Conveying device, recording device, control method and program for conveying device

Abstract

To provide a conveying device that enables conveying operations while maintaining productivity. [Solution] One embodiment of the present disclosure is a transport device comprising: a transport roller for transporting a recording medium; a transport motor that generates a driving force for driving the transport roller; an encoder for detecting the rotation of the transport motor; a control unit that performs servo control of the transport motor based on an encoder signal output by the encoder, the control unit having a signal generation unit that generates a PWM signal; a motor driver that controls the transport motor based on the PWM signal output by the control unit; and a detection means for detecting the ambient temperature, wherein the control unit performs a temperature rise determination operation that determines whether the PWM value of the PWM signal is greater than a PWM threshold determined according to the ambient temperature, and changes the drive pattern of the transport motor when it is determined that the temperature has risen.

Description

Technical Field

[0001] The present disclosure relates to a conveying apparatus, a recording apparatus, a control method for a conveying apparatus, and a program.

Background Art

[0002] In recent years, many conveying apparatuses and recording apparatuses employ a DC motor as a drive source, and adopt servo control capable of performing high-precision position control by feeding back position detection information from an encoder. When a DC motor continuously performs conveying operations and recording operations, its temperature rises, the output torque decreases, and eventually the control accuracy may degrade. For this reason, countermeasures such as processing to lower the motor drive speed by detecting a temperature rise of the DC motor, and providing a wait operation between drives have been implemented.

[0003] Patent Document 1 discloses a method of estimating a temperature rise state based on a voltage value (PWM value) applied to the motor that is a result of feedback control, as temperature rise detection means for the motor. This method does not require a sensor for acquiring the motor temperature, and is a method that enables low-cost detection.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0005] However, Patent Document 1 does not take into account the temperature of the environment where the apparatus is installed. That is, it does not consider that when the outside air temperature of the apparatus is low or high, the winding resistance value or magnetic force of the DC motor may change, or the load of the apparatus main body itself may fluctuate. In such a case, the magnitude of the PWM signal changes even at the same motor temperature, and it is not possible to always determine that a temperature rise state is present at a constant motor temperature.

[0006] Therefore, if a threshold is set to determine that the motor temperature should be kept below a certain value at ambient temperatures (high temperatures) where it is difficult to detect motor temperature rise, then at ambient temperatures (low temperatures) where temperature rise is easily detected, the system will determine that the motor has risen even if it has not risen significantly. As a result, a weight operation for the purpose of suppressing temperature rise may be inserted at an earlier stage, leading to a problem of reduced productivity in the transport operation of the recording medium and the recording operation of the recording medium. [Means for solving the problem]

[0007] Therefore, in view of the aforementioned issues, this disclosure aims to provide a conveying device that can maintain productivity while suppressing the influence of the temperature of the environment in which it is installed.

[0008] One embodiment of the present disclosure is a transport device comprising: a transport roller for transporting a recording medium; a transport motor for generating a driving force to drive the transport roller; an encoder for detecting the rotation of the transport motor; a control unit for performing servo control of the transport motor based on an encoder signal output by the encoder, the control unit having a signal generation unit for generating a PWM signal; a motor driver for controlling the transport motor based on the PWM signal output by the control unit; and a detection means for detecting the ambient temperature, wherein the control unit performs a temperature rise determination operation that determines whether the PWM value of the PWM signal is greater than a PWM threshold determined according to the ambient temperature, and changes the drive pattern of the transport motor if it is determined that the temperature has risen. [Effects of the Invention]

[0009] According to this disclosure, it is possible to provide a conveying device that can maintain productivity while minimizing the effects of the temperature of the environment in which it is installed. [Brief explanation of the drawing]

[0010] [Figure 1] Perspective view of an inkjet recording device [Figure 2]Perspective view of the main body of the inkjet recording device. [Figure 3] Cross-sectional view of the transport path of an inkjet recording device. [Figure 4] Diagram showing the configuration of the carriage unit. [Figure 5] Block diagram showing the control system of an inkjet recording device. [Figure 6] Control flow for recording operation involving motor temperature rise control [Figure 7] Diagram explaining the recording mode [Figure 8] Processing flow for temperature rise detection operation [Figure 9] Diagram illustrating the temperature rise detection process. [Figure 10] Diagram illustrating the method for determining the PWM threshold. [Modes for carrying out the invention]

[0011] [First Embodiment] <Overall configuration of an inkjet recording device> The outline of the inkjet recording apparatus (hereinafter referred to as the recording apparatus) in this disclosure will be described below with reference to Figures 1 to 3. Figure 1 is a perspective view of the recording apparatus 100. Figure 2 is a perspective view of the main body of the recording apparatus 100. Figure 3 is a cross-sectional view of the recording apparatus 100.

