Data stored in the memory 12 </ b> A is read according to a command from the CPU 11 and sent to the host computer 1 via the I / F circuit 13.

  The optical block motor drive circuit 17 rotates the optical block motor 20 in accordance with a command from the CPU 11 to move the optical block 19 in a direction orthogonal to the pixel row of the CCD 19c (the left-right direction in FIG. 1), thereby sub-scanning at the time of image reading. Scan. In sub-scanning, in order to image the film original F with the CCD 19c, the relative position of the optical block 19 with respect to the film original F is moved by one line every time one line is imaged with the CCD 19c. While the optical block 19 is sub-scanned, the CCD 19c repeats the main scanning in which the image is taken line by line, whereby the film document F is imaged (image read) by the CCD 19c.

  The optical block motor drive circuit 17 has a constant current drive corresponding to microsteps, and is configured to be able to vary the excitation pattern and current value of the optical block motor 20. The excitation pattern will be described later.

  The host computer 1 receives line data for each predetermined number of lines from the image reading device 2 via the I / F circuit 13. When the host computer 1 receives line data of the number of lines constituting the reading range (for example, one frame) of the film document F, the host computer 1 generates read image data of one frame using these line data, and the host computer 1 To the HDD.

In the image reading system described above, reading (scanning) of the film document F is performed according to the following procedure.
1. 1. Load film original F Pre-scan (reference image reading)
3. 3. Reading condition setting Main scan (main image reading)

  The pre-scan is image reading performed before the main scan in order to obtain a reference image. The reference image is a coarse reading image that is used when the operator confirms the reading range, or that the host computer 1 uses to obtain reading conditions such as exposure.

  The present invention is characterized by drive control (rotation control) of the optical block motor 20 in sub-scanning at the time of scanning performed by the image reading device 2.

  As described above, the optical block 19 is moved by one line every time one image of the film original F is imaged during sub-scanning. For example, when the reading range of the film document F is divided into N lines and read, the movement of the optical block 19 for one line and the reading of one line are repeated N times. If the optical block 19 moves during image reading, image displacement occurs, leading to degradation of the read image. Therefore, the optical block motor 20 stops once the optical block 19 is moved by one line, and reading of the line ends. The optical block 19 is further moved by one line for reading the next line.

  The drive pulse signal applied to the optical block motor 20 by the optical block motor drive circuit 17 will be described. The optical block motor 20 has A-phase and B-phase excitation coils, respectively. The A-phase and B-phase coils are excited when a current is applied. The optical block motor 20 is driven and controlled by sequentially switching the exciting coils in accordance with the rotation of the rotor. Changes in the current flowing through the A-phase and B-phase coils are called excitation patterns, and a plurality of patterns are known as follows.

(A) 1-phase excitation (B) 2-phase excitation (C) 1-2-phase excitation (D) W1-2-phase excitation

  In the one-phase excitation, an exciting current is supplied to one of the coils of the A phase and the B phase, and the coil and the direction of the current for supplying the exciting current are sequentially switched in a time division manner. FIG. 2 is a diagram for explaining a current vector for one-phase excitation. In FIG. 2, the horizontal axis represents the A phase, and the vertical axis represents the B phase, which represents 3/4 cycles. The numerical value in parentheses written in each vector represents the excitation order. In one-phase excitation, one pattern of excitation current flows per 1/4 cycle. The optical block motor drive circuit 17 supplies a drive pulse signal to the optical block motor 20 so that such an excitation current flows through the excitation coil during one-phase excitation.

  In the two-phase excitation, an excitation current is supplied to both the A-phase and B-phase coils, and the direction in which the excitation current is supplied (current vector direction) is sequentially switched in a time division manner. FIG. 3 is a diagram for explaining a current vector of two-phase excitation. In FIG. 3, the horizontal axis represents the A phase, the vertical axis represents the B phase, and represents the ½ cycle. The numerical value in parentheses written in each vector represents the excitation order. In the two-phase excitation, one pattern of excitation current flows per 1/4 cycle. The optical block motor drive circuit 17 supplies a drive pulse signal to the optical block motor 20 so that such an excitation current flows through the excitation coil during two-phase excitation.

  For 1-2 phase excitation, the excitation current is passed through the coils of A phase only, A phase and B phase, B phase only, A phase and B phase, A phase only ..., and the direction and magnitude of the current vector are time-divided. It is to switch with. FIG. 4 is a diagram for explaining a current vector of 1-2 phase excitation. In FIG. 4, the horizontal axis represents the A phase, the vertical axis represents the B phase, and represents 1/4 cycle. The numerical value in parentheses written in each vector represents the excitation order. In 1-2 phase excitation, two patterns of excitation current flow per quarter cycle. The optical block motor drive circuit 17 supplies a drive pulse signal to the optical block motor 20 so that such excitation current flows through the excitation coil during 1-2 phase excitation.

