JP2014150357A - Image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a stop period for which transport of a document sheet is stopped while being transported in an image reading device for reading a document sheet by transporting it using a motor.SOLUTION: In a multifunction machine 1, when a temperature Y of a motor is detected to be higher than or equal to a reference temperature YK, transport of a document sheet is suspended until the temperature Y of the motor drops to less than a resumption reference temperature YS. When the temperature Y of the motor is less than the reference temperature YK, the document sheet is transported. The multifunction machine 1 is designed in such a way that the document sheet is transported by a series of operations including a transport operation for transporting the document sheet and a stop operation for causing the transport of the document sheet to be stopped over a transport stop period, and this series of operations is included at least once or more during a reading period in which one document sheet is read.

Description

  The present invention relates to a technique for conveying a document sheet using a motor and reading the document sheet.

  2. Description of the Related Art Conventionally, a document reading apparatus that transports a document and reads the document being transported is known. These apparatuses include a conveyance roller that conveys the document, and conveys the document by rotating the conveyance roller using a motor.

  In such an apparatus having a function of conveying a document, a technique for managing the temperature of a motor that rotates a conveyance roller when conveying a document is known (for example, Patent Document 1). In this technique, the temperature of the motor is measured while a plurality of originals are being conveyed, and if the motor temperature reaches a predetermined upper limit temperature, the reading of the original is completed for the original being read, and Concerning the original, the conveyance of the original is stopped, and the conveyance of the original between the originals is stopped for a certain period. Then, the temperature of the motor is measured while the document conveyance is stopped, and the conveyance of the document is resumed if the temperature of the motor decreases during the next one document conveyance.

JP 2005-289626 A

  In the prior art, when a document is read at a high resolution or when a color image of a document is read, a single document is transported as compared to when reading a document at a low resolution or when reading a monochrome image of a document. The temperature rise during this period increases. That is, the temperature that must be lowered before the conveyance of the original is restarted increases, and the stop period for stopping the original conveyance during the conveyance of the original is prolonged. For this reason, there has been a problem that the user of the image reading apparatus misunderstands the stop of document conveyance during conveyance as the end of document conveyance. Further, there is a problem that the stop period exceeds the allowable connection time of an external device such as a PC connected to the image reading apparatus, and the external apparatus is erroneously detected that a communication error has occurred between the external apparatus and the image reading apparatus. It was happening. As described above, in an image reading apparatus that reads a document sheet that is a sheet-like document, reading of the document sheet is stopped during reading of the document sheet in order to suppress an increase in the temperature of the motor, and the stop period is prolonged. There was a problem to do.

  The present specification discloses a technique for shortening a stop period for stopping reading of a document sheet during reading of the document sheet in an image reading apparatus that reads the document sheet by moving the document sheet or the image reading unit using a motor. To do.

  An image reading device disclosed in the present specification includes an image reading unit that reads an image on a document sheet, a motor that includes a motor and moves the document sheet or the image reading unit, and a control unit. The control unit detects a temperature of the motor, and stops the movement by the transport unit when the temperature of the motor detected in the temperature detection process is equal to or higher than a reference temperature. An interruption process for resuming the movement of the transport unit when the temperature becomes lower than a reference temperature, an operation for the transport unit to rotate the motor for a first specified time, and an operation for stopping the rotation of the motor for a second specified time. A first conveyance instruction process for instructing the conveyance unit at least once during the reading of one original sheet by the image reading unit.

  In this image reading apparatus, when the temperature of the motor is lower than the reference temperature, the rotation of the motor is stopped at least once during reading of one original sheet. According to this image reading apparatus, the temperature rise of the motor in the operation of rotating the motor once is suppressed as compared with the case where the rotation of the motor is not stopped once during reading of one original sheet. Therefore, it is possible to reduce the temperature of the motor that has to be reduced to the second specified time for stopping the rotation of the motor, and to shorten the document sheet stop period.

  The image reading apparatus further includes a supply tray, the conveyance unit includes a conveyance roller that is rotated by the motor, and a document sheet placed on the supply tray is conveyed to the conveyance path by the conveyance roller. The image reading unit is positioned on the conveyance path, reads an image of the original sheet conveyed by the conveyance unit, and the control unit performs the first conveyance instruction process in the conveyance unit. Includes a first predetermined time required for conveying a distance shorter than the sheet length of the original sheet, an operation of rotating the motor, and a second predetermined time, an operation of stopping the rotation of the motor. The operation may be instructed to the conveyance unit at least once during the reading of the single original sheet by the image reading unit.

  In this image reading apparatus, when the temperature of the motor is lower than the reference temperature, the original sheet is conveyed while stopping the rotation of the motor at least once during reading of one original sheet. According to this image reading apparatus, compared with the case where the conveyance of the original sheet is not stopped once during the reading of one original sheet, the conveyance of the original sheet is stopped by the rotation of the motor from the start of the conveyance of the original sheet. Alternatively, an increase in the temperature of the motor in one transport, which means transport from the resumption of transport of the original sheet to the stop of transport of the original sheet again, is suppressed. Therefore, it is possible to reduce the temperature of the motor that has to be reduced to the second specified time for stopping the rotation of the motor, and to shorten the document sheet stop period.

  In the image reading apparatus, the control unit may further include a time required for the image reading unit to read one original sheet conveyed by the conveying unit according to the reading condition of the image reading unit. A reading condition determination process is executed to determine which reading condition is a first reading condition longer than a reference time or a second reading condition in which the time required is equal to or less than the reference time, and the reading condition determination process The first conveyance instruction process may be executed when it is determined that the first reading condition is satisfied.

  Since the time required to read one original sheet is longer in the first reading condition than in the second reading condition, the amount of heat generated by the motor during the reading of one original sheet is also larger than in the second reading condition. . According to this image reading apparatus, the document sheet stop period can be shortened under the first reading condition in which the motor generates a large amount of heat and the motor temperature is likely to rise.

  In the image reading apparatus, the control unit further reads the image of the document sheet except for the stop by the interruption process when the second reading condition is determined by the reading condition determination process. A second conveyance instruction process instructing the conveyance unit may be executed so as not to stop during reading by the unit.

  According to this image reading apparatus, in the second reading process, the conveyance of the conveying unit is not stopped during the reading of one original sheet except for the stop by the interruption process. Therefore, the original sheet can be read at a higher speed than the first reading process in which the rotation of the motor is stopped at least once during the reading of one original sheet.