[0012] An automatic document scanning unit 200 is positioned above the recording device 100, and the main body 50 of the recording device 100 is positioned below it. An operation panel 300 is positioned on the upper front of the recording device 100. A cassette 12 for setting recording media is provided below the main body 50.

[0013] When recording is performed in the recording device 100, the uppermost recording medium set in the cassette 12 is fed by the feed roller 31. The recording medium fed by the feed roller 31 is sandwiched between the intermediate roller 32 and the intermediate pinch roller 33 and transported to the transport roller 1. After the leading edge of the recording medium is brought against the transport roller 1 to correct its skew, it is sandwiched between the transport roller 1 and the pinch roller 2 that follows it, and is transported in the Y direction in the figure while being guided and supported on the platen 3 by the rotation of the transport roller 1. The transport roller 1 is a metal roller processed to generate a large frictional force by forming fine irregularities on its surface. The pinch roller 2 is elastically biased against the transport roller 1 by a pressing means such as a spring (not shown). The platen 3 supports the back surface of the recording medium so as to maintain a constant or predetermined distance between the ink ejection surface of the recording head 4 and the surface of the recording medium facing it. The recording medium, once transported onto the platen 3, is then sandwiched between the discharge roller 34 and a spur 35, which is a rotating body that follows the discharge roller, and transported thereafter. The discharge roller 34 is a rubber roller with a high coefficient of friction. The spur 35 is elastically biased against the discharge roller by a pressing means such as a spring (not shown). After image recording by the recording head 4 is performed, the recording medium is discharged from the platen 3 to the outside of the machine by the rotation of the discharge roller 34.

[0014] The recording head 4 is mounted on the carriage 7 in a position for ejecting liquid such as ink toward the recording medium, and is detachably attached to the carriage 7. The carriage 7 is moved back and forth along a guide rail 6 located at the top and a guide rail 5 located at the bottom, by a drive means such as a motor. The direction in which the carriage moves back and forth is intersecting (orthogonal in this example) the transport direction of the recording medium (Y direction), and is called the "main scanning direction (X direction)". In contrast, the transport direction of the recording medium is called the "sub-scanning direction (Y direction)".

[0015] The recording head 4 is composed of a black head that ejects black ink (K ink) and a color head that ejects color ink (C ink). The recording head 4 of the present embodiment is provided with a unit (for example, a heating resistor element) that generates thermal energy as energy used for ink ejection, and adopts an inkjet recording method that causes a state change (film boiling) of ink by the thermal energy. Thereby, high density and high definition of recording are realized. Note that the present embodiment is not limited to such a method using thermal energy, and a method using vibration energy may be adopted.

[0016] In a non-recording area that is within the reciprocating movement range of the recording head 4 and outside the passage range during conveyance of the recording medium, the blade unit 10 and the cap unit 11 are arranged so as to face the ink ejection port surface of the recording head 4. The blade unit 10 has a cleaning blade for wiping dirt on the ink ejection port surface, a preliminary ejection port 101 that receives ink discharged from the recording head 4, and a waste ink holding portion that holds waste ink. The cap unit 11 has a cap 111 for capping the ink ejection port surface of the recording head 4.

[0017] <Configuration of Carriage Unit> FIG. 4 is a diagram showing the configuration of a carriage unit configured to include the carriage 7 in the present embodiment. FIG. 4(a) is a perspective view of the carriage unit, and FIG. 4(b) is a perspective view of the carriage substrate 71 to which the carriage 7 is attached.

