JP6265739B2 - Conveying device and motor temperature prediction method - Google Patents

Description

  The present invention relates to a conveying device that conveys a sheet using a motor as a drive source, an image reading device that reads an image recorded on a sheet conveyed by the conveying device, a recording device that records an image on a sheet conveyed by the conveying device, and The present invention relates to a motor temperature prediction method.

  In Patent Document 1, in a conveying apparatus that conveys a sheet using a motor as a driving source, the temperature of the motor is predicted based on information (temperature coefficient) related to the operating state of the motor and the accumulated rotational speed within a predetermined time. A method is described. The motor control mode is switched based on the predicted motor temperature. Further, in order to avoid the loss of information for predicting the temperature of the motor due to the hard power-off of the conveying device due to an unexpected power failure or the like, the information is stored in a non-volatile memory at regular intervals (for example, every 10 seconds) Is written to.

JP2013-155209A

  In the transport device described in Patent Document 1, information is written to the nonvolatile memory at regular time intervals (for example, every 10 seconds). When a nonvolatile memory that takes time to write information is used, the writing ends. There may be a time loss in control due to waiting. Further, when the motor is driven in the low speed mode in which the temperature rise is small, the frequency of writing information to the nonvolatile memory becomes higher than necessary. Inexpensive flash memory (EEPROM) among non-volatile memories has a limit on the number of times of writing. Therefore, if the frequency of writing increases, the period until the end of the memory life may be shortened.

  On the other hand, in order to accurately predict the temperature of the motor based on the information stored in the non-volatile memory at the time of restart after the transport device is hard-powered off due to a sudden power failure or the like, It is necessary to shorten the information writing interval. When the information writing interval is shortened, the ratio of the writing end waiting time to the writing interval increases, and there is a possibility that the control time loss due to the writing end waiting may be increased. Such a loss time is particularly noticeable when a flash memory (flash EEPROM) having a large unit for writing information and a slow writing speed is used as a non-volatile memory, although it has a large capacity and is inexpensive. For example, some flash memories require a maximum of 500 milliseconds to 1 second to write information per time. When information is written at an interval of 10 seconds in a flash memory that takes 1 second to write information at a time, the ratio of the waiting time for completion of writing to the write interval is 10%. When the write interval is halved, the ratio of the write end waiting time to the write interval increases to 20%, which may cause a control time loss.

  An object of the present invention is to provide an apparatus capable of accurately predicting a motor temperature, which can use an inexpensive non-volatile memory such as a flash memory that takes time to write information and has a limited number of times of writing, and The object is to provide a method for predicting motor temperature.

The conveying device of the present invention is a conveying device that conveys a sheet by a motor, an acquisition unit that acquires a coefficient for predicting a temperature of the motor from a driving condition of the motor, and a motor of the motor based on the coefficient prediction means for predicting the temperature, and the non-volatile memory, along with a flag which is turned on is stored in the nonvolatile memory when the operation with the sheet conveyance is performed by the motor, the obtained coefficients the motor Control means for storing the coefficient in the nonvolatile memory when the temperature change is equal to or higher than a predetermined temperature , and the prediction means turns on the power when the transport device is turned on. The last power-off before turning on was a soft power-off to shift to the power-saving standby mode, or the supply of power to the transport device was forcibly cut off. If the power-off is determined to be the hard power-off, it is read whether the state of the flag stored in the nonvolatile memory is on or off. When the flag is ON, the temperature of the motor is predicted using a value obtained by adding a predetermined correction value corresponding to the predetermined temperature to the coefficient stored in the nonvolatile memory as a new coefficient, When the flag is off, the motor temperature is predicted without adding the predetermined correction value to the coefficient stored in the nonvolatile memory .

  According to the present invention, when the information for predicting the temperature of the motor is information corresponding to a temperature increase of the motor more than a predetermined value, the information is stored in the nonvolatile memory. As a result, even if the nonvolatile memory takes time to write information, the temperature of the motor can be accurately predicted while suppressing the occurrence of a control loss time. In addition, since the frequency of writing to the nonvolatile memory is low, an inexpensive nonvolatile memory with a limited number of times of writing can be used, and the device cost can be reduced.

1 is an external perspective view of a recording apparatus with an image reading function according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of a conveyance unit in the recording apparatus of FIG. 1. FIG. 2 is an explanatory diagram of a driving mechanism of a conveyance unit in the recording apparatus of FIG. 1. FIG. 2 is a block diagram of a control system of the recording apparatus in FIG. 1. It is explanatory drawing of the relationship between the drive condition of a drive motor, and temperature. It is explanatory drawing of the relationship between the drive condition of a drive motor, and temperature. It is explanatory drawing of the relationship between a temperature coefficient and the drive amount of a drive motor. It is a flowchart for demonstrating the update process of a temperature coefficient. 6 is a flowchart for explaining data processing at the start of a job. It is explanatory drawing of the passage time of a temperature coefficient area. It is a flowchart for demonstrating the control at the time of starting of an apparatus.