  In the image reading apparatus, the first reading condition is a reading condition for reading the original sheet at high resolution or color reading, and the second reading condition is for reading the original sheet at low resolution. Alternatively, it may be configured as a reading condition for monochrome reading.

  According to this image reading apparatus, when the original sheet is read with high resolution or color reading, the stop period of the original sheet can be shortened.

  In the image reading apparatus, the conveyance path includes a curved portion having a radius of curvature equal to or less than a reference value, and the first specified time is shorter than the sheet length, and the curved path along the conveyance path The transport unit may be configured to have a time required to transport the document sheet by a distance longer than the length.

  In this image reading apparatus, the first specified time is set based on a distance shorter than the sheet length and longer than the length of the curved portion along the conveyance path. Since the distance is shorter than the sheet length, the trailing end portion of the original sheet in the conveyance direction does not reach the curved portion as a result of conveyance in the first specified time, and the stop time for stopping the rotation of the motor is reached. Maintaining a posture along the curved portion is suppressed. In addition, since the distance is longer than the length of the curved portion along the conveyance path, the rear end portion of the document sheet in the conveyance direction can pass through the curved portion by the next conveyance in the first specified time. It is suppressed that the posture along the curved portion is maintained during the stop time. According to this image reading apparatus, the trailing edge portion of the document sheet in the transport direction is suppressed from being maintained in a posture along the curved portion over the stop time for stopping the rotation of the motor, and the trailing edge of the document sheet is suppressed. It is possible to suppress the curling of the portion.

  The image reading apparatus may further include a connection unit connected to an external device, and the second specified time may be set to a time shorter than the allowable connection time of the external device.

  According to this image reading apparatus, the communication between the external apparatus and the image reading apparatus is performed in the external apparatus at the second specified time when the rotation of the motor is stopped during the conveyance of the original sheet and the reading of the original sheet is stopped accordingly. It is possible to suppress erroneous detection that an error has occurred.

  In the image reading apparatus, the image reading unit further includes a storage unit that stores image data generated by reading the document sheet, and the control unit includes the motor in the first conveyance instruction process. When the conveyance unit is instructed to alternately and repeatedly execute the operation of rotating the motor and the operation of stopping the rotation of the motor, and the writable area in the storage unit is equal to or larger than a reference capacity The operation of stopping the rotation of the motor may be terminated and the conveying unit may be instructed to execute the operation of rotating the motor.

  In this image reading apparatus, when the operation of stopping the rotation of the motor during conveyance of the original sheet is finished and the operation of rotating the motor is started, it is also determined whether or not the writable area in the storage unit exceeds the reference capacity. To do. Therefore, shortly after starting the operation of rotating the motor, it is possible to suppress a situation in which the writable area in the storage unit is insufficient and the rotation of the motor is stopped again.

  In the image reading apparatus disclosed in this specification, in an image reading apparatus that conveys a document sheet by using a motor and reads the document sheet, the stop period for stopping the document sheet conveyance during the document sheet conveyance is shortened. Can do.

Schematic sectional view of an image reading device Block diagram schematically showing the electrical configuration of the image reading apparatus The flowchart which shows the starting process of 1st Embodiment Flow chart showing ADF reading process Flow chart showing the reading process Flow chart showing memory full stop determination process Flow chart showing memory full restart determination process The figure explaining conveyance stop distance W in the 1st reading conditions Graph showing the relationship between the elapsed time and the motor temperature during document sheet conveyance The flowchart which shows the starting process of 2nd Embodiment Flow chart showing second ADF reading process

<Embodiment 1>
The first embodiment will be described with reference to FIGS.

1. FIG. 1 is a cross-sectional view of a multifunction machine 1 that is an example of an image reading apparatus according to the present embodiment. The multifunction device 1 is a multi-function peripheral device having a printer function, a scanner function, a copy function, a facsimile function, and the like.

  As shown in FIG. 1, the multi-function device 1 is configured by mounting a main unit 3 and a document transport unit 4 on the upper side in this order. The main unit 3 includes a first reading unit 21 and a first platen glass 25 and a second platen glass 27 made of a transparent glass plate on its upper surface, a pressing member 32, and the like. The first reading unit 21 is an example of an image reading unit.

  The document transport unit 4 covers the entire upper surface of the main unit 3 and is configured to be able to open and close the upper surface of the main unit 3. The document transport unit 4 includes a transport unit 48 having an automatic document feed function (ADF) for automatically transporting a document sheet along a transport path 47, and also includes a top cover 11 and the like.

  The upper surface cover 11 is provided on the upper surface of the document conveyance unit 4 and is configured to be openable and closable with respect to the document conveyance unit 4 around an axis provided near the right end thereof. When the top cover 11 is displaced to the open position, the opening 4B of the document transport unit 4 is opened. The upper surface cover 11 displaced to the open position constitutes the right portion of the document table 12 on which the document sheet is placed. As shown in FIG. 1, when the upper surface cover 11 is displaced to the closed position, the opening 4B is closed. The document table 12 is an example of a supply tray.

  As shown in FIG. 1, the document transport unit 4 further includes a second reading unit 22, a third platen glass 28 made of a transparent glass plate, a pressing member 31, a front sensor (hereinafter referred to as F sensor) 18, a rear sensor (hereinafter referred to as “sensor”). , R sensor) 19, and various rollers such as a suction roller 41, a supply roller 42, a first transport roller 43, and a second transport roller 44. The second reading unit 22 is another example of the image reading unit, and the various rollers are examples of a conveyance roller.

  In the document transport unit 4, a transport path 47, which is a path through which a document sheet is transported from the document table 12 to the opening 4 </ b> B by various rollers, is provided. Two reading units 22 are arranged.

  The first reading unit 21 is disposed in the main unit 3 and is formed so as to spread in the main scanning direction D1. Further, as indicated by an arrow 82 in FIG. 1, the first reading unit 21 is supported so as to be movable in the sub-scanning direction perpendicular to the main scanning direction D1, that is, in the left-right direction, on the lower side of the first platen glass 25. . The first reading unit 21 is placed stationary on the first platen glass 25 while moving in the left-right direction by a flat bed driving unit (hereinafter referred to as FB driving unit) 49 connected to a motor M2 (see FIG. 2). Read the original sheet. The first reading unit 21 stops at the reading position L <b> 1 below the second platen glass 27, and the original sheet conveyed in the conveyance direction D <b> 2 along the conveyance path 47 passes over the second platen glass 27. The image on the original sheet is read. A combination of the motor M2 and the FB drive unit 49 is an example of a transport unit.