  In W1-2 phase excitation, excitation current is passed through the coils of A phase only, A phase and B phase, B phase only, A phase and B phase, A phase only ..., and the direction and magnitude of the current vector are time-shared. It is to switch with. FIG. 5 is a diagram for explaining a current vector of W1-2 phase excitation. In FIG. 5, the horizontal axis represents the A phase, and the vertical axis represents the B phase, which represents a quarter cycle. The numerical value in parentheses written in each vector represents the excitation order. The vectors (1) to (3) indicate that the cycle division is performed by changing the ratio of the currents flowing through the A-phase and B-phase coils simultaneously. In the W1-2 phase excitation, four patterns of excitation current flow per quarter cycle. The optical block motor drive circuit 17 supplies a drive pulse signal to the optical block motor 20 so that such excitation current flows through the excitation coil during W1-2 phase excitation.

  In addition to the above description, there are 2W1-2 phase excitation in which 8 patterns of excitation current are applied per 1/4 cycle and 4W1-2 phase excitation in which 16 patterns of excitation current are applied per 1/4 cycle. However, the description is omitted here. To do.

  In the present embodiment, the optical block motor 20 is usually driven by two-phase excitation. The CPU 11 outputs a command to the optical block motor drive circuit 17 so as to perform the two-phase excitation (B).

  FIG. 6 is a flowchart for explaining the flow of processing executed by the CPU 11 of the image reading apparatus 2. In step S11 of FIG. 6, the CPU 11 receives a SCAN command (scan start command) transmitted from the host computer 1, and proceeds to step S12. If no SCAN command is received, the process does not proceed to step S12.

  In step S12, the CPU 11 sets a reading condition (for example, an exposure time) based on information from the host computer 1, and proceeds to step S13. In step S <b> 13, the CPU 11 sends a command to the optical block motor drive circuit 17 to move the optical block 19 to the reading start position of the document F. The optical block motor drive circuit 17 sends a predetermined number of pulse signals to the optical block motor 20, whereby the optical block moves to the reading start position. As described above, the excitation pattern of the excitation current supplied to the optical block motor 20 is two-phase excitation. In order not to shift the position of the optical block 19 after the movement, a current is continuously supplied to both the A phase and B phase coils of the optical block motor 20 (excitation ON).

  In step S14, the CPU 11 causes a timer circuit (not shown) to start measuring time and proceeds to step S15. In step S15, the CPU 11 starts a reading operation for one line and proceeds to step S16. Thereby, the LED drive circuit 14 performs light emission control of the LED illumination 19a, and the CCD drive circuit 18 performs imaging control of the line sensor 19c. In step S16, when the CPU 11 is set to transmit read data for each line to the host computer 1, the CPU 11 starts a process of transferring the read data to the host computer 1 and proceeds to step S17. If the read data is set to be transmitted to the host computer 1 every predetermined number of lines, the transfer start is instructed only when the read line number reaches the predetermined number, and the predetermined number is not reached. Proceeds directly to step S17.

  In step S17, the CPU 11 determines whether or not the reading operation has not been completed within a predetermined time T1. The CPU 11 makes an affirmative determination in step S17 when the reading operation is not completed at the time when the predetermined time T1 is counted, and proceeds to step S18. If the reading operation is completed, the CPU 11 makes a negative determination in step S17. Proceed to S19. The reading operation is an operation until imaging of at least one line of red R, green G, and blue B is completed.

  In step S18, the CPU 11 sends a command to the optical block motor drive circuit 17 to reduce (for example, change to 2/3) the current flowing through both the A-phase and B-phase coils of the optical block motor 20, and then proceed to step S19. move on.

  In step S19, the CPU 11 determines whether a READ command has not been received within the predetermined time T2. The predetermined time T2 is set to a time sufficient for normal reading operation and transfer operation. When the CPU 11 has not received a READ command (a signal indicating that it is ready to receive the next line data) from the host computer 1 at the time of measuring the predetermined time T2, the CPU 11 makes an affirmative determination in step S19 and proceeds to step S20. If the READ command has been received, a negative determination is made in step S19 and the process proceeds to step S22. The READ command is transmitted from the host computer 1 when the host computer 1 finishes receiving the read data transferred from the image reading device 2.

In step S20, the CPU 11 sends a command to the optical block motor drive circuit 17, stops the currents flowing through both the A-phase and B-phase coils of the optical block motor 20 (excitation OFF), and proceeds to step S21. The CPU 11 turns off the excitation according to the following procedure.
(A) Switch from 2-phase excitation to 1-phase excitation.
(B) The current flowing through the A-phase (B-phase) coil is set to 0 (stop).