  Embodiments for carrying out the present invention will be exemplarily described below with reference to the drawings. The image reading apparatus according to the present invention is configured as a single apparatus, and the image forming apparatus main body of the image forming apparatus such as a copying machine, a printer, a facsimile, and a multifunction machine of these is one of the constituent elements of the image forming apparatus. It is also possible to provide as a part. For example, an image can be read by an image reading device, and the image can be formed on a sheet by an image forming unit of the image forming device. In this case, the image read by the image reading device can be copied to a sheet by the image forming unit, and the image data can be transmitted to the external device through the communication unit.

(First embodiment)
The image reading apparatus of this embodiment is an application example as an image paper reading apparatus provided with a document feeding device.

  1, 2, and 3, the document reading / conveying unit 1 has a document conveying path (U-turn path) 12 formed in an automatic sheet feeding pressure plate unit 40. A document presence sensor 16 for detecting the presence or absence of the document S, a document edge sensor 17 for detecting the leading edge and the trailing edge of the document S, and the like are attached to the U-turn path 12.

  The document reading and conveying unit 1 is provided with a document placing tray 14 so as to be connected to the upstream end side of the U-turn path 12, and a document discharge tray 18 is provided on the downstream end side of the U-turn path 12. Further, on the upstream end side of the U-turn path 12, a pickup roller 3 for picking up the document S is provided in contact with the uppermost one of the documents S stacked on the document placement tray 14. The documents S picked up by the pickup roller 3 are separated one by one by the separation roller 5 and the separation pad 4 that are pressed against each other. A first conveying roller 7 is provided at an intermediate position of the U-turn path 12, and a second conveying roller 9 for discharging the document S to the document discharge tray 18 is provided at the downstream end side of the U-turn path 12. The document S placed on the reading glass 22 is read by the book document reading unit 2. A contact image sensor (hereinafter also referred to as “CIS”) 30 is disposed via the document reading and conveying unit 1 and the glass 22. The CIS 30 irradiates the image information surface of the document S with light from a light emitting unit (LED) mounted on the CIS 30, and forms reflected light reflected from the image information surface of the document S on a sensor element by a self-focusing rod lens array. Thus, the image information of the document S is read. The CIS 30 is configured to be movable in the left-right direction (arrows A1 and A2 directions) in FIG. 2. When reading a book document (flatbed scan), the CIS 30 moves on the reading glass 22 while moving in the arrow A1 direction. The original S placed on is read. When the original S is read by the original reading / conveying unit 1, the CIS 30 is stopped at the sheet original reading position (a position facing the reading white base plate 8), and image information on the surface of the original S conveyed to the reading position is displayed. , Read through the ADF glass 23.

  The drive motor M is a DC motor, and a slit pattern is printed on the code wheel film M1 disposed on the motor shaft. A rotary encoder M3 is disposed in the vicinity of the drive motor M, and the rotation amount of the drive motor M is detected by the encoder sensor M2 of the rotary encoder M3 reading the slit pattern of the code wheel film M1. Based on the pulse signal from the encoder M3, the rotation of the drive motor M is controlled by pulse width modulation (PWM) control. Each time the encoder sensor M2 detects one slit of the slit pattern, the document S is conveyed by 1/36000 inch at the reading position. Therefore, the reading resolution in the transport direction of the document S (hereinafter also referred to as “paper surface resolution”) is 1/36000 inch per slit.

  The driving force of the driving motor M is transmitted to the separation roller 5, the pickup roller 3, the first conveying roller 7, and the second conveying roller 9 by the gear train M4. When the operator gives an instruction to start reading from the operation unit E (see FIG. 1), the drive motor M rotates, the separation roller 5 and the pickup roller 3 rotate, and the pickup arm 10 descends and presses against the document S. Is done. The document S is fed into the U-turn path 12 by the rotation of the pickup roller 3. In the document reading / conveying section 1, the documents S are separated one by one by the separation roller 5 and the separation pad 4, and the uppermost document S is conveyed along the U-turn path 12, and further, by the first conveyance roller 7. It is conveyed to an image reading unit by the CIS 30. The separation roller 5 rotates at a peripheral speed slower than that of the first conveyance roller 7 and the second conveyance roller 9, and continuously rotates the drive motor M, whereby the first document S and the second document S A predetermined amount of space is formed between the two.

  In the document reading / conveying unit 1, the leading edge of the document S is detected by the document edge sensor (DES) 17. After the detection, the document S is transported by a predetermined amount, and then the document S is transported and the document S by the CIS 30. Reading of the image information on the surface of is started. When the document edge sensor 17 detects the trailing edge of the document S and when the document S is conveyed by a predetermined amount, reading of image information by the CIS 30 is finished. When there is a subsequent document S, the drive motor M is continuously rotated, the document is conveyed, and an image of the document S is read. Until the document presence sensor 16 detects that there is no subsequent document S, the conveyance of the document S and the reading of the image by the drive motor M are continued.

  FIG. 4 is a block diagram of a control system 300 of a recording apparatus provided with such an image paper reading apparatus.

  A main control IC 302 provided on the main control board 301 includes a microprocessor unit (MPU) 306, a read image processing unit 307, a recorded image processing unit 308, an image encoding unit 309, and the like. Control. The ROM 304 stores a program code for operating the MPU 306, initial value data, table data, and the like. The RAM 305 is used as a calculation buffer and an image memory. The reading unit 310 includes a CIS 30 (see FIG. 2), a read image correction unit 312, a reading system driving unit 313, and the like. The reading unit 310 drives the reading system driving unit 313 to move the CIS 30 as described above, and optically sequentially reads an image by the CIS 30 and converts it into an electrical image signal. This image signal is subjected to shading correction and the like by the read image correction unit 312, and further subjected to image processing by the read image processing unit 307 and output as high-definition image data.