  The pressing member 31 is arranged to face the second platen glass 27 and presses the original sheet against the second platen glass 27 so that the original sheet passing over the second platen glass 27 does not float from the second platen glass 27. To do. In the following description, unless otherwise specified, the state and operation of the first reading unit 21 stationary at the reading position L1 are described.

  The second reading unit 22 is supported so as not to move to the reading position L <b> 2 in the document transport unit 4. The second reading unit 22 reads the document sheet when the document sheet transported through the transport path 47 passes directly below the third platen glass 28. The pressing member 32 is disposed in the main body unit 3 so as to face the third platen glass 28, and the document sheet is moved to the third platen glass 28 so that the document sheet passing immediately below the third platen glass 28 does not float from the third platen glass 28. Press against the platen glass 28.

  The F sensor 18 is disposed on the document table 12 and detects whether or not a document sheet is placed on the document table 12. The R sensor 19 is disposed at a detection position L3 upstream of the reading positions L1 and L2 in the conveyance path 47, and is turned on when the document sheet passes the detection position L3 on the conveyance path 47, and the document sheet is detected at the detection position L3. Turns off when not passing through L3. That is, the R sensor 19 detects a document sheet that passes the detection position L3 on the transport path 47.

  Various rollers such as the suction roller 41, the supply roller 42, the first conveyance roller 43, and the second conveyance roller 44 are rotated by a motor M <b> 1 (see FIG. 2), and the document sheet placed on the document table 12 is conveyed in the conveyance path 47. Are conveyed to the opening 4B. That is, the various rollers form a conveyance unit 48 that conveys the original sheet placed on the platen 12 along the conveyance path 47 to the opening 4B. A combination of the motor M1 and the transport unit 48 is another example of the transport unit.

  As shown in FIG. 1, the conveyance path 47 is provided with a portion (hereinafter, a curved portion) X along the second conveyance roller 44 in a curved shape, and the other portion is provided in a linear shape. In the multifunction device 1 of the present embodiment, the curvature radius of the curved portion X is set to be equal to or less than a specified value in order to reduce the size of the apparatus. Hereinafter, the length of the curved portion X along the conveyance path 47 is referred to as a curved distance L.

  A biasing portion 17 is provided on the discharge path 15 side of the discharge tray 15. The urging portion 17 is configured in a shape in which a strip-like resin film having elasticity is folded in two. The urging unit 17 urges the position on the front end side by a reference distance LK from the rear end of the document sheet discharged onto the discharge tray 15, and thereby, as shown in an enlarged view in FIG. 1. The trailing edge of the document sheet discharged onto the discharge tray 15 warps upward along the urging portion 17.

  Accordingly, the original sheet conveyed later along the conveyance path 47 is the original sheet conveyed first, and is urged with the original sheet whose rear end is warped upward as a result of being sent to the discharge tray 15. It is sent out between the parts 17, that is, under the original sheet conveyed first. As a result, a plurality of document sheets placed in order from the lower side with one side facing down on the document table 12 are sequentially turned from the upper side with one side facing up on the discharge tray 15. Placed on.

  Furthermore, the multifunction device 1 includes a power switch and various setting buttons, an operation unit 7 (see FIG. 2) that receives an operation command from the user, and a display that displays the status of the multifunction device 1 including an LED and a liquid crystal display. A unit 9 (refer to FIG. 2) and a USB interface (hereinafter referred to as USB I / F) 8 connected to an external computer (hereinafter referred to as external PC) or the like via a communication line such as a USB cable are provided. The USB I / F 8 is an example of a connection unit.

2. As shown in FIG. 2, the multifunction device 1 includes a central processing unit (hereinafter referred to as CPU) 70, ROM 76, RAM 77, device control unit 73, first analog front end (hereinafter referred to as AFE) 74, A 2AFE 75 and a drive circuit 78 are provided, and an operation unit 7, a display unit 9, a USB I / F 8, and various sensors 18 and 19 are connected to these via a bus 80. As indicated by a dotted line 71 in FIG. 10, the one including the CPU 70 and the ROM 76 is an example of a control unit, and the RAM 77 is an example of a storage unit.

  Various programs for controlling the operation of the multifunction device 1 are stored in the ROM 76, and the CPU 70 controls each unit in accordance with the program read from the ROM 76 and executes a reading process to be described later. Further, the ROM 26 stores a conveyance stop distance, a conveyance stop period, a reference temperature YK, a restart reference temperature YS, a reference capacity, and the like, which will be described later.

  The device control unit 73 is connected to the reading units 21 and 22, and transmits a reading control signal to the reading units 21 and 22 based on a command from the CPU 70. The reading unit 21 reads one side of the document sheet based on a reading control signal from the device control unit 73, and the reading unit 22 reads the other side of the document sheet based on a reading control signal from the device control unit 73. read.

  When reading the original sheet conveyed along the conveyance path 47, the reading units 21 and 22 repeat reading a plurality of times in the main scanning direction D1 at the reading positions L1 and L2. The reading units 21 and 22 generate unit reading data by one reading in the main scanning direction D1. The reading units 21 and 22 repeat reading in the main scanning direction D1, thereby generating read data composed of a plurality of unit read data in the sub-scanning direction, and outputting the acquired read data to the AFEs 74 and 75. .

  The first AFE 74 is connected to the first reading unit 21, and converts the analog signal read data output from the first reading unit 21 into a digital signal, that is, gradation data read data, based on a command from the CPU 70. To do. The first AFE 74 stores the converted read data in the RAM 77 via the bus 80. The second AFE 75 is connected to the second reading unit 22 and converts the read data of the analog signal output from the second reading unit 22 into the read data of the gradation data based on a command from the CPU 70. The second AFE 75 stores the converted read data in the RAM 77 via the bus 80. The read data is an example of image data.

  The drive circuit 78 is connected to each of the motors M1 and M2 (hereinafter, generically M), and rotates the motor M based on a pulse signal input from the CPU. The motor M is driven to rotate by one rotation angle with one pulse of the pulse signal. When the motor M1 is driven by one step, the various rollers constituting the conveyance unit 48 rotate by a predetermined angle, and the original sheet is conveyed on the conveyance path 47 by the first specified distance. When the CPU 70 conveys and reads the document sheet, the CPU 70 transmits a pulse signal having a first specified period to the drive circuit 78, and accordingly, the conveying unit 48 multiplies the number of pulses of the pulse signal by the first specified distance. The original sheet is conveyed by a distance.