[0018] The carriage unit has a carriage board 71 that holds connectors 711 and 712 that electrically connect to the recording head 4. A temperature sensor (not shown) is mounted on the carriage board 71. In this embodiment, the ejection conditions of the recording head 4 are changed according to the ambient temperature, and the aforementioned temperature sensor is used to detect the (estimated) ambient temperature. The timing for performing ambient temperature detection by the temperature sensor can be anytime between when the power of the recording device 100 is turned on and the temperature sensor is energized and ready for use, and when the feeding roller 31 performs the first feeding operation of the recording medium. In this disclosure, the temperature sensor is also referred to as the ambient temperature detection means.

[0019] <Control system for recording device> Figure 5 is a block diagram showing the control system of the recording device 100. The MPU 201 controls the entire recording device 100, including the operation of each unit and data processing. The ROM 202 stores programs and various data executed by the MPU 201. The RAM 203 temporarily stores processing data executed by the MPU 201 and data received from the host computer 214. In this disclosure, the MPU is also referred to as the control unit.

[0020] The recording head 4 is controlled by the recording head driver 208. The carriage motor 204 that drives the carriage 7 is controlled by the MPU 201 and motor driver 209 based on electrical signals from the carriage motor encoder 221. The carriage motor encoder 221 is a sensor that detects the rotation of the carriage motor 204, acquires information such as the rotation angle, rotation speed, and rotation direction, and converts the acquired information into an electrical signal (a so-called encoder signal).

[0021] The transport roller 1, discharge roller 34, feed roller 31, and intermediate roller 32 are driven by a driving force transmitted from the transport motor 205. The transport motor 205 is a DC motor that functions as the driving force source for these motors. The transport motor encoder 222 is a sensor that detects the rotation of the transport motor 205, acquires information such as the rotation angle, rotation speed, and rotation direction, and converts the acquired information into an encoder signal. The transport motor 205 is controlled by the MPU 201 and motor driver 209 based on the encoder signal from the transport motor encoder 222. The scanner motor 206 that drives the automatic document scanning unit 200 is controlled by the motor driver 209. The ADF motor 207 that drives the automatic document feeder unit (not shown) included in the automatic document scanning unit 200 is controlled by the motor driver 209. The operation display unit 211 consists of an operation panel 300 (Figure 1).

[0022] The host computer 214, located outside the recording device 100, has a printer driver 2141 installed for communicating with the recording device 100 by collecting recording information such as the recorded image and recording image quality when a recording operation is commanded by the user. The MPU 201 exchanges recorded images and other information with the host computer 214 via the I / F unit 213. The transport motor 205 is driven by servo control using position information and speed information obtained from the transport motor encoder 222. Servo control is implemented by the MPU 201 executing a program stored in the ROM 202. The servo control process is repeated every servo period ΔT. The MPU 201 also has a PWM signal generation unit that generates PWM signals, and the PWM signal output from the MPU 201 to the motor driver 209 is represented by a duty cycle (ratio of high level to low level, ratio of on to off). The range of this duty cycle is from 0% to 100%. The larger the duty cycle, the greater the voltage and power supplied to the motor.

[0023] <Recording operation> Figure 6 shows the control flow of the recording operation in this embodiment. Below, we will describe a case in which the temperature difference between the temperature before heating and the temperature after heating is suppressed to within a certain value when the transport motor 205 heats up.

[0024] In step S601, the MPU201 performs the feeding operation of the recording medium. Hereafter, "step S~" will be abbreviated as "S~".

[0025] In S602, the MPU201 determines whether the motor temperature rise flag is on. If the result of this step is YES (flag is on), the process proceeds to S603. On the other hand, if the result of this step is NO (flag is off), the process proceeds to S605.

[0026] In S603, the MPU201 performs a pre-recording wait operation. This pre-recording wait operation is performed to reduce the motor temperature. After the pre-recording wait operation is completed, the process proceeds to S604.

[0027] In S604, the MPU201 switches the recording device 100 to the second recording mode.

[0028] In S605, the MPU201 switches the recording device 100 to the first recording mode. In both the first recording mode in S605 and the second recording mode in S604, a recording operation for one band is performed by driving the carriage motor 204, and a transport operation is performed by driving the transport motor 205.

[0029] The operation of the first recording mode and the second recording mode will be explained below using Figure 7. Figure 7 shows the rotational speed and start / end timing of the carriage motor 204, and the rotational speed and start / end timing of the transport motor 205.