  The recording unit 315 includes a recording system driving unit 318 that moves the recording head 316, and a recording signal output unit 317 that outputs the image data created by the recording image processing unit 308 to the recording head 316. The recording unit 315 drives the recording system driving unit 318 to move the recording head 316 to a predetermined position, and outputs image data from the recording signal output unit 317 to the recording head 316, thereby recording an image on a recording medium. To do. The recording method of the recording unit 315 is arbitrary. For example, an ink jet recording method using an ink jet recording head capable of ejecting ink may be used.

  The operation panel 320 outputs a display image to the display unit 321 via the operation panel interface unit 323 and receives an operation input from the operation unit 322. The audio output unit 325 converts audio data into a signal and outputs message audio from the speaker 326. The communication connection unit 327 is connected to the communication network 328 and the telephone 329 and inputs / outputs voice and encoded data. The encoded data is mutually converted into an image by the image encoding unit 309. The external interface unit 331 (for example, USB standard) is connected to an external device 332 such as a personal computer.

  The non-volatile memory 333 including a flash memory (EEPROM) can store such data so that work data and image data are not lost in the event of a power failure. The flash memory used as the non-volatile memory 333 has a large capacity and is inexpensive, but has a limitation such as a large information writing unit, a slow writing speed, and a small number of writable times until reaching the lifetime. These restrictions are avoided by usage specific to the present embodiment described later.

  The wireless LAN module 334 inputs and outputs images via an access point outside the apparatus. The power supply unit 340 supplies power necessary during the operation of the main control board 301, the reading unit 310, the recording unit 315, the operation panel 320, and the like.

  Next, the operation of the recording apparatus including such an image paper reading apparatus will be described separately for each of a PC scan operation, a copy operation, a facsimile reception operation, a recording operation, and a power-off process.

(PC scan operation)
Image information of the document S read by the CIS 30 of the reading unit 310 is first subjected to processing such as shading correction by the read image correction unit 312, and then developed in the RAM 305 as image data by the read image processing unit 307. The image data is compressed and encoded in, for example, JPEG format by the image encoding unit 309, and the encoded data is output to the external device 332 through the external interface unit 331.

(Copy operation)
Image information of the document S read by the CIS 30 of the reading unit 310 is first subjected to processing such as shading correction by the read image correction unit 312, and then developed in the RAM 305 as image data by the read image processing unit 307. The image data is temporarily stored in the image encoding unit 309 after being compressed and encoded in, for example, the JPEG format. The accumulated image data is sequentially sent to the recording image processing unit 308 and converted into a recording image. The recording image is output to the recording head 316 via the recording signal output unit 317, thereby being recorded on a recording medium such as recording paper.

(Facsimile transmission operation)
The image information of the document S read by the CIS 30 of the reading unit 310 is first subjected to processing such as shading correction by the read image correction unit 312 and then developed as image data in the RAM 305 by the read image processing unit 307. The image data is compressed and encoded, for example, in the MR (Modified Read) format by the image encoding unit 309 and then temporarily stored. Transmission of the stored image data is started after the communication connection unit 327 transmits / receives a facsimile communication procedure signal. It is possible to continue reading the image information after the start of transmission and continue transmission while accumulating image data.

(Facsimile reception operation)
When there is an incoming call from the communication network 328, the communication connection unit 327 transmits / receives a facsimile communication procedure signal and then starts receiving image data. The received image data is demodulated by the image encoding unit 309 and then expanded in the RAM 305. The expanded image data is sequentially sent to the recording image processing unit 308 and converted into a recording image. The recording image is output to the recording head 316 via the recording signal output unit 317, thereby being recorded on a recording medium such as recording paper.

(Recording operation)
A command and a reception parameter transmitted from the external device 332 and received by the external interface unit 331 are interpreted by the MPU 306 and developed in the RAM 305 as image data by the image encoding unit 309. The expanded image data is sequentially sent to the recording image processing unit 308 and converted into a recording image. The recording image is output to the recording head 316 via the recording signal output unit 317, thereby being recorded on a recording medium such as recording paper.

(Power off processing)
When the operator presses the power button of the operation unit E while the apparatus is being activated, each part of the apparatus is shut down, and the apparatus enters a power saving standby (soft power off) state. When entering the soft power off state, the MPU 306 writes in the nonvolatile memory 333 so as to turn on the power supply normal off flag. In addition, when the operator presses the power button of the operation unit E in the soft power off state, after the power normal off flag is turned off, the apparatus enters a state (soft power on state) for accepting the normal operation of the operator. Then, start the device. In the soft power-off state, since power is supplied to the device, the period of the soft power-off state can be calculated by continuously operating a timepiece device (not shown). The device of this example does not include a battery that continuously supplies power to the timepiece device. Therefore, in a state where the supply of power to the apparatus is cut off (hard power off), it is not possible to calculate the period during which the soft power off state has occurred. However, by reading data from the nonvolatile memory 333, it is possible to recover the flag setting state before the supply of power is cut off.