  When the motor M2 is driven by one step, the FB drive unit 49 moves the first reading unit 21 by the second specified distance. When the CPU 70 reads a document sheet placed stationary on the first platen glass 25, the CPU 70 transmits a pulse signal having a second specified cycle to the FB drive unit 49, and the FB drive unit 49 accordingly transmits the pulse signal. The first reading unit 21 is transported by a distance obtained by multiplying the number of signal pulses by the second specified distance. Hereinafter, the number of pulses of the pulse signal transmitted from the CPU 70 to the motor M is referred to as a step number SN.

3. Motor temperature detection The temperature of the motor M rises with the input of a pulse signal, that is, with rotation. If the temperature rises excessively, the motor M may be damaged. Therefore, the CPU 70 detects the temperature Y of the motor M when reading the document sheet, and temporarily stops the rotation of the motor M when detecting that the temperature Y of the motor M has become equal to or higher than the reference temperature YK. Thus, the reading of the original sheet is performed in the middle. Then, the CPU 70 rotates the motor M when the temperature Y of the motor M falls below the restart reference temperature YS, and resumes reading of the original sheet. The reference temperature YK and the restart reference temperature YS are examples of the reference temperature.

  The temperature Y of the motor M can be detected by various methods. For example, the temperature Y may be detected using a contact-type or non-contact-type temperature sensor, or may be detected by estimating the temperature Y using a calculation formula. In the present embodiment, an example in which the temperature of the motor M is detected by estimation using a calculation formula will be described.

The temperature Y of the motor M rises in proportion to the step number SN of the pulse signal input to the drive circuit 78 from when the multifunction device 1 is turned on, and from when the multifunction device 1 is turned on. It descends in proportion to the elapsed time T. Therefore, the temperature Y of the motor M is estimated as follows using the coefficients A and B.
Temperature Y = A × number of steps SN−B × elapsed time T

  Here, A is a heating coefficient determined according to the rotational speed of the motor M. The step number SN is counted for each rotation speed, and the total value of products obtained by multiplying the number of pulses for each rotation speed by the heating coefficient A corresponding to the rotation speed is used as “A × step number SN”. B is a heat dissipation coefficient.

4). Reading Process Next, an original sheet reading process will be described with reference to FIGS. In the present embodiment, after the multifunction device 1 is turned on, the document sheet placed on the document table 12 is automatically moved along the conveyance path 47 using the conveyance unit 48 based on an instruction from the user. A process when the so-called ADF reading is performed in which the original sheet is read while being conveyed will be described.

(Start process)
As shown in FIG. 3, when the power is turned on to the multifunction device 1 by the user, the CPU 70 starts a startup process, and the pulse signal input to the drive circuit 78 after the power to the multifunction device 1 is turned on. The number of steps SN is counted, the elapsed time T from when the multifunction device 1 is turned on is counted, and a temperature detection process for detecting the temperature Y of the motor M1 from the above-described calculation formula is executed (S2). Thereafter, the CPU 70 detects the temperature Y of the motor M1 at regular time intervals while the power of the multi-function device 1 is turned on.

  The CPU 70 waits for a reading instruction to be input from the user via the operation unit 7 (S4: NO). When it is confirmed that the document sheet is placed on the document table 12 using the F sensor 18 and a reading instruction is input from the user (S4: YES), the CPU 70 receives the reading instruction together with the reading instruction. Reading conditions such as the reading surface of the original sheet, resolution, and color / monochrome settings are acquired (S6).

  In the present embodiment, as described above, ADF reading is set under the reading conditions. When confirming that ADF reading is set in the reading conditions, the CPU 70 executes ADF reading processing (S8).

(ADF reading process)
As shown in FIG. 4, in the ADF reading process, the CPU 70 first checks the reading conditions (S12). The CPU 70 checks whether the resolution of the reading condition is a resolution higher than the reference resolution of 600 dpi, for example, a high resolution setting of 2400 dpi, or a resolution lower than the reference resolution, for example, a low resolution setting of 600 dpi. Further, the CPU 70 determines that the color / monochrome setting of the reading condition is a color setting for reading an original sheet as a plurality of read data for a plurality of color components, or a single reading for an original sheet for one color component. Check if the monochrome setting is read as data.

  When the reading condition is the high resolution setting or the color setting, the number of unit reading data read by the reading units 21 and 22 is large, and the reading time necessary for reading one original sheet is too long. Longer than the reference time set according to the document size. On the other hand, when the reading condition is a low resolution setting or a monochrome setting, the number of unit reading data read by the reading units 21 and 22 is small, and the reading time required for reading one original sheet is small. Less than the reference time.

  In other words, when the high resolution setting or color setting is set in the scanning conditions, the scanning time is longer than the reference time, and when the low resolution setting or monochrome setting is set, the scanning time is the reference. Less than time. Hereinafter, in the reading conditions, a condition in which at least one of the high resolution setting and the color setting is set is referred to as a first reading condition, and a condition in which the low resolution setting and / or the monochrome setting is set is referred to as a second reading condition. Called. Here, in the second reading condition, the condition that the low resolution setting or the monochrome setting is included includes that the resolution and the color / monochrome setting are not always set in the reading instruction. This is for defining the second reading condition when only one of them is set.

  The CPU 70 confirms the reading condition and determines whether the reading condition is the first reading condition or the second reading condition. In the case of the first reading condition (S12: YES), the CPU 70 sets the transport stop distance to the distance W (mm) (see FIG. 8), and sets the transport stop period (see FIG. 9) to 30 (seconds). Here, the conveyance stop distance means a stop interval for periodically stopping the conveyance of the document sheet during the conveyance of the document sheet, and the conveyance stop period means a stop period in one conveyance stop. The conveyance stop period is an example of a second specified time.

  As shown in FIG. 9, when the temperature Y of the motor M1 is lower than the reference temperature YK, the CPU 70 instructs the conveyance unit 48 to convey the original sheet. In the first reading condition, the CPU 70 shows a solid line in FIG. Thus, every time the document sheet is transported by the transport stop distance, an instruction is given to stop the transport of the document sheet over the transport stop period. That is, when instructing the conveyance of the document sheet, the CPU 70 transmits a pulse signal of a corresponding number of steps SN necessary to convey the document sheet by the conveyance stop distance to the drive circuit 78 to rotate the motor M1. And the stop operation | movement which stops transmission of a pulse signal and stops the motor M1 over a conveyance stop period is repeated alternately. Therefore, in the case of the first reading condition, the temperature Y of the motor M1 increases during the transport operation and decreases during the stop operation. The time required to transmit a pulse signal having a corresponding number of steps SN is an example of a first specified time.