[0030] Figure 7(a) shows the first recording mode. The carriage motor 204 and the transport motor 205 are controlled to prevent unnecessary waiting time in order to improve the productivity of the recording operation. That is, the recording head 4 performs ejection even while the carriage 7 is accelerating or decelerating, but it does not perform ejection immediately after the start of operation or immediately before stopping because the scanning speed of the carriage 7 is not stable. This is represented as the "ejection region" in Figure 7(a). Since a normal image cannot be recorded if the paper moves during the ejection operation, the transport motor 205 starts driving while the carriage 7 is decelerating, almost simultaneously with the completion of ejection. In addition, the time from the start of carriage 7 operation to the start of ejection is calculated, and the start of driving of the carriage motor 204 is controlled so that the ejection of the recording head 4 starts almost simultaneously with the stop of operation of the transport motor 205.

[0031] Figure 7(b) shows the second recording mode. The second recording mode is the operation when the motor heats up. As shown by T1 in the figure, the motor temperature is reduced by introducing a predetermined wait time. Here, we have described a case in which two recording modes, the first recording mode and the second recording mode, are used, but it is also possible to set two or more temperature rise detection thresholds and perform stepwise control, such as extending the wait time when a higher level of temperature rise is detected. As described above, in this embodiment, the drive pattern of the transport motor is changed according to the state of the motor (specifically, whether or not the motor is in a heated state).

[0032] Returning to the explanation of Figure 6, in S606, the MPU201 determines whether recording for one page has finished. If the result of this step is YES, proceed to S607. On the other hand, if the result of this step is NO, return to S602.

[0033] In S607, the MPU201 performs the paper ejection operation for the recording medium after one page of recording has been completed.

[0034] In S608, the MPU201 performs a temperature rise detection operation. In this step, the transport motor 205 is driven for a short time, and it is determined whether the temperature has risen according to the flow described later (Figure 8). If it is determined that the temperature has risen, the temperature rise flag is turned on. At this timing, the transport of the recording medium has finished, and there are no factors of variation due to the thickness or transport position of the recording medium, so stable detection is possible. However, the timing of the temperature rise detection is not limited to this. It is possible to determine whether the temperature has risen or not at any of the timings in which the transport motor 205 is driven, such as the feeding operation in S601, the line break operation during recording in S605, or the paper ejection operation in S607.

[0035] Furthermore, the timing of the wait operation is not limited to what is described here. Since it is a requirement to lengthen the non-operating time of the transport motor 205 when the temperature rises, for example, the wait operation may occur before S601, or before or after S607. In this embodiment, the wait operation is performed when the temperature rises (S602YES→S603), but the requirement is to suppress the temperature rise of the motor. Therefore, in the feeding operation of S601, the line break operation during recording of S605, and the paper ejection operation of S607, the current value flowing to the motor may be reduced by lowering the motor's acceleration and drive speed, thereby making it more difficult for the motor to overheat.

[0036] In S609, the MPU201 determines if there is another page to record. If the result of this step is YES, the process returns to S601. On the other hand, if the result of this step is NO, the process proceeds to S610.

[0037] In S610, the MPU201 puts the recording device 100 into standby mode. In standby mode, it waits and checks if it receives an instruction from the host computer 214 to start recording. For example, if it does not receive an instruction from the host computer 214 to start recording within one minute, it caps the recording head 4 and turns off the motor temperature rise flag. However, if it receives an instruction to start recording within one minute, it does not change the motor temperature rise flag from on to off, but maintains the motor temperature rise flag as on, transitions from standby mode to a state where it can start the control flow shown in Figure 6.

[0038] <Details of the temperature rise detection process> The temperature rise determination operation of S608 will be explained below using Figure 8. Figure 8 shows the detailed processing flow of the temperature rise determination operation. In the process shown in Figure 8, a determination is made as to whether or not to turn on the temperature rise mode. Note that the entity that executes the processing of each step in Figure 8 is the MPU201, but the description of this entity will be omitted below.

[0039] In S801, the count value Toover (labeled as the number of temperature rise judgments in Figure 8) is initialized (i.e., the Toover value is set to zero). This Toover is the count value of the time during motor operation when the PWM value exceeds the temperature rise judgment threshold PWMhot.