  When the power supply is supplied (hard power-on) after the hard power-off when the power supply is cut off, the initial startup program is executed first to check whether the power normal off flag is on. judge. If it is on, it is determined that the normal shutdown control has been performed, and after the power supply normal off flag is turned off, a transition to the soft power off state is made. On the other hand, when the power normal off flag is off, it is determined that an abnormal power supply interruption (power failure) has occurred, and the soft power on state is automatically restored without waiting for the operator to operate the power button on the operation unit E. Thus, a normal operation is accepted. Thus, the apparatus can return to the original state before the occurrence of the hard power off, regardless of whether it is in the soft power off state or the normal operation state.

(Temperature coefficient)
Next, the temperature coefficient of the drive motor M will be described with reference to FIGS.

  The temperature coefficient of the drive motor M is a virtual coefficient that predicts the temperature of the drive motor M. The temperature coefficient is a numerical value corresponding to the temperature rise (° C.) of the motor case with reference to the motor case temperature when the temperature of the motor case is at room temperature due to the drive motor M being stopped for a long time. It is.

  5 and 6 show experimental data when the original S is actually conveyed using a φ25 mm DC motor as the drive motor M. FIG. Hereinafter, the details of the temperature coefficient will be described using the experimental data. The experiment was carried out with the conveyance speed of the document S being 8 ipm (8 sheets / min) and 4 ipm (4 sheets / min). 5 and 6, the use of the apparatus is predicted for the “motor case temperature” at which the case of the drive motor M is measured and the “outer wall temperature” at which the outer wall of the cover near the drive motor M is the measurement point. The temperature rise value from 35 ° C., which is the maximum ambient temperature to be performed.

  FIG. 5 shows the temperature rise value of the peripheral portion of the drive motor M with respect to the operation time of the drive motor M. Depending on the conveyance speed of the document S, both the motor case temperature and the outer wall temperature rise differently. In order to predict the temperature rise from the operation time of the drive motor M, it is necessary to consider the drive speed of the drive motor M corresponding to the conveyance speed of the document S, but it is difficult to support a large number of drive speeds. . The descending curve in the graph of FIG. 5 shows the temperature decline after the drive motor M stops, and the descending curve does not depend on the conveyance speed of the document S. Therefore, for the temperature drop value after the stop of the drive motor M, the drop value depends on the elapsed time after the stop, so a prediction formula can be established.

FIG. 6 shows the relationship between the number of conveyed A4-size originals S and the temperature rise value. In the process of increasing the temperature from the start of the operation of the drive motor M, it has been found that if the number of documents S conveyed is the same, that is, if the rotation amount of the drive motor M is the same, the temperature increase value is approximately the same. The temperature difference due to the difference in the conveyance speed of the document S is about 3 ° C. at maximum. By incorporating this temperature difference as a margin, the temperature rise value is predicted using the rotation amount of the drive motor M per unit time. You can make a formula. The calculation formula representing the temperature coefficient during the operation of the drive motor M can be expressed by the following formula (1) from the approximate formula of the curve in FIG.
Temperature coefficient = “temperature constant” × “current temperature coefficient” + “rate constant” + “intercept” (1)
Temperature constant ": -0.00095
“Speed constant”: 4.5 × 1.00E-07
“Section”: 0.03
Moreover, the calculation formula showing the temperature coefficient at the time of the stop of the drive motor M can be made into the following Formula (2) from the approximate formula of the curve in FIG.
Temperature coefficient = “A” × “current temperature coefficient” ² + “B” × “current temperature coefficient” (2)
“A”: −0.000017
“B”: −0.0002

  FIG. 7 shows a value obtained by converting the temperature coefficient calculated by such an expression by the number of output pulses of the rotary encoder M3. A parameter related to the amount of rotation of the drive motor M in one second (converted to the number of output pulses of the rotary encoder M3) is added to or subtracted from the current temperature coefficient T. In order to improve the calculation speed, the temperature coefficient in FIG. 7 is divided into predetermined ranges according to the rotation amount (drive distance) of the drive motor per second. The temperature coefficient is used for predicting a predicted temperature rise from an ambient room temperature (for example, 35 ° C.) where the apparatus is assumed to be used, and is 0 when the apparatus is stopped for a long time. As shown in FIG. 7, by converting the temperature coefficient into the number of output pulses of the rotary encoder M3 and making a table, it is not necessary to perform floating point multiplication as in the above equation during actual operation, and calculation by the MPU 306 is performed. The load can be reduced. The number of columns in the temperature coefficient table may be increased or decreased according to the desired calculation accuracy. If the calculation load is not a problem, the number of columns may be calculated each time the temperature coefficient is updated. .

(Temperature coefficient update method)
Next, a method for updating the temperature coefficient of the drive motor during operation of the apparatus will be described with reference to FIG.

  FIG. 8 is a flowchart for explaining the update process of the temperature coefficient of the drive motor.

  First, the current temperature coefficient is acquired and stored in a predetermined location on the RAM 305 (step S21). When the temperature coefficient is updated for the first time after the start of the reading job, the temperature coefficient acquired in step S21 is stored in a dedicated area on the RAM 305 as the temperature coefficient at the start of the job (steps S22 and S23). Next, the drive distance per second of the drive motor M is calculated (step S24). The driving distance can be calculated based on a value (slit / second) obtained by counting the number of slits detected by the encoder sensor M2 every second.