  In step S21, the CPU 11 determines whether a READ command has been received. When the CPU 11 receives a READ command from the host computer 1, the CPU 11 makes a positive determination in step S21 and proceeds to step S22. When the CPU 11 does not receive a READ command, the CPU 11 makes a negative determination in step S21 and repeats the determination processing.

  In step S22, the CPU 11 determines whether or not a predetermined number of line readings have been completed. The CPU 11 makes an affirmative decision in step S22 when all the line readings within the reading range have been completed, and ends the process of FIG. On the other hand, the CPU 11 makes a negative determination in step S22 when a line that has not been read remains in the reading range, and proceeds to step S23.

  In step S23, the CPU 11 sends a command to the optical block motor drive circuit 17 to return the currents flowing in both the A-phase and B-phase coils of the optical block motor 20 to the normal current values in step S13 and then to step S24. move on. CPU11 returns an electric current value in the following procedures. If the excitation is not turned off or the current value is not decreased, the current value at step S13 is set to the initial value without changing the excitation pattern. If the excitation is OFF, the mode is switched to two-phase excitation and the signal of the last pulse before the excitation OFF is supplied to the optical block motor 20 with the normal current value at the beginning of step S13, and then the process proceeds to step S24.

  In step S24, the CPU 11 sends a command to the optical block motor drive circuit 17, causes the optical block motor 20 to supply a predetermined number of pulses necessary for moving one line, and returns to step S14. As a result, the CPU 11 sends a command to the optical block motor drive circuit 17 so as to move the optical block 19 to a position corresponding to the next one line. When the optical block motor drive circuit 17 sends the number of pulse signals necessary for the movement of one line to the optical block motor 20, the optical block starts to move. Further, the CPU 11 resets the time measured by the timer circuit and repeats the line reading process after step S14.

According to the embodiment described above, the following operational effects can be obtained.
(1) Every time one line is read, the image reading device 2 determines whether or not the reading operation has been completed by a predetermined time T1 (step S17). If the reading operation has not been completed, the coil of the optical block motor 20 is determined. The current to be supplied to is reduced (step S18). Therefore, when the density of the film original F is high, or when multi-sample scanning is performed in which one line is read a plurality of times to obtain the average value of the read data, the temporary stop time of the optical block 19 is longer than the normal line reading. In this case, power consumption can be reduced. Further, since the current is not set to 0 (excitation is not turned OFF), the position of the optical block 19 during the line reading is maintained, and the read image does not deteriorate image quality such as image shift.

(2) The image reading device 2 determines whether or not a READ command has been received by the predetermined time T2 every time one line is read (step S19), and if it has not been received, the coil of the optical block motor 20 The current to be passed through is turned off (step S20). Therefore, it is necessary to delay the start of reading the next line due to a decrease in the data transfer speed by the I / F circuit 13, and the power consumption when the stop time of the optical block 19 is extended longer than that during normal data transfer. And the heat generation by the optical block motor 20 (especially a coil) can be suppressed. Since it can be considered that the reading of the line has been completed after the predetermined time T2 has elapsed, the position of the optical block 19 may be slightly moved by excitation OFF.

(3) When the excitation is turned off in (2) above, the current flowing through the A-phase (B-phase) coil is set to 0 after switching from 2-phase excitation to 1-phase excitation. The moving direction of the block 19 (that is, the rotating direction of the optical block motor 20) can be made constant. In general, when excitation OFF is performed during two-phase excitation, the excitation position (corresponding to the vector direction in FIG. 3) when the rotor of the optical block motor 20 is two-phase excitation is changed to the excitation position (in FIG. 2). Move to the vector direction). At this time, it moves in the CW direction or moves in the CCW direction depending on individual differences of motors. If the optical block motor 20 is energized again and the rotor position is moved to the excitation position for two-phase excitation, the rotor position (ie, the position of the optical block 19) may not match before and after excitation OFF. Arise. However, if the current flowing through the coil is set to 0 after switching from 2-phase excitation to 1-phase excitation as in this embodiment, the motor rotor is always in a constant direction during excitation ON, regardless of individual motor differences. The position of the rotor matches before and after excitation OFF. As a result, occurrence of image shift can be suppressed.

(4) When the motor current value is restored after excitation OFF (step S23), the signal of the last pulse before excitation OFF is supplied to the optical block motor 20 with the current value at step S13, and the process proceeds to step S24. I made it. Thereby, since the position of the rotor can be surely matched before and after excitation OFF, there is no deterioration of the read image due to image displacement, and a high-quality read image can be obtained.

  The above (1) and (2) are not limited to the two-phase excitation but may be applied to other excitation methods.