[0040] In S802, the PWM threshold (PWMhot) and time threshold (Thot) for determining temperature rise are determined based on the ambient temperature value acquired in advance and stored in RAM203. The method for determining the PWM threshold (PWMhot) and time threshold (Thot) in this step will be described later.

[0041] In S803, it is determined whether the state of the transport motor 205 is within the temperature rise determination region. If the result of this step is YES, the process proceeds to S804. On the other hand, if the result of this step is NO, the series of processes is terminated. The temperature rise determination region refers to a predetermined section of servo control in which temperature rise determination is performed. For example, as shown by the dashed line in Figure 9, the temperature rise determination region is set to "during acceleration control," etc. This region can be arbitrarily set according to the timing at which the determination contributes to high-precision determination. During acceleration, differences due to load tend to be large, but variability is also easily picked up. During constant speed, it is stable, but the absolute value is low, so it is necessary to set the threshold with high precision.

[0042] In S804, it is determined whether the PWM value > PWM threshold (PWMhot, for example, 90%). If the result of this step is YES, the process proceeds to S805. On the other hand, if the result of this step is NO, the process returns to S803. PWMhot can be set to an individual value for each motor drive pattern. In this embodiment, there are three print modes (also called motor drive modes) on which the recording device 100 can operate: speed priority mode, standard mode, and image quality priority mode. The recording device 100 is equipped with a speed profile corresponding to each of these three motor drive modes. Furthermore, each speed profile is equipped with different speed information to enable appropriate acceleration. A threshold can be set in association with the print mode (motor drive mode).

[0043] In S805, the value of Toover is incremented (i.e., 1 is added). Note that the value added in this step is not limited to 1. In other words, as shown in Figure 8, the processes from S803 to S806 are executed repeatedly, and this repetition is performed at predetermined time intervals. The value added in this step should be appropriately set according to the time required to execute the process once.

[0044] In S806, it is determined whether Toover > Thot. If the result of this step is YES, the process proceeds to S807. On the other hand, if the result of this step is NO, the process returns to S803. The time threshold Thot is a threshold used to evaluate the time that the PWM value is exceeded. When the count value exceeds the threshold, it can be assumed that the motor temperature is rising. Conversely, when the count value is small, it can be assumed that the time that the PWM value exceeds the threshold is short, and the motor temperature is not rising. In this implementation, the value of Thot can be associated with each printing mode (motor drive mode), just like PWMhot. Alternatively, in another embodiment, the same value may be used regardless of the printing mode.

[0045] In S807, turn on the motor temperature rise flag.

[0046] Figure 9 shows an example of temperature rise detection, with time on the horizontal axis and PWM and velocity on the vertical axis. In the temperature rise detection region shown in the figure (during acceleration in this example), the time during which the PWM exceeds the PWM threshold (PWMhot), known as Toover, is counted. During acceleration, the required torque is large, so a peak in the PWM is observed as shown in the figure. In this example, temperature rise detection is performed based on the magnitude of this peak value.

[0047] <Method for determining the threshold> The following describes the determination method in S802, specifically the method for determining the PWM threshold (PWMhot) and time threshold (Thot) used to determine temperature rise based on the ambient temperature, using Figure 10. When the ambient temperature changes, the winding resistance and magnetic force of the DC motor change. Also, because the load on the recording device 100 itself fluctuates, the magnitude of the PWM signal may change even at the same motor temperature. Figure 10 shows how the PWM signal is output when the motor temperature is at each ambient temperature. From Figure 10, it can be seen that even at the same motor temperature, the output PWM value is different. For this reason, if PWMhot is a uniform value that does not depend on the ambient temperature, it is not possible to determine that the motor is in a temperature rise state at a constant motor temperature. Therefore, in this embodiment, as shown in Figure 10, there are three types of PWM thresholds (PWMhot). Specifically, there are thresholds for low temperature environments, medium temperature environments, and high temperature environments. Here, the low-temperature environment setting is applied when the ambient temperature is below 18 degrees Celsius, the medium-temperature environment setting is applied when the ambient temperature is between 18 degrees Celsius and 28 degrees Celsius, and the high-temperature environment setting is applied when the ambient temperature is 28 degrees Celsius or higher. The three types of PWM thresholds (PWMhot) introduced here are pre-stored in ROM202, and in S802 (Figure 8) mentioned above, the PWM threshold to be applied is determined by selecting one of these three types of PWM thresholds. As explained above, in this embodiment, the PWM threshold selected according to the temperature is applied from at least two or more pre-set thresholds.