  Next, the temperature coefficient is updated by adding the difference parameter calculated from the operating state of the drive motor M to the latest temperature coefficient acquired in step SS21 (step S25). The updated temperature coefficient is registered in the write preparation area of the nonvolatile memory 333 on the RAM 305, that is, the RAM 305 which is a volatile memory (step S26). Next, it is determined whether the current operation mode of the apparatus is a normal mode or a temperature rise suppression mode described later (step S27). In the temperature raising mode, it is determined whether or not the temperature coefficient is less than the threshold value TL (step S28). When the temperature threshold value <TL, the temperature raising mode is changed to the normal mode (step S29), and then step S30. Proceed to

  If it is determined in step S27 that the apparatus is not in the temperature raising mode (in the normal mode), it is determined whether or not the temperature coefficient exceeds a threshold value TH (TH> TL) (step S34). When the temperature threshold value> TH, after the transition from the normal mode to the temperature raising mode (step S35), the process proceeds to step S30. On the other hand, when the temperature threshold value ≦ TH, the temperature coefficient is less than the threshold value TC (TC <TL <TH). Whether or not (step S36). If the temperature coefficient <TC, the process proceeds to step S37, the job confirmation flag and the job processing flag are turned off, and the job confirmation flag (off) and the job processing flag (off) are stored in the nonvolatile memory 333 on the RAM 305. Register in the write preparation area. That is, the job confirmation flag (off) and the job processing flag (off) are registered in the RAM 305 which is a volatile memory. If the temperature coefficient is equal to or greater than TC (temperature coefficient ≧ TC), the process proceeds to step S30.

  In step S30, whether or not the value of the change from the temperature coefficient at the start of the reading job acquired in step S23 to the current temperature coefficient has exceeded one of a plurality of predetermined write thresholds TW. Determine whether. That is, it is determined whether or not the temperature coefficient at the start of the reading job has increased to the current temperature coefficient and the increased value has exceeded one of the write threshold values TW. If the temperature coefficient rise value exceeds one of the write threshold values TW, has the temperature coefficient rise value exceeded the write threshold value TW to write the temperature coefficient into the nonvolatile memory 333 as a trigger? It is determined whether or not (step S32). If it has not been performed, the temperature coefficient is written in the nonvolatile memory 333 in step S33, and then the process proceeds to step S31. If it has been performed, the process proceeds to step S31. If it is determined in step S30 that the temperature coefficient increase value does not exceed the write threshold TW upward, the process proceeds to step S31. In step S31, the process waits for 1 second, and then returns to the previous step S21.

(Normal mode and temperature rise suppression mode)
Next, a normal mode and a temperature rise suppression mode as control modes of the drive motor M will be described.

  In the normal mode, the reading speed of the document S is a conveyance speed V set in accordance with the operation limit speed of the CIS 30, the processing speed of the main control IC 302, the number of read colors of the image, and the reading resolution. The drive motor M is feedback-controlled using a pulse signal from the rotary encoder, and conveys the document S at the conveyance speed V. In the normal mode, document images are continuously read as long as a predetermined amount of image buffer capacity on the RAM 305 is secured. If the remaining capacity of the image buffer becomes smaller than that of one original S during the reading, the reading operation is temporarily stopped without reading the next original S, and the image data in the image buffer is stopped. It waits for the free space in the image buffer generated by the processing.

  The temperature increase mode is a mode in which the reading operation is continuously performed while maintaining the state where the temperature of the drive motor M does not rise so as not to stop the image reading operation. The temperature rise during continuous rotation of the drive motor M depends on the amount of rotation. For this reason, when the reading speed is simply reduced, the reading time is increased, and the temperature rise of the drive motor M cannot be suppressed. Further, when the reading operation is stopped between the preceding document S and the succeeding document S and the temperature of the drive motor M is decreased, the reading operation is resumed after waiting for the temperature to decrease. It takes a long time. In this case, since the transmission interval of the image data becomes long, there is a possibility that the receiving side apparatus determines that a communication failure has occurred and a time-out error occurs during facsimile transmission, and communication is disconnected.

  Therefore, in this example, the temperature raising characteristic of the drive motor M is used, and in the temperature raising mode, a reading operation of reading 540 lines of an original image with a resolution of 300 dpi (approximately 0.8 seconds including the maximum speed V, acceleration, and deceleration time). And the reading operation is stopped for 1 second. By performing the reading operation in this cycle and continuing to send the read data, the data can be periodically sent to the receiving side apparatus, and the occurrence of a timeout error can be suppressed.

  Thus, in this example, the control mode (normal mode and temperature rise suppression mode) of the drive motor M is switched based on the predicted temperature of the drive motor M.

(Power-off monitoring process)
Next, the power-off monitoring process during execution of a reading job will be described with reference to FIG.

  After the reading job is started, it is first determined whether or not the job confirmation flag is on (step S41). If it is on, the job processing flag is turned on, the job processing flag (on) is written in the nonvolatile memory 333 (step S42), and the process proceeds to step S43. If the job confirmation flag is not on, the process proceeds to S43 and waits for the end of the reading job. If the completion of the reading job is confirmed, the job processing flag is turned off, and the job processing flag (off) and the temperature coefficient are written in the nonvolatile memory 333 (step S44).

