JP4612867B2 - Power supply circuit, motor driver circuit, electronic device, and recording apparatus - Google Patents

Description

  The present invention relates to a motor driver circuit and a control method for the circuit, and more specifically, a drive circuit that drives at least one motor, a plurality of DC / DC converters, and an abnormality in the output of the DC / DC converter. The present invention relates to control of a motor driver circuit including a protection circuit that stops the DC / DC converter when detected, and to an electronic device.

  2. Description of the Related Art In recent years, an ink jet recording apparatus is generally configured to have a plurality of motors corresponding to operations such as scanning of a recording head, feeding of recording paper, transport of recording paper during recording, and maintenance of the recording head. It is coming.

  Increasingly, motor drivers used in electronic devices such as ink jet recording apparatuses are provided with a multi-axis drive circuit capable of driving a plurality of motors and formed as one IC.

  Conventionally, DC / DC converter circuits have been provided with overcurrent detection means, overvoltage detection means, and internal temperature detection means as detection means for detecting abnormalities and malfunctions. The overcurrent detection means detects that the current flowing through the MOS transistor of the DC / DC converter exceeds a predetermined value (Patent Document 1).

  There are two major cases of overcurrent. One is when an abnormality such as a short circuit occurs, and the other is when the load current of the DC / DC converter is overloaded.

  The overvoltage detection means detects that the output voltage of the DC / DC converter has fluctuated about 30%.

  Further, the overcurrent detection means of the DC / DC converter is configured to detect an overcurrent when power (VBUS) is supplied to a device connected via the USB interface.

It is also known to output signals from a plurality of DC / DC converters to the CPU (Patent Document 2) and to perform initial setting from the CPU to the motor driver by serial transfer (Patent Document 3).
Japanese Patent Laid-Open No. 9-037347 JP 11-33001 A JP 2005-65486 A

  As described above, the motor driver includes a multi-axis drive circuit capable of driving a plurality of motors and is formed as one IC. However, a regulator, a DC / DC circuit, a reset circuit, and the like are further incorporated into one IC. Assume that (integrated circuit) is formed.

  When the above-described overcurrent detection means (or overvoltage detection means) detects, it performs control to turn off the output stage of the DC / DC converter, assuming that an abnormality occurs in the IC (integrated circuit) including the overcurrent detection means. The motor drive circuit is also controlled to stop.

  When a reset function is built in, a reset signal for asserting an IC supplied with power from the DC / DC converter of the motor driver is asserted.

  In such a configuration, the overcurrent protection by the overcurrent detection of the DC / DC converter, the overvoltage protection by the overvoltage detection, and the overheat protection of the IC by the IC internal temperature detection means are activated, and any DC / DC converter or motor drive circuit is activated. If the power is input to the motor driver, the DC / DC converter and the motor drive circuit will recover unless the power is turned on again after the power supply voltage drops below the specified voltage. do not do.

  Here, when the DC / DC converter built in the motor driver supplies power to the CPU, once the power of the motor driver is turned off, the power of the CPU is also turned off.

  That is, when any protection circuit is activated, the CPU power is also turned off, so that the CPU cannot recognize which protection circuit is activated.

  The present invention has been made in view of the above situation, and in a motor driver circuit incorporating a plurality of DC / DC converters, can notify that a specific DC / DC converter has been stopped by a protection circuit, and It is an object of the present invention to enable the return process of the converter.

A power supply circuit according to an aspect of the present invention that achieves the above object is a power supply circuit including a plurality of DC / DC converters for supplying power to a plurality of power supply destinations including an external circuit , A stop circuit that stops the DC / DC converter when an abnormality is detected in the output of the DC / DC converter, and a specific DC / DC converter among the plurality of DC / DC converters is stopped by the stop circuit Occasionally, an output circuit for outputting a first signal to the external circuit, when the second signal from the circuit of the external is input, a return means for returning said specific DC / DC converter, wherein A communication means for communicating with an external circuit, a reset circuit for outputting a third signal for resetting the external circuit, and a circuit from the external circuit via the communication means. When the respective DC / DC converters are stopped by the stop circuit, the control for individually setting whether or not to stop other DC / DC converters and the third signal are output. Control means for performing control for individually setting whether or not .