  As shown in FIG. 8, the conveyance stop distance W in the first reading condition is set to be shorter than the sheet length Z of the original sheet in the conveyance direction D2 and longer than the bending distance L. Accordingly, when the first reading condition is satisfied, the CPU 70 conveys the original sheet using the conveying unit 48 and reads an original sheet image using the reading units 21 and 22. During the period, the transfer operation and the stop operation are executed at least once. That is, the stop operation for stopping the motor M1 is included once or more during the reading period of one original sheet.

  In the present embodiment, the sheet length Z is longer than twice the bending distance L, and the conveyance stop distance W is set to a half length of the sheet length Z. Therefore, in the case of the first reading condition, one original sheet is conveyed by two conveyance operations, and one stop operation is included between the two conveyance operations. In the present embodiment, the difference distance LM obtained by subtracting the bending distance L from the conveyance stop distance W is set to be longer than the reference distance LK shown in FIG.

  Note that the conveyance stop period in the first reading condition is set to a time shorter than the allowable connection time of the external PC connected via the USB I / F 8. Here, the allowable connection time refers to the time when the external PC has a communication interruption period during which communication is not performed during communication with the external PC, such as when the read data read by the multifunction device 1 is transmitted to the external PC. The communication interruption period is a known interruption value, which is a reference interruption period when determining the communication error as a communication error. Since the conveyance stop period is set to a time shorter than the allowable connection time, even if a stop operation is included in the reading period of one original sheet, the communication interruption period accompanying the stop operation is determined as a communication error. It is avoided.

  On the other hand, in the case of the second reading condition (S12: NO), the CPU 70 sets the conveyance stop distance to 0 (mm) and sets the conveyance stop period to 0 (seconds). That is, in the case of the second reading condition, when the temperature Y of the motor M1 is lower than the reference temperature YK, an instruction is given so as not to stop the conveyance of the document sheet during the conveyance of the document sheet (see the one-dot chain line in FIG. 9). Accordingly, in the second reading condition, the conveyance of the original sheet is not stopped during the reading period of one original sheet, except when the temperature Y of the motor M1 becomes equal to or higher than the reference temperature YK. The temperature Y rises continuously.

  When the CPU 70 sets the conveyance stop distance and the conveyance stop period, the CPU 70 instructs the conveyance unit 48 to convey the original sheet based on the set conveyance stop distance and conveyance stop period (S18), and executes the reading process (S20). . The process of instructing conveyance based on the setting of S14 is an example of the first conveyance instruction process, and the process of instructing conveyance based on the setting of S16 is an example of the second conveyance instruction process.

(Reading process)
The CPU 70 executes a reading process for each original sheet conveyed using the conveyance unit 48. As shown in FIG. 5, in the reading process, the CPU 70 resets the stop determination counter and the restart determination counter that increase as the number of steps SN increases, and the R sensor 19 turns on as the document sheet conveyance starts. (S42: NO). When the R sensor 19 is turned on (S42: YES), the CPU 70 further conveys the original sheet by the first step number SN1 corresponding to the distance between the detection position L3 and the reading positions L1 and L2 along the conveyance path 47, and Based on the acquired reading setting, the reading units 21 and 22 are instructed to read the original sheet (S44). When starting to read the original sheet, the CPU 70 executes a memory full stop determination process (S46).

  In the reading process, the CPU 70 executes the processes from S46 to S62 including the memory full stop determination process every time the document sheet is conveyed by the first specified distance corresponding to one step. That is, when reading of the original sheet is started, the CPU 70 conveys the original sheet by the first specified distance every time the step number SN increases by 1, and reads the original sheet by the reading units 21 and 22 to generate unit read data. At the same time, the processing from S46 to S62 is executed. In the processing from S46 to S62, every time the step number SN increases by 1, the counter increases by 1.

(Memory full stop judgment process)
The memory full stop determination process will be described with reference to FIG. In the memory full stop determination process, whether or not to stop the conveyance of the original sheet is indicated based on the set conveyance stop distance and whether or not the RAM 77 has a writable area in which read data or the like can be stored. Set the stop flag.

  In the memory full stop determination process, the CPU 70 first sets the stop flag to OFF (S72), and checks whether there is a writable area in the RAM 77 (S74). When there is no writable area in the RAM 77 (S74: NO), the CPU 70 sets the stop flag to ON (S76). On the other hand, when there is a writable area in the RAM 77 (S74: YES), the CPU 70 keeps the stop flag off.

  Next, the CPU 70 confirms the setting of the conveyance stop distance (S78). If the conveyance stop distance is set to 0 (mm) (S78: YES), that is, if the reading setting is the second reading setting, The memory full stop determination process ends. On the other hand, when the conveyance stop distance is set to the distance W (mm) (S78: NO), that is, when the reading setting is the first reading setting, the CPU 70 increments the conveyance determination counter by 1 (S80).

  Next, the CPU 70 calculates the conveyance determination distance by multiplying the conveyance determination counter and the first specified distance corresponding to one step, and compares the conveyance determination distance with the conveyance stop distance (S82). When the conveyance determination distance is less than the conveyance stop distance (S82: NO), the CPU 70 ends the memory full stop determination process. On the other hand, when the conveyance determination distance is equal to or greater than the conveyance stop distance (S82: YES), the CPU 70 sets the stop flag to ON (S84). The CPU 70 resets the conveyance determination counter (S86), and ends the memory full stop determination process.

  When the CPU 70 completes the memory full stop determination process, the CPU 70 returns to the reading process shown in FIG. 5 and checks the stop flag (S48). When the stop flag is set to ON (S48: YES), the CPU 70 instructs the conveyance unit 48 to stop conveying the original sheet (S54). Further, the CPU 70 instructs the reading units 21 and 22 to stop reading the original sheet (S56), and executes a memory full restart determination process (S58).

(Memory full restart judgment process)
The memory full restart determination process will be described with reference to FIG. In the memory full resumption determination process, a resumption flag indicating whether or not to resume the conveyance of the original sheet is set based on the set conveyance stop time and whether or not the writable area in the RAM 77 exceeds the reference capacity. To do. Here, the reference capacity means a capacity necessary for resuming reading of a manuscript sheet accompanying resumption of manuscript sheet conveyance, and specifically, unit reading for each of the reading units 21 and 22 used for reading the manuscript sheet. It means a capacity that can store about 10 pieces of data.