  As described above, since the job processing flag is turned on only during the execution of the reading job, if a power failure occurs during the execution of the reading job, the supply of power is cut off while the job processing flag is on. Will be. In that case, since the job processing flag remains on when the apparatus is subsequently started up, it is possible to determine whether or not a power failure has occurred during the execution of the reading job. The execution of the reading job includes the driving of the driving motor M.

  In step S44, the temperature coefficient is written to the nonvolatile memory 333 by using the rising value of the temperature coefficient to exceed the write threshold value TW as a trigger, so that the number of times of writing to the nonvolatile memory 333 can be suppressed. . In particular, in the low-speed reading mode in which the temperature rise is small compared with the operation time of the drive motor M, the number of times of writing to the nonvolatile memory 333 can be suppressed. When the increase value of the temperature coefficient during execution of one reading job does not exceed the threshold value TW, it is not necessary to write the temperature coefficient into the nonvolatile memory 333 during execution of the reading job. The lower the temperature coefficient, the longer the time required to decrease by 1 ° C. after the drive motor M is stopped. In this example, the threshold TC is set to 2. In this example, the time required for the temperature coefficient to drop from 2 to 1 corresponding to the lowest temperature is about 4600 seconds. By increasing the threshold TC by 1 from 1 corresponding to the lowest temperature, the subsequent processing can proceed without waiting for the temperature coefficient to fall to the lowest temperature, and the threshold TC is set to 1 corresponding to the lowest temperature. Compared to the case, the subsequent processing can be accelerated by one hour or more.

  In this example, the write threshold TW is set in increments corresponding to a temperature of 5 ° C., and the value of the temperature coefficient increases by a temperature equivalent to 5 ° C., 10 ° C., 15 ° C., 20 ° C., 25 ° C., 30 ° C.,. Every time, the temperature coefficient is written into the nonvolatile memory 333. That is, when the temperature coefficient is a temperature coefficient corresponding to a temperature change (temperature increase) of the drive motor M at a predetermined level or higher (5 ° C. or higher), the temperature coefficient is written (data rewriting) into the nonvolatile memory 333. Therefore, for example, in FIG. 10, when the driving speed of the driving motor M is 80000 (slit / second) or less and the temperature coefficient increases at the highest speed by 5 ° C. from 10 to 15, about 78 seconds, Writing the temperature coefficient to the nonvolatile memory 333 is not necessary. Since the writing unnecessary period becomes longer as the driving speed of the driving motor M becomes lower, the writing frequency can be greatly reduced as compared with the case where the temperature coefficient is periodically written. For this reason, even if the nonvolatile memory 333 is a flash memory with a limited number of writes, there is a sufficient margin until the memory life is reached.

  The setting interval of the write threshold TW is preferably set according to the operating speed of the drive motor M and the time required for the temperature rise. The apparatus of this example can read an A4 size document S at a maximum of 10 sheets / minute (one sheet is about 6 seconds). When the drive motor M is driven at the maximum speed, the writing threshold value TW is set in increments of 5 ° C., so that the reading to the nonvolatile memory 333 is performed during the reading period of about 10 documents S per reading job. There is no need to write the temperature coefficient. Therefore, the reading job for reading about 10 originals S is completed without writing the temperature coefficient in the nonvolatile memory 333. In general consumer devices that are not for business use, it is rare that the number of documents read per reading job exceeds 10. In such a general consumer device, writing of the temperature coefficient to the nonvolatile memory 333 can be avoided during execution of many reading jobs. In this example, the setting interval of the write threshold TW is set uniformly regardless of the drive speed of the drive motor M, but may be set for each predetermined drive speed range of the drive motor M.

(Control at startup)
Next, the control at the time of starting the apparatus will be described with reference to FIG. When the apparatus is activated by soft power-on, first, a known activation sequence is executed to self-diagnose whether there is an abnormality in the hardware (step S1). Next, it is determined whether or not the apparatus is activated for the first time after the hard power is turned off after the power supply voltage is cut off (step S2). The fact that the current activation is not the first activation after the hard power off means that the apparatus was in the power saving mode connected to the power supply before the current activation. In this case, based on the elapsed time of an internal timer (not shown), the temperature coefficient registered in the RAM 305 is updated (step S3), and the temperature coefficient update process shown in FIG. 8 is executed (step S4). .

  If it is determined that the current activation is the first activation after the hard power off, the temperature coefficient stored in the RAM 305 is lost, so the temperature coefficient stored in the nonvolatile memory 333 is read. It is set as an initial value (step S5). After that, the elapsed time from the hard power-on when the supply of power is resumed due to power failure recovery to the current soft power-on is obtained from the internal timer, and the temperature coefficient is updated based on the elapsed time. Save in the RAM 305 (step S6). Next, it is determined whether or not the current soft power-on is due to an automatic return from the hard power-off that occurred in the previous soft power-on state (step S7). If the current soft power-on is not due to an automatic return from the hard power-off, there is no need to perform a forcible addition process to be described later on the temperature coefficient stored in the nonvolatile memory 333. Therefore, in this case, the above-described temperature coefficient update process (temperature coefficient storage control) in FIG. 8 is executed (step S4).