The power supply circuit as one aspect of the present invention that achieves the above object is also a power supply circuit including a plurality of DC / DC converters for supplying power to a plurality of power supply destinations including an external circuit, A stop circuit that stops the DC / DC converter when an abnormality is detected in the output of the DC / DC converter, and a specific DC / DC converter among the plurality of DC / DC converters is stopped by the stop circuit. An output circuit for outputting a first signal to the external circuit, and a return means for returning the specific DC / DC converter when a second signal is input from the external circuit; Communication means for communicating with the external circuit, and each DC / DC converter by the stop circuit according to a setting from the external circuit via the communication means Control means for individually setting whether or not to stop other DC / DC converters when the DC / DC converter is stopped, and a DC / DC converter other than the specific DC / DC converter includes the power supply circuit. It is good also as supplying electric power with respect to the said external circuit which controls the apparatus carrying .

As another aspect of the present invention for achieving the above object, a motor driver circuit comprising the power supply device having the above configuration and a drive circuit for driving at least one motor, and the power supply having the above configuration An electronic apparatus including a circuit, a driver circuit thereof, a scanning device that scans the recording head with respect to the recording medium, and a recording apparatus that includes a conveying unit that conveys the recording medium. The recording apparatus may further include a carriage motor that is a driving source of the scanning unit and a conveyance motor that is a driving source of the conveying unit.

  According to the present invention, it is possible to notify the outside that a specific DC / DC converter among the plurality of DC / DC converters is stopped by the protection circuit by the first signal, and by inputting the second signal from the outside. The specific DC / DC converter can be restored.

  Therefore, the CPU of the device on which the motor driver circuit is mounted can be notified that the specific DC / DC converter has been stopped by the protection circuit, and the motor driver circuit itself can be output by outputting the second signal from the CPU. The DC / DC converter that has been stopped can be restored without turning off the power.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the components described in the following embodiments are merely examples, and are not intended to limit the scope of the present invention only to them.

  In the embodiment described below, a motor driver of a recording apparatus using a recording head according to an ink jet method will be described as an example.

<Description of Inkjet Recording Device (FIG. 2)>
FIG. 2 is an external perspective view showing an outline of the configuration of a typical ink jet recording apparatus in which the motor driver according to the present invention is used.

  As shown in FIG. 2, an ink jet recording apparatus (hereinafter referred to as a recording apparatus) transmits a driving force generated by a carriage motor M1 to a carriage 2 on which a recording head 3 that performs recording by discharging ink according to an ink jet system is mounted. 4, the carriage 2 is reciprocated in the direction of arrow A, and for example, a recording medium P such as recording paper is fed through a paper feeding mechanism 5 and conveyed to a recording position. Recording is performed by ejecting ink onto the recording medium P.

  Further, in order to maintain the state of the recording head 3 satisfactorily, the carriage 2 is moved to the position of the recovery device 10 and the ejection recovery process of the recording head 3 is intermittently performed.

  In addition to mounting the recording head 3 on the carriage 2 of the recording apparatus 1, an ink cartridge 6 for storing ink to be supplied to the recording head 3 is mounted. The ink cartridge 6 is detachable from the carriage 2.

  The recording apparatus 1 shown in FIG. 2 can perform color recording. For this reason, the carriage 2 has four inks containing magenta (M), cyan (C), yellow (Y), and black (K) inks, respectively. An ink cartridge is installed. These four ink cartridges can be attached and detached independently.

  Now, the carriage 2 and the recording head 3 can achieve and maintain a required electrical connection by properly contacting the joint surfaces of both members. The recording head 3 applies energy according to a recording signal to selectively eject ink from a plurality of ejection ports for recording. In particular, the recording head 3 of this embodiment employs an ink jet system that ejects ink using thermal energy, and includes an electrothermal transducer to generate thermal energy, which is applied to the electrothermal transducer. Electric energy is converted into thermal energy, and ink is ejected from the ejection port by utilizing pressure changes caused by bubble growth and contraction caused by film boiling caused by applying the thermal energy to the ink. This electrothermal transducer is provided corresponding to each of the ejection ports, and ink is ejected from the corresponding ejection port by applying a pulse voltage to the corresponding electrothermal transducer in accordance with the recording signal.