  In the memory full restart determination process, the CPU 70 first sets the restart flag to OFF (S92), and checks whether or not the writable area exceeds the reference capacity in the RAM 77 (S94). If there is more than the reference capacity in the RAM 77 (S94: YES), the CPU 70 sets the resume flag to ON (S96). On the other hand, when there is no writable area or more in the RAM 77 in the RAM 77 (S94: NO), the CPU 70 keeps the restart flag off.

  Next, the CPU 70 confirms the setting of the conveyance stop period (S98), and when the conveyance stop distance is set to 0 (second) (S98: YES), that is, when the reading setting is the second reading setting, The restart determination flag is set to ON (S100). On the other hand, when the conveyance stop distance is set to 30 (seconds) (S98: NO), that is, when the reading setting is the first reading setting, the CPU 70 sets the restart determination flag to ON (S102).

  The CPU 70 calculates a restart determination period by multiplying the restart determination counter by a first predetermined period corresponding to one step, and compares the restart determination period with the conveyance stop period (S104). When the restart determination period is less than the conveyance stop period (S104: NO), the CPU 70 increments the restart determination counter by 1 (S80). On the other hand, if the restart determination period is equal to or longer than the conveyance stop period (S104: YES), the CPU 70 sets the restart determination flag to ON (S108).

  Next, the CPU 70 confirms the restart flag and the restart determination flag (S110). When either one of the flags is set to OFF (S110: NO), the CPU 70 sets the restart flag to OFF and ends the memory full restart determination process. On the other hand, when both flags are set to ON (S110: YES), the CPU 70 resets the restart determination counter (S114), and ends the memory full restart determination process.

  When the CPU 70 completes the memory full restart determination process, the CPU 70 returns to the reading process shown in FIG. 5 and checks the restart flag (S60). When the restart flag is set to OFF (S60: NO), the CPU 70 repeats the processing from S58. On the other hand, when the resumption flag is set to ON (S60: YES), the CPU 70 instructs the conveyance unit 48 to resume conveyance of the original sheet (S62), and causes the reading units 21 and 22 to resume reading the original sheet. Instructed (S64), the processing from S46 is repeated.

  On the other hand, when the stop flag is set to OFF (S48: NO), the CPU 70 checks the state of the R sensor 19. When the R sensor 19 is turned on or when the R sensor 19 is turned off, the CPU 70 does not convey the original sheet by the first step number SN1 after the R sensor 19 is turned off (S50). : NO), the process from S46 is repeated. On the other hand, when the R sensor 19 is turned off and the original sheet is conveyed by the first step number after the R sensor 19 is turned off (S50: YES), the CPU 70 transfers the original sheet to the reading units 21 and 22. The end of reading is instructed (S52), and the reading process ends.

  When the CPU 70 completes the reading process, the CPU 70 returns to the reading process shown in FIG. 4 and checks the state of the F sensor 19 (S22). When the F sensor 19 is on (S22: YES), that is, when the document sheet remains on the document table 12, the CPU 70 uses the temperature Y of the motor M1 detected by the temperature detection process as the reference temperature YK. (S24).

  When the CPU 70 detects that the temperature Y of the motor M1 is lower than the reference temperature YK (S24: NO), the CPU 70 repeats the processing from S20 on the next document sheet. On the other hand, when the CPU 70 detects that the temperature Y of the motor M1 is equal to or higher than the reference temperature YK (S24: YES), it corresponds to the distance between the reading positions L1, L2 and the discharge tray 15 along the transport path 47. The original sheet is further conveyed by the second step number SN2, and the original sheet on which the read data is read is discharged to the discharge tray 15. Then, the CPU 70 instructs the conveyance unit 48 to stop the conveyance of the document sheet (S26), and temporarily halts, that is, interrupts the conveyance of the document sheet.

  The CPU 70 waits for the temperature Y of the motor M1 to become lower than the restart reference temperature YS lower than the reference temperature YK (S28: NO), and when the temperature Y of the motor M1 becomes lower than the restart reference temperature YS (S28). : YES), the process from S18 is repeated. For example, in the case of the second reading condition, when the temperature Y of the motor M1 becomes lower than the reference temperature YK, the processing from S18 is repeated and the conveyance of the original sheet is started. Temperature Y exceeds the upper limit temperature YM of the motor M1, and the motor M1 fails.

  Therefore, in the present embodiment, a safety range ΔY that is a temperature difference larger than the temperature rise of the motor M1 during execution of the reading process in the case of the second reading condition is set, and the temperature Y of the motor M1 is higher than the upper limit temperature YM. When the temperature becomes lower than the restart reference temperature YS that is lower by the safety range ΔY, the processing from S18 is repeated. This suppresses the temperature Y of the motor M1 from exceeding the upper limit temperature YM of the motor M1 during the reading process.

  On the other hand, when the F sensor 19 is on (S22: YES), that is, when no document sheet remains on the document table 12, the CPU 70 further conveys the document sheet by the second step number SN2, and conveys the conveyance unit 48. Is instructed to end conveyance of the original sheet (S30), and the ADF reading process is terminated.

5. Advantages of the present embodiment (1) In the multifunction device 1 of the present embodiment, when the reading condition is the first reading condition and the temperature Y of the motor M1 is lower than the reference temperature YK, The rotation of the motor M1 is stopped once during the reading for the conveyance stop period, and the conveyance of the original sheet is stopped. As indicated by a solid line in FIG. 9, in the conveyance stop period, the rotation of the motor M1 is stopped, so the temperature Y of the motor M1 decreases. Therefore, the temperature increase of the motor M1 can be suppressed as compared with the case where the reading condition indicated by the alternate long and short dash line in FIG. 9 is the second reading condition.

(2) Further, the conveyance stop period can be set shorter than the interruption period ΔT in which the conveyance of the original sheet is temporarily stopped when the temperature Y of the motor M1 becomes equal to or higher than the reference temperature YK. Since the suspension period ΔT is a period during which the temperature Y of the motor M1 decreases to the restart reference temperature YS, the value cannot be set. On the other hand, the conveyance stop period has no such limitation and can be set shorter than the interruption period ΔT.

(3) Moreover, the conveyance stop period should just suppress the temperature rise of the motor M1 by the conveyance operation performed just before the stop operation | movement which concerns on the said conveyance stop period. Since the conveyance stop distance in which the original sheet is conveyed by one conveyance operation is set to be shorter than the sheet length Z of the original sheet, the temperature rise of the motor M1 due to the conveyance operation is in the case of the second reading condition. Thus, the temperature rise of the motor M1 when the entire original sheet is conveyed without being stopped is small. Therefore, the conveyance stop period can be set short, and the period during which the conveyance of the original sheet is stopped can be shortened.