  On the other hand, if it is determined that the current soft power-on is not due to an automatic return from the hard power-off, the process proceeds from step S7 to step S8, where it is determined whether the job confirmation flag is on. When the job confirmation flag is on, the temperature coefficient is stored in the nonvolatile memory 333 at the start of the reading job, and the stored temperature coefficient needs to be subjected to a forced addition process described later. Absent. That is, there is no need to perform a forced addition process, which will be described later, at the start of driving of the drive motor M. Therefore, in this case, the above-described temperature coefficient update processing of FIG. 8 is executed (step S4) on condition that the job processing flag is OFF (step S13). When the job confirmation flag is off, the process proceeds from step S8 to step S9.

When the job confirmation flag is on , the actual temperature coefficient increases between the hard power off and the hard power on, and the value is higher than the temperature coefficient stored in the nonvolatile memory 333. It may have become. In this case, the temperature coefficient stored in the non-volatile memory 333 is forcibly added (temperature coefficient forcible addition process) that may have been lost due to a hard power-off such as a power failure. (Step S9). In this example, the write threshold TW is set in increments of 5 ° C. Therefore, with respect to the temperature coefficient stored last in the nonvolatile memory 333, the maximum error (+ 5 ° C. in this embodiment) that may increase in temperature during the period from the last storage until the hard power is turned off. Forcibly add the corresponding value. That is, after the last information writing to the nonvolatile memory, the temperature is predicted by adding the value of a predetermined temperature coefficient that anticipates the worst case in which the temperature may change most greatly while information is missing.

  Thereafter, it is determined whether or not the temperature coefficient after such forced addition exceeds the maximum value TMAX (46 in the present embodiment) in the range of the temperature coefficient table of FIG. 7 (step S10). If temperature coefficient ≦ TMAX, the process proceeds to step S12. If temperature coefficient> TMAX, the temperature coefficient is TMAXed (step S11), and then the process proceeds to step S12. When the temperature coefficient is TMAX, the temperature coefficient mode is immediately shifted to the temperature raising mode (step S35 in FIG. 8), so that the temperature coefficient exceeding TMAX does not need to be forcibly added. In step S12, the job confirmation flag is turned on, the job processing flag is turned off, and the job confirmation flag (on) and the job processing flag (off) are registered in the RAM 305, which is a volatile memory. For the nonvolatile memory 333, when the device is shipped from the factory, the initial value of the temperature coefficient (0 in this example), the initial value of the job confirmation flag (off in this example), the initial value of the job processing flag A value (in this example, OFF) is written in advance.

  In this embodiment, after a hard power-off due to a power failure or the like, if the reading job does not occur for a predetermined time or more, the temperature coefficient falls below the lower limit threshold TC, and the job confirmation is performed in step S37 in FIG. The flag is automatically cleared (off). Therefore, when a reading job does not occur immediately after a power failure or the like, the job confirmation mode for writing the temperature coefficient in the nonvolatile memory 333 is not executed at the start of the reading job. When the temperature coefficient is less than the lower limit threshold value TC, the job confirmation flag remains on, so that the job confirmation mode for writing the temperature coefficient in the nonvolatile memory 333 is not executed at the start of the reading job. Therefore, the threshold value TC sets one condition that determines whether or not to write a temperature coefficient in the nonvolatile memory 333 at the start of the reading job. When the temperature coefficient is equal to or higher than a predetermined temperature of the drive motor (threshold value TC or higher), the temperature coefficient is written in the nonvolatile memory 333 at the start of the reading job.

  As described above, by automatically canceling (turning off) the job confirmation flag in step S37 in FIG. 8, the number of times of writing of the temperature coefficient to the nonvolatile memory 333 at the start of the read job and during the execution of the read job is determined. Can be reduced. As a result, it is possible to stably execute the reading operation by reducing the possibility of stopping a series of reading operations that may occur when the writing process is frequently performed. In addition, the present embodiment can employ an inexpensive flash memory (EEPROM) because the frequency of writing to the nonvolatile memory is low.

  In addition, when the power is turned off due to a power failure or the like, at the time of recovery, the non-volatile value is finally set to a predetermined value that anticipates the worst case that may cause the largest temperature fluctuation while information is missing since the last writing of information. In addition to the value stored in the memory, the motor temperature is predicted. Since a battery-backed watch that keeps timing during a power outage is not required, coupled with the adoption of an inexpensive flash memory, the cost of the device can be reduced.

(Second Embodiment)
In the above-described embodiment, the temperature coefficient in the above-described embodiment is updated in association with the recording unit 315 and the control.

  When a hard power down occurs due to a power failure or the like during execution of a recording job, the recording unit 315 stores information necessary for control of the subsequent recording operation in the nonvolatile memory as in the execution of the reading job in the reading unit 310. Write to 333. For example, during execution of a double-sided recording job in which the recording unit 315 records an image on both sides of a recording medium, a recording surface flag indicating whether recording on the front surface of the recording medium or recording on the back surface thereof is performed. Write to the non-volatile memory 333. For example, the write area (block) of the recording surface flag and the temperature coefficient of the recording unit 315 described above is set in the RAM 305, and when any of them is written, both of them are stored in the nonvolatile memory 333. Configure to write.