  When the movement of the optical block 19 is started by one line (step S24), the predetermined time T1 is counted, and at this time (step S17), it is determined whether or not the reading operation is finished before the imaging of one line is finished. It was detected. Instead, it may be detected before the end of imaging of one line by determining whether or not the CCD drive circuit 18 and the signal processing circuit 15 are operating.

  When the optical block 19 starts moving one line (step S24), a predetermined time T2 is counted, and transfer processing (for one line of imaged data is determined by determining whether or not a READ command is received at this point (step S19). It was detected that the process was not completed. Instead, it may be detected before the end of the transfer process by determining whether the I / F circuit 13 is operating.

  In the above description, an example of an image reading apparatus that reads a color image has been described. However, the present invention may be applied to an apparatus that reads a monochrome image. The reading operation in this case is an operation until imaging of one line is completed under predetermined light.

  It is also possible to prepare the program for performing the image reading described above in each of the image reading apparatus 2 and the host computer 1, and to use these programs after being loaded into the image reading apparatus 2 or the host computer 1. In this case, the ROM 12B of the image reading device 2 and the data storage device of the host computer 1 are each loaded with a program and executed to use it as an image reading system. The program may be loaded by setting a recording medium in which the program is stored in the image reading device 2 or the host computer 1 or by a method via an electric communication line such as a network.

  Correspondence between each component in the claims and each component in the best mode for carrying out the invention will be described. The imaging means is constituted by an optical system block 19, for example. The line moving means is constituted by, for example, the optical block motor driving circuit 17 and the optical block motor 20. The imaging determination unit and the line processing determination unit are configured by the CPU 11, for example. The current control means is constituted by, for example, the CPU 11 and the optical block motor drive circuit 17. The first determination time corresponds to, for example, a predetermined time T1. For example, the predetermined time T2 corresponds to the second determination time. The processing for one line of imaging data includes data transfer processing to the host computer 1. In addition, unless the characteristic function of this invention is impaired, each component is not limited to the said structure.

1 is a block diagram illustrating an image reading apparatus according to an embodiment of the present invention. It is a figure explaining the electric current vector of 1 phase excitation. It is a figure explaining the current vector of two-phase excitation. It is a figure explaining the electric current vector of 1-2 phase excitation. It is a figure explaining the current vector of W1-2 phase excitation. It is a flowchart explaining the flow of the process performed by CPU.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Host computer 2 ... Image reading apparatus 11 ... CPU
12A ... Memory 12B ... ROM
DESCRIPTION OF SYMBOLS 13 ... I / F circuit 14 ... LED drive circuit 15 ... Signal processing circuit 16 ... A / D converter 17 ... Optical block motor drive circuit 18 ... CCD drive circuit 19 ... Optical block 20 ... Optical block motor F ... Film original

Claims (7)

Imaging means for imaging a document line by line;
Line moving means for moving the relative position of the document and the imaging means with a motor corresponding to the line to be imaged;
Imaging determination means for determining whether or not the imaging of one line by the imaging means has been completed;
When the line moving means moves the relative position corresponding to the next line, a current is supplied to the motor at a first current value, and the first current before the imaging determination means determines the end of imaging. An image reading apparatus comprising: current control means for changing to a second current value smaller than the value. The image reading apparatus according to claim 1,
The current control means changes the second current value when the time elapsed after the relative position has started after moving one line is equal to or longer than the first determination time, and the elapsed time is less than the first determination time. In this case, the image reading apparatus maintains the first current value. The image reading apparatus according to claim 2,
The current control means sets the supply current to 0 when the elapsed time is equal to or longer than a second determination time longer than the first determination time, and sets the supply current to 0 when the elapsed time is less than the second determination time. An image reading apparatus that maintains a current value of 2. The image reading apparatus according to claim 3.
The image reading apparatus, wherein the current control means supplies the current to the motor in a two-phase excitation pattern. The image reading apparatus according to claim 4,
The image reading apparatus according to claim 1, wherein the current control unit sets the supply current to 0 after changing from the two-phase excitation pattern to the one-phase excitation pattern. In the image reading apparatus in any one of Claims 1-5,
Line processing determining means for determining whether or not processing for one line of imaging data imaged by the imaging means has been completed;
When the line processing determination means determines the end of the processing, the current control means supplies current at the first current value, and the line moving means moves the relative position corresponding to the next line. An image reading apparatus. Processing for instructing the imaging means for imaging the document line by line to start imaging each line;
A process for instructing movement start of a motor that moves the relative position of the document and the imaging unit corresponding to the line to be imaged;
A line imaging end determination process for determining whether or not the imaging of one line by the imaging means is completed;
A process for instructing the motor to supply a current of a first current value when the motor moves the relative position corresponding to the next line;
An image reading program, wherein the CPU executes processing for instructing to change the supply current to a second current value smaller than the first current value before the end of line imaging is determined.

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