[0048] Although this section describes changing the PWM threshold (PWMhot), the time threshold (Thot) can also be changed in a similar manner according to the ambient temperature. The ambient temperature is detected by a temperature sensor mounted on the carriage board 71 (see Figures 4(a) and 4(b)) inside the recording device 100. Because the recording device 100 contains heat sources such as the power supply 13 (see Figure 2) and the recording head 4, continuous operation may cause a discrepancy between the temperature of the load-generating parts of the main unit (such as the bearings of each roller and gear) and the permanent magnet of the DC motor that are the intended targets. Therefore, temperature detection by the temperature sensor is performed from the time the recording device is powered on and the temperature sensor is energized until the first feed operation is performed. If the recording device 100 remains powered on and the temperature sensor is continuously detectable, detection is performed after a certain amount of time has elapsed since the printing operation (for example, 3 hours).

[0049] <Effects of this embodiment> As described above, in this embodiment, motor temperature rise is determined based on a PWM threshold that changes according to the ambient temperature. This makes it possible to accurately detect motor temperature rise for users in any temperature environment. Therefore, even for users in such temperature environments, it is possible to perform transport and recording operations while maintaining uniform productivity.

[0050] [Second Embodiment] In the first embodiment, temperature rise detection of a transport motor 205 that drives the transport roller 1 and the feed roller 31 was described, but this disclosure is also applicable to motors other than transport motors. In this embodiment, the case in which temperature rise detection is applied to a carriage motor 204 will be described.

[0051] The timing of temperature rise detection, and the operation and processing when temperature rise is detected, are the same as in the first embodiment (see Figures 6 and 7). Similar to the transport motor 205 described in the first embodiment, after the recording or paper ejection operation is completed, a temperature rise detection operation is performed as in S608. If temperature rise is detected, a wait operation is performed to lower the temperature of the heated motor, as shown in Figure 7(b). In the first embodiment, as explained using Figure 7, it was stated that the purpose was to lower the temperature of the transport motor, but since the temperature of the carriage motor 204 can also be expected to decrease with the exact same operation, the operation after temperature rise detection is the same as in the first embodiment. However, the wait time may be set appropriately for each motor so that a temperature decrease can be expected in each motor.

[0052] Furthermore, in this embodiment, when changing the motor's acceleration or temperature, the changes are made to those of the carriage motor 204, not the transport motor 205. The processing flow for temperature rise determination is exactly the same as that for the transport motor 205 described in the first embodiment (see Figures 8 to 10). Two thresholds, a PWM threshold and a time threshold, are changed according to the ambient temperature. Since the load conditions differ for each motor, the PWM threshold, the time threshold, and the temperature threshold used when changing them are set individually for each motor. However, if the load conditions, acceleration, and speed are similar, they may be shared between the carriage motor 204 and the transport motor 205.

[0053] This disclosure can also be implemented by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be implemented by a circuit (e.g., an ASIC) that implements one or more functions.

[0054] [Technical Features of This Disclosure] This disclosure includes the following components:

[0055] (Configuration 1) A transport device comprising: a transport roller for transporting a recording medium; a transport motor that generates a driving force for driving the transport roller; an encoder for detecting the rotation of the transport motor; a control unit that performs servo control of the transport motor based on an encoder signal output by the encoder, the control unit having a signal generation unit that generates a PWM signal; a motor driver that controls the transport motor based on the PWM signal output by the control unit; and a detection means for detecting the ambient temperature, wherein the control unit performs a temperature rise determination operation that determines whether the PWM value of the PWM signal is greater than a PWM threshold determined according to the ambient temperature, and changes the drive pattern of the transport motor when it is determined that the temperature has risen. (Configuration 2) The conveying device according to Configuration 1, characterized in that the control unit performs the temperature rise determination operation and, when it determines that the temperature has risen, changes the timing at which the conveying motor is started to drive. (Configuration 3) The transport device according to Configuration 1 or 2, characterized in that, in the temperature rise determination operation, the control unit counts the time during which the PWM value is greater than the PWM threshold, determines whether the number of temperature rise determinations, which is the count value of the count, is greater than a predetermined time threshold, and determines that the temperature has risen if it is determined to be greater. (Configuration 4) The transport device according to any one of Configurations 1 to 3, characterized in that the control unit performs the temperature rise determination operation before performing the feeding operation in which the recording medium to be recorded is fed by the feeding means. (Configuration 5) The conveying device according to any one of Configurations 1 to 4, characterized in that the timing of the detection by the detection means is between the time the detection means becomes available and the time the first feeding operation is performed. (Configuration 6) The transport device according to any one of Configurations 1 to 5, characterized in that the control unit performs a paper ejection operation for ejecting a recording medium after recording has been completed, and then performs the temperature rise determination operation. (Configuration 7) The transport device according to any one of Configurations 1 to 6, characterized in that the control unit determines the PWM threshold and the time threshold based on the ambient temperature obtained by the detection means. (Configuration 8) The transport device according to any one of Configurations 1 to 7, characterized in that the control unit selects from at least two or more preset thresholds when determining the PWM threshold. (Configuration 9) A recording device comprising a transport device according to any one of Configurations 1 to 8, a recording head having a discharge port for discharging liquid, a carriage on which the recording head is mounted, a carriage unit including a carriage substrate, and a carriage motor that generates a driving force for scanning the carriage, wherein the detection means is a temperature sensor mounted on the carriage substrate. (Configuration 10) The recording device according to Configuration 9, characterized in that, in the temperature rise determination operation, it operates in a first recording mode when it is determined that there is no temperature rise, and operates in a second recording mode when it is determined that there is a temperature rise. (Configuration 11) The recording device according to Configuration 9 or 10, characterized in that in the second recording mode, a wait time is provided for the transport motor to be driven, and the transport motor is driven after the carriage motor has finished driving. (Configuration 12) A recording device according to any one of Configurations 9 to 11, characterized in that, when a temperature rise is determined in the temperature rise determination operation, the control unit reduces the acceleration or drive speed of the transport motor. (Configuration 13) A recording device comprising: a carriage on which a recording head is mounted; a carriage motor that generates a driving force for scanning the carriage; an encoder that detects the rotation of the carriage motor; a control unit that performs servo control of the carriage motor based on an encoder signal output by the encoder, the control unit having a signal generation unit that generates a PWM signal; a motor driver that controls the carriage motor based on the PWM signal output by the control unit; and a detection means for detecting the ambient temperature, wherein the control unit performs a temperature rise determination operation that determines whether the PWM value of the PWM signal is greater than a PWM threshold determined according to the ambient temperature, and changes the drive pattern of the carriage motor when it is determined that the temperature has risen. (Configuration 14) The recording device according to Configuration 13, characterized in that, when a temperature rise is determined in the temperature rise determination operation, the control unit reduces the acceleration or drive speed of the carriage motor. (Control method for transport device) A control method for a transport device comprising: a transport roller for transporting a recording medium; a transport motor that generates a driving force for driving the transport roller; an encoder for detecting the rotation of the transport motor; a control unit that performs servo control of the transport motor based on an encoder signal output by the encoder, the control unit having a signal generation unit that generates a PWM signal; a motor driver that controls the transport motor based on the PWM signal output by the control unit; and a detection means for detecting the ambient temperature, the control method comprising an execution step in which the control unit performs a temperature rise determination operation that includes determining whether or not the PWM value of the PWM signal is greater than a PWM threshold determined according to the ambient temperature, and if a temperature rise is determined, the execution step of changing the drive pattern of the transport motor. A program for causing a computer to execute a control method for a recording device, comprising: a transport roller for transporting a recording medium; a transport motor that generates a driving force to drive the transport roller; an encoder for detecting the rotation of the transport motor; a control unit that performs servo control of the transport motor based on an encoder signal output by the encoder, the control unit having a signal generation unit that generates a PWM signal; a motor driver that controls the transport motor based on the PWM signal output by the control unit; and a detection means for detecting the ambient temperature, wherein the control unit performs a temperature rise determination operation which involves determining whether the PWM value of the PWM signal is greater than a PWM threshold determined according to the ambient temperature, and the execution step of changing the drive pattern of the transport motor when a temperature rise is determined. [Explanation of Symbols]