  With this configuration, when the original S is copied on both sides, the temperature coefficient is stored in the nonvolatile memory 333 each time the recording surface flag of the recording unit 315 is rewritten by changing the recording surface of the image on the recording medium. Will be written. More specifically, on the condition that the recording surface flag is rewritten after the start of the double-sided recording job, the temperature coefficient is written into the nonvolatile memory 333 every time the recording surface changes by executing step S33 of FIG. In that case, the temperature coefficient is written in the nonvolatile memory 333, triggered by an increase in the temperature coefficient with respect to the temperature coefficient written in the nonvolatile memory 333 exceeding the write threshold TW. As a result, in association with the recording unit 315 and the control, the number of times of writing the temperature coefficient to the nonvolatile memory 333 can be reduced.

(Other embodiments)
The present invention can not only predict the temperature of the motor provided in the sheet conveying apparatus, but also can predict the temperature of the motor provided in the apparatus in various apparatuses. In other words, the present invention can be widely applied to various devices that perform various operations by the driving force of a motor that is driven by the supply of power supply power and that has different degrees of heat generation according to driving conditions. The driving condition of the motor can include at least one of a driving speed, a driving time, and a driving amount of the motor.

  The predicted motor temperature can be used not only for switching the motor control mode but also for controlling various devices such as a cooling device.

305 RAM (volatile memory)
310 Reading unit 315 Recording unit 316 Recording head 333 Non-volatile memory S Document (sheet)
M drive motor

Claims (11)

A conveying device that conveys a sheet by a motor,
Obtaining means for obtaining a coefficient for predicting the temperature of the motor from the driving conditions of the motor;
Predicting means for predicting the temperature of the motor based on the coefficient ;
And the non-volatile memory,
A flag that is turned on when an operation involving sheet conveyance by the motor is performed is stored in the nonvolatile memory, and the obtained coefficient indicates a temperature change equal to or higher than a predetermined temperature of the motor. Control means for storing the coefficient in the nonvolatile memory;
Equipped with a,
The prediction means includes
When the transport device is turned on, whether the last power-off before turning on the power was a soft power-off for shifting to the power-saving standby mode, or the supply of power to the transport device is forcibly Determine if it was a hard power off,
If it is determined that the power off is the hard power off, read whether the state of the flag stored in the nonvolatile memory is on or off,
When the flag is ON, the temperature of the motor is predicted using a value obtained by adding a predetermined correction value corresponding to the predetermined temperature to the coefficient stored in the nonvolatile memory as a new coefficient,
When the flag is off, the temperature of the motor is predicted without adding the predetermined correction value to the coefficient stored in the nonvolatile memory . A volatile memory for storing the coefficient acquired by the acquisition means during operation of the transport device;
The predicting means predicts the temperature of the motor based on the coefficient stored in the volatile memory or the nonvolatile memory.
Said control means, said the coefficients in the volatile memory is stored is stored in the nonvolatile memory and said Rukoto, conveying device according to claim 1. The said prediction means predicts the temperature of the said motor based on the said coefficient memorize | stored in the said non-volatile memory, when the contents of the said volatile memory are lose | disappeared by the said hard power-off. Item 3. The transfer device according to Item 2. The predicting means updates the coefficient stored in the volatile memory to predict the temperature of the motor when it is determined that the power-off is the soft power-off . The conveyance apparatus of any one of Claim 1 to 3 . The driving conditions, the driving speed of the motor, driving time, and characterized in that it comprises at least one of the driving amount, the conveying device according to any one of claims 1 to 4. During operation of the apparatus, on the basis of the temperature of the motor, which is predicted by the prediction means, characterized in that it comprises a mode switching means for switching the control mode of the motor, according to any one of claims 1 5 Transport device. Said control means, when the driving start of the motor, characterized Rukoto is stored the coefficients in the nonvolatile memory, the conveying device according to any one of claims 1 to 6. Characterized in that said non-volatile memory is EEPROM, conveying device according to any one of claims 1 to 7. A transport device according to any one of claims 1 to 8 ,
Reading means for reading an image recorded on a sheet conveyed by the conveying device;
An image reading apparatus comprising: A transport device according to any one of claims 1 to 8 ,
A recording means for recording an image on a sheet conveyed by the conveying device;
A recording apparatus comprising: A method for predicting the temperature of the motor based on the driving conditions of the motor,
Obtain a coefficient for predicting the temperature of the motor from the driving conditions of the motor,
The coefficient flag which is turned on with is stored in the nonvolatile memory, when the obtained the coefficient is indicative of the temperature variation of the predetermined amount or more of the motor when operating with the sheet conveyance by the motor is being performed It was stored in the nonvolatile memory,
When the transport device is turned on , whether the last power-off before turning on the power was a soft power-off for shifting to the power-saving standby mode, or the supply of power to the transport device is forcibly Determine if it was a hard power off,
If it is determined that the power off is the hard power off , read whether the state of the flag stored in the nonvolatile memory is on or off,
When the flag is ON, the temperature of the motor is predicted using a value obtained by adding a predetermined correction value corresponding to the predetermined temperature as a new coefficient to the coefficient stored last in the nonvolatile memory,
When the flag is off, the motor temperature is predicted without adding the predetermined correction value to the coefficient stored last in the non-volatile memory .