  As shown in FIG. 2, the carriage 2 is connected to a part of the driving belt 7 of the transmission mechanism 4 that transmits the driving force of the carriage motor M <b> 1, and slides in the direction of arrow A along the guide shaft 13. It is guided and supported freely. Accordingly, the carriage 2 reciprocates along the guide shaft 13 by forward and reverse rotations of the carriage motor M1. A scale 8 is provided for indicating the absolute position of the carriage 2 along the direction of movement of the carriage 2 (the direction of arrow A). In this embodiment, the scale 8 uses a transparent PET film with black bars printed at a necessary pitch, one of which is fixed to the chassis 9 and the other is supported by a leaf spring (not shown). Yes.

  Further, the recording apparatus 1 is provided with a platen (not shown) facing the discharge port surface where the discharge port (not shown) of the recording head 3 is formed, and the recording head 3 is driven by the driving force of the carriage motor M1. At the same time as the carriage 2 loaded with is reciprocated, recording is performed over the entire width of the recording medium P conveyed on the platen by giving a recording signal to the recording head 3 and discharging ink.

  Further, in FIG. 2, 14 is a transport roller driven by a transport motor M2 to transport the recording medium P, 15 is a pinch roller that abuts the recording medium P against the transport roller 14 by a spring (not shown), and 16 is a pinch. A pinch roller holder 17 that rotatably supports the roller 15 is a conveyance roller gear fixed to one end of the conveyance roller 14. Then, the transport roller 14 is driven by the rotation of the transport motor M2 transmitted to the transport roller gear 17 through an intermediate gear (not shown).

  Further, reference numeral 20 denotes a discharge roller for discharging the recording medium P on which an image is formed by the recording head 3 to the outside of the recording apparatus, and is driven by transmitting the rotation of the transport motor M2. . The discharge roller 20 abuts on a spur roller (not shown) that presses the recording medium P by a spring (not shown). Reference numeral 22 denotes a spur holder that rotatably supports the spur roller.

  Further, as shown in FIG. 2, the recording apparatus includes a desired position (for example, a home position) outside the range of reciprocating motion (outside the recording area) for the recording operation of the carriage 2 on which the recording head 3 is mounted. A recovery device 10 for recovering the ejection failure of the recording head 3 is disposed at a position corresponding to (1).

  The recovery device 10 includes a capping mechanism 11 for capping the ejection port surface of the recording head 3 and a wiping mechanism 12 for cleaning the ejection port surface of the recording head 3, and interlocks with the capping of the ejection port surface by the capping mechanism 11. Ink recovery such as forcibly discharging ink from the discharge port by suction means (suction pump or the like) in the recovery device, thereby removing ink or bubbles having increased viscosity in the ink flow path of the recording head 3 Process.

  Further, when the recording head 3 is not in operation or the like, the ejection port surface of the recording head 3 is capped by the capping mechanism 11 to protect the recording head 3 and to prevent ink evaporation and drying. On the other hand, the wiping mechanism 12 is disposed in the vicinity of the capping mechanism 11 and wipes ink droplets adhering to the ejection port surface of the recording head 3.

  The capping mechanism 11 and the wiping mechanism 12 can keep the ink ejection state of the recording head 3 normal.

<Control Configuration of Inkjet Recording Apparatus (FIG. 3)>
FIG. 3 is a block diagram showing a control configuration of the recording apparatus shown in FIG.

  As shown in FIG. 3, the controller 600 includes an MPU 601, a program corresponding to a control sequence to be described later, a required table, a ROM 602 storing other fixed data, a control of the carriage motor M1, a control of the transport motor M2, and a recording. A special purpose integrated circuit (ASIC) 603 that generates a control signal for controlling the head 3, and a RAM 604, an MPU 601, an ASIC 603, and a RAM 604, which are provided with image data development areas and program execution areas A system bus 605 for transferring data, and an A / D converter 606 for inputting analog signals from the sensor group described below, A / D converting them, and supplying digital signals to the MPU 601 and the like.

  In FIG. 3, reference numeral 610 denotes a computer (or a reader for image reading, a digital camera, or the like) serving as a supply source of image data, and is collectively referred to as a host device. Image data, commands, status signals, and the like are transmitted and received between the host apparatus 610 and the recording apparatus 1 via an interface (I / F) 611.