(4) Furthermore, in the multifunction device 1 of the present embodiment, since the temperature rise of the motor M1 is suppressed, the number of occurrences of an event in which the temperature Y of the motor M1 becomes equal to or higher than the reference temperature YK can also be suppressed. Therefore, the number of times of stopping the conveyance of the original sheet over the interruption period ΔT longer than the conveyance stop period is suppressed, and the period during which the conveyance of the original sheet is stopped can be shortened.

(5) In the multifunction device 1 of the present embodiment, the conveyance of the original sheet is stopped once during the reading of one original sheet under the first reading condition in which the reading time is longer than the second reading condition. Since the reading time is longer in the first reading condition than in the second reading condition, the amount of heat generated by the motor M1 during reading one original sheet is also larger than that in the second reading condition. In the multi-function device 1, under the first reading condition where the amount of heat generated by the motor M1 is large and the temperature Y of the motor M1 is likely to rise, the temperature rise of the motor M1 is suppressed and the period during which the document sheet conveyance is stopped is shortened. Can do.

(6) Further, in the multi-function device 1 of the present embodiment, when the reading condition is the second reading condition and the temperature Y of the motor M1 is lower than the reference temperature YK, during reading of one original sheet. Do not stop the conveyance of the original sheet. Therefore, as indicated by a one-dot chain line in FIG. 9, the number of original sheets to be read is 1 to 3, and the interruption period ΔT does not occur even if the rotation of the motor M1 is not stopped during the reading of one original sheet. In this case, the original sheet can be read at a higher speed than when the reading condition indicated by the solid line in FIG. 9 is the first reading condition.

(7) In the MFP 1 of the present embodiment, as shown in FIG. 8, the conveyance stop distance W when the reading condition is the first reading condition is shorter than the sheet length Z of the original sheet and is along the conveyance path 47. The distance is set longer than the bending distance L which is the length of the bending portion X. Since the conveyance stop distance W is shorter than the sheet length Z, the rear end portion of the original sheet in the conveyance direction D2 does not reach the curved portion X as a result of the first conveyance operation. Is maintained in a posture along the curved portion X over the conveyance stop period. Further, since the conveyance stop distance W is longer than the bending distance L, the trailing end portion of the original sheet can pass through the curved portion X by the conveyance by the second conveyance operation, and the conveyance stop immediately after the second conveyance operation is performed. It is suppressed that the rear end portion of the document sheet is maintained in a posture along the curved portion X during the period. According to the multi function device 1, the trailing edge portion of the document sheet is prevented from being maintained in a posture along the curved portion X over the conveyance stop period, and the curling of the document sheet is curled downward. Can be suppressed.

(8) For example, when the trailing end portion of the document sheet is curled downward and the trailing end portion of the document sheet is curved along the curved portion X, the document sheet discharged onto the discharge tray 15 is moved upward. Even if the original sheet is urged, the rear end of the original sheet does not warp upward, and the original sheet conveyed later along the conveyance path 47 is the original sheet conveyed first, and the discharge tray 15 It is not possible to dive into the lower side of the document sheet sent to the printer.

(9) In the multi-function device 1 of the present embodiment, it is possible to prevent the curl of the original sheet from being curled downward. In particular, the difference distance LM obtained by subtracting the bending distance L from the conveyance stop distance W is set to be longer than the reference distance LK, and the curl is curled downward in the range of the reference distance LK from the rear end of the original sheet. Is suppressed. Therefore, a plurality of document sheets placed in order from the bottom side with one side facing down on the document table 12 are sequentially ordered from the top side with one side facing up on the discharge tray 15. It can be mounted reliably.

(10) In the MFP 1 according to the present embodiment, when the reading condition is the first reading condition, when shifting from the stop operation related to the transfer stop period to the transfer operation executed thereafter, The memory full restart determination process is executed, and in the memory full restart determination process, it is determined whether or not the writable area in the RAM 77 exceeds the reference capacity. For this reason, it is possible to prevent a situation in which the writable area is insufficient in the RAM 77 shortly after starting the transport operation and a situation in which the rotation of the motor M1 is stopped.

<Embodiment 2>
A second embodiment will be described with reference to FIGS. This embodiment is different from Embodiment 1 in that there are two types of ADF settings. In the following description, the same description as that of the first embodiment will not be repeated.

1. Reading Process As shown in FIG. 10, when a reading instruction is input from the user (S4: YES), the CPU 70 acquires reading conditions (S6). In the present embodiment, ADF reading is set as the reading condition, and further, either the first ADF reading or the second ADF reading is set. The CPU 70 confirms which ADF reading is set in the reading conditions (S122), and confirms that the first ADF reading is set (122: YES), executes the first ADF reading process (S124). . The first ADF reading process is the same as the ADF reading process of the first embodiment, and a duplicate description is omitted. On the other hand, when confirming that the second ADF reading is set (122: NO), the CPU 70 executes the second ADF reading process (S126).

(Second ADF reading process)
As shown in FIG. 11, in the second ADF reading process, the CPU 70 first sets the conveyance stop distance to 0 (mm) and sets the conveyance stop period to 0 (seconds) regardless of the reading conditions (S132). ), S134 to S140 are executed in the same manner as S18 to S24 of the first embodiment.

  When the CPU 70 detects that the temperature Y of the motor M1 detected immediately after the reading process (S136) is equal to or higher than the reference temperature YK (S140: NO), the CPU 70 checks the reading conditions (S142). In the case of the first reading condition (S142: YES), the CPU 70 resets the transport stop distance to the distance W (mm), resets the transport stop period to 30 (seconds), and performs steps S26 and S28 of the first embodiment. Similarly, the processes of S134 to S140 are executed. On the other hand, in the case of the first reading condition (S142: YES), the CPU 70 maintains the conveyance stop distance and the conveyance stop period at the currently set values, and executes the processes of S134 to S140.

2. Advantages of the present embodiment (1) In the multifunction device 1 of the present embodiment, when the second ADF reading is set, first, the original sheet is read without stopping the conveyance of the original sheet, and the motor M1 When the temperature Y is equal to or higher than the reference temperature YK, it is reset whether or not the conveyance of the original sheet is stopped during the reading of one original sheet according to the reading condition. Then, when the original sheet is stopped while reading one original sheet by resetting, the original sheet is conveyed by repeating the conveying operation and the stopping operation as indicated by the dotted line in FIG.