[0056] 1 Conveyor roller 100 Recording device 201 MPU 209 Motor Driver 205 Transport Motor 222 Carrier Motor Encoder

Claims

1. A transport roller for transporting the recording medium, A conveying motor that generates a driving force to drive the conveying roller, An encoder for detecting the rotation of the transport motor, A control unit that performs servo control of the transport motor based on the encoder signal output by the encoder, the control unit having a signal generation unit that generates a PWM signal, A motor driver controls the transport motor based on the PWM signal output by the control unit, A detection means for detecting the outside temperature, It has, The control unit performs a temperature rise determination operation that determines whether the PWM value of the PWM signal is greater than a PWM threshold determined according to the ambient temperature, and if it determines that the temperature has risen, it changes the drive pattern of the transport motor. A conveying device characterized by the following features.

2. The control unit performs the temperature rise determination operation, and if it determines that the temperature has risen, it changes the timing at which it starts driving the transport motor. The conveying device according to feature 1.

3. The control unit, in the temperature rise determination operation, counts the time during which the PWM value is greater than the PWM threshold, determines whether the number of temperature rise determinations, which is the count value of the count, is greater than a predetermined time threshold, and determines that temperature rise has occurred if it is determined to be greater. The conveying device according to feature 1 or 2.

4. The control unit performs the temperature rise determination operation before performing the feeding operation to feed the recording medium to be recorded using the feeding means. The conveying device according to feature 1 or 2.

5. The timing for detecting the outside temperature using the detection means is from the time the detection means becomes available until the first feeding operation is performed. The conveying device according to feature 4.

6. The control unit performs a paper ejection operation to eject the recording medium after recording is complete, and then performs the temperature rise determination operation. The conveying device according to feature 4.

7. The control unit determines the PWM threshold and the time threshold based on the ambient temperature obtained by the detection means. The conveying device according to feature 3.

8. When determining the PWM threshold, the control unit selects from at least two or more preset thresholds. The conveying device according to feature 7.

9. A conveying device according to claim 1 or 2, A recording head having an outlet for discharging liquid, A carriage unit including a carriage on which the recording head is mounted and a carriage substrate, A carriage motor that generates a driving force for scanning the carriage, It has, The detection means is a temperature sensor mounted on the carriage substrate. A recording device characterized by the following features.

10. In the aforementioned temperature rise determination operation, if it is determined that there is no temperature rise, it operates in the first recording mode, and if it is determined that there is a temperature rise, it operates in the second recording mode. The recording device according to feature 9.

11. In the second recording mode, a waiting time is provided for the transport motor to start, and the transport motor starts after the carriage motor has finished running. The recording device according to feature 10.

12. If a temperature rise is detected during the temperature rise determination operation, the control unit reduces the acceleration or drive speed of the transport motor. The recording device according to feature 11.

13. A carriage equipped with a recording head, A carriage motor that generates a driving force for scanning the carriage, An encoder for detecting the rotation of the carriage motor, A control unit that performs servo control of the carriage motor based on the encoder signal output by the encoder, the control unit having a signal generation unit that generates a PWM signal, A motor driver controls the carriage motor based on the PWM signal output by the control unit, A detection means for detecting the outside temperature, It has, The control unit performs a temperature rise determination operation that determines whether the PWM value of the PWM signal is greater than a PWM threshold determined according to the ambient temperature, and if it determines that the temperature has risen, it changes the drive pattern of the carriage motor. A recording device characterized by the following features.

14. If the temperature rise is determined in the temperature rise determination operation, the control unit reduces the acceleration or drive speed of the carriage motor. The recording device according to feature 13.

15. A transport roller for transporting the recording medium, A conveying motor that generates a driving force to drive the conveying roller, An encoder for detecting the rotation of the transport motor, A control unit that performs servo control of the transport motor based on the encoder signal output by the encoder, the control unit having a signal generation unit that generates a PWM signal, A motor driver controls the transport motor based on the PWM signal output by the control unit, A detection means for detecting the outside temperature, A control method for a conveying device having, The control unit performs an execution step of determining whether the PWM value of the PWM signal is greater than a PWM threshold determined according to the ambient temperature, and if it determines that the temperature has risen, the execution step of changing the drive pattern of the transport motor. A control method characterized by the following:

16. A program for causing a computer to execute the control method for the transport device described in claim 15.

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