(2) According to the multifunction device 1 of the present embodiment, when the second ADF reading is set, the original sheet is read without stopping the conveyance of the original sheet. If the interruption period ΔT does not occur even if the rotation of the motor M1 is not stopped during the reading of one original sheet, the original sheet can be read at high speed.

(3) When the temperature Y of the motor M1 becomes equal to or higher than the reference temperature YK, that is, when the number of original sheets to be read is four or more, the original sheet is read while one original sheet is being read. Since whether or not to stop the conveyance is reset, the original sheet can be conveyed according to the reading conditions.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and the drawings, and for example, the following various aspects are also included in the technical scope of the present invention.
(1) In the above embodiment, the description has been given by using the multi-function device 1 having a printer function, a scanner function, a copy function, a facsimile function, etc., but the present invention is not limited to this, and an image having at least a scanner function. It may be a reading device.

(2) In the above-described embodiment, the multifunction device 1 has one CPU 70, and an example in which various processes such as a conveyance reading process are executed by the one CPU 70 has been described. Not limited. For example, if each unit may be configured by a plurality of CPUs, each unit may be configured only by a hardware circuit such as an ASIC (Application Specific Integrated Circuit). Furthermore, each part may be comprised by one or several CPU and ASIC.

(3) Further, the program executed by the CPU 70 does not necessarily have to be stored in the ROM 76, and may be stored in the CPU 70 itself or in another storage device.

(4) Although the above embodiment has been described using an example in which ADF reading is performed using the transport unit 48, the present invention is not limited to this. The present invention may be applied when so-called FB reading is performed in which an original sheet placed stationary on the first platen glass 25 is read while moving the first reading unit 21 using the FB driving unit 49.

(5) In the above embodiment, the description has been given using the example of checking the writable area of the RAM 77 in the memory full stop determination process and the memory full restart determination process, but the present invention is not limited to this. When the writable area of the RAM 77 is managed by a separate process, it is not always necessary to check the writable area.

(6) Although the above embodiment has been described using an example in which the conveyance stop distance W in the first reading condition is set to half the sheet length Z, the present invention is not limited to this. The conveyance stop distance W can be set to an arbitrary distance shorter than the sheet length Z of the original sheet in the conveyance direction D2 and longer than the bending distance L.

(7) In the above embodiment, the description has been made using the example in which whether or not the conveyance of the original sheet is stopped during the reading of one original sheet is set according to the reading condition. However, the present invention is not limited to this. I can't. Regardless of the reading conditions, it may be set so that the conveyance of the original sheet is stopped during the reading of one original sheet.

(8) The document sheet is set to be stopped during reading of one document sheet, and can be placed on the document table 12 at once by adjusting the transport stop distance and the transport stop period. The number of document sheets can be set so that the temperature Y of the motor M1 does not rise to the reference temperature YK. In such a case, detection of the temperature Y of the motor M1 itself is not always necessary.

3: body unit, 4: document transport unit, 17: biasing unit, 47: transport path, 48: transport unit, 49: FB drive unit, 78: drive circuit, L: bending distance, L1, L2: reading position, L3: detection position, LK: reference distance, T: elapsed time, W: conveyance stop distance, X: curved portion, Y: temperature, YK: reference temperature, YS: restart reference temperature, Z: sheet length, ΔT: interruption period , ΔY: Safety range

Claims (8)

An image reading unit for reading an image of an original sheet;
A transport unit that includes a motor and moves the document sheet or the image reading unit;
A control unit;
With
The controller is
Temperature detection processing for detecting the temperature of the motor;
When the temperature of the motor detected in the temperature detection process becomes equal to or higher than a reference temperature, the interruption process is stopped so that the movement by the conveyance unit is stopped and the movement of the conveyance unit is resumed when the temperature becomes lower than the reference temperature. When,
A series of operations including the operation of rotating the motor for the first specified time and the operation of stopping the rotation of the motor for the first specified time by the conveying unit are performed by the image reading unit for one original sheet. A first transport instruction process for instructing the transport unit at least once during reading;
An image reading apparatus that executes The image reading apparatus according to claim 1,
Furthermore,
With a supply tray,
The transport unit is
A conveyance roller that is rotated by the motor, and conveys a document sheet placed on the supply tray along the conveyance path by the conveyance roller;
The image reading unit
Read the image of the original sheet that is located on the transport path and transported by the transport unit,
The controller is
The first conveying instruction process includes the operation of rotating the motor for the first specified time required for the conveying unit to convey a distance shorter than the length of the original sheet, the second specified time, and the motor. A series of operations including an operation of stopping the rotation of the document sheet is instructed to the transport unit at least once during the reading of the one original sheet by the image reading unit.
Image reading device. The image reading apparatus according to claim 2,
The controller is
Furthermore,
The reading condition of the image reading unit is a first reading condition in which the time required for the image reading unit to read one original sheet conveyed by the conveying unit is longer than a reference time, or the time required for the image reading unit Executing a reading condition determination process for determining which of the second reading conditions is equal to or less than the reference time,
Executing the first conveyance instruction process when the first reading condition is determined by the reading condition determination process;
Image reading device. The image reading apparatus according to claim 3,
The controller is
Furthermore,
When the second reading condition is determined by the reading condition determination process, the conveyance unit is configured not to stop the document sheet during reading by the image reading unit except for the stop by the interruption process. Execute a second conveyance instruction process to instruct;
Image reading device. The image reading apparatus according to claim 3 or 4, wherein:
The first reading condition is a reading condition for reading the original sheet at high resolution or color reading.
The second reading condition is a reading condition for reading the original sheet at a low resolution or monochrome reading.
Image reading device. An image reading apparatus according to any one of claims 2 to 5,
The conveyance path has a curved portion with a radius of curvature equal to or less than a reference value,
The first specified time is a time required for the transport unit to transport the document sheet by a distance shorter than the sheet length and longer than the length of the curved portion along the transport path.
Image reading device. An image reading apparatus according to any one of claims 1 to 5,
Furthermore,
It has a connection part that is connected to an external device,
The second specified time is set to a time shorter than the allowable connection time of the external device.
Image reading device. The image reading apparatus according to any one of claims 1 to 6,
Furthermore,
The image reading unit includes a storage unit that stores image data generated by reading the document sheet,
The controller is
In the first conveying instruction process, the conveying unit is instructed to alternately and repeatedly execute an operation of rotating the motor and an operation of stopping the rotation of the motor, and writing in the storage unit Instructing the transport unit to perform an operation of rotating the motor by stopping the operation of stopping the rotation of the motor when the possible area is equal to or larger than a reference capacity;
Image reading device.

Images