  Further, reference numeral 620 denotes a switch group, which instructs activation of a power switch 621, a print switch 622 for instructing printing start, and a process (recovery process) for maintaining the ink ejection performance of the recording head 3 in a good state. For example, a recovery switch 623 for receiving a command input from the operator. Reference numeral 630 denotes a position sensor 631 such as a photocoupler for detecting the home position h, a temperature sensor 632 provided at an appropriate location of the recording apparatus for detecting the environmental temperature, and the like. It is a sensor group.

  Further, 640 is a carriage motor driver that drives a carriage motor M1 for reciprocating scanning of the carriage 2 in the direction of arrow A, and 642 is a conveyance motor driver that drives a conveyance motor M2 for conveying the recording medium P. Although only two motors and motor drivers are shown here, in reality, motors for recovery processing and paper feed / discharge are used in addition to these motors. A motor driver is also provided accordingly. The carriage motor driver 640 and the conveyance motor driver 642 are included in a motor driver circuit 100 shown in FIG.

  The ASIC 603 transfers drive data (DATA) of the printing element (ejection heater) to the printing head while directly accessing the storage area of the RAM 602 during printing scanning by the printing head 3.

<Motor driver>
FIG. 1 is a block diagram illustrating a configuration example of an embodiment of a motor driver circuit according to the present invention used in the electronic apparatus (recording apparatus) described above. In addition, the motor driver circuit of this embodiment shall be integrally formed as one IC.

  In the figure, reference numeral 100 denotes a motor driver circuit of this embodiment. Reference numerals 101 to 104 denote drive circuits for driving the motor. Reference numerals 105 to 108 denote motors driven by the motor drive circuits 101 to 104. The motor may be a DC motor or a stepping motor. For example, the carriage motor driver 640 and the conveyance motor driver 642 illustrated in FIG. 3 correspond to any of 101 to 104.

  Reference numerals 109 to 111 denote DC / DC converters (voltage generation means). The motor driver circuit 100 according to the present embodiment includes a three-channel DC / DC converter of A, B, and C. An electric power d of 18 V (volt) output from a power supply circuit (not shown) is input, and the three DC / DC converters convert each into a desired voltage and supply power (arrows a, b, c).

  The outputs of the DC / DC converters A (109) and B (110) are supplied as power to a CPU or ASIC, or a system IC or LSI (120; hereinafter simply referred to as a CPU) that is an integrated one-chip IC. Is done. In this embodiment, 3.3 V for external ports and 1.5 V for internal logic are supplied from converters A and B, respectively. In this embodiment, the DC / DC converter C (111) is connected to the power supply unit (VBUS) of the USB interface (121) and can supply 5V power to the connected USB device. Yes.

  Reference numeral 112 denotes overcurrent detection means that detects that a current exceeding a predetermined value has flowed through the MOS transistor of the DC / DC converter. There are two purposes for overcurrent detection. One is detection of an abnormality such as a short circuit, and the other is detection of a state in which the load of the output destination of the DC / DC converter becomes very large (overload state). is there. 113 is an overvoltage detection means for detecting that the output voltage of the DC / DC converter has fluctuated by about 30%. Reference numeral 114 denotes chip temperature detection means for detecting the temperature inside the IC. Reference numeral 115 denotes a reset circuit, which asserts a reset signal (RESETX) for about 100 ms after the activation of the DC / DC converter and resets the external circuit (CPU & ASIC 120). Thereby, the recording apparatus is brought into a stopped state.

  The motor driver circuit 100 of this embodiment is controlled by the CPU 120 by serial communication. As shown in FIG. 1, the CPU 120 performs serial communication with three control signals Clk, Data, and Stb.

  Further, the CPU 120 can determine whether the operation mode of the motor driver circuit 100 is the low power consumption mode or the normal mode according to the state (high / low) of the illustrated signal line Sleep. When the recording apparatus does not operate and shifts to a standby state, the motor driver circuit 100 also shifts from the normal mode to the low power consumption mode. The signal line MD_OUT is a signal line for monitoring and outputting an internal signal of the motor driver circuit 100. For example, when the overcurrent protection of the A channel (109) of the DC / DC converter is activated, the MD_OUT signal is set to be low asserted, and the control circuit such as the CPU 120 is notified by the MD_OUT signal. Selection of which internal signal is output to the MD_OUT terminal is performed by serial communication via three signal lines of Clk (clock signal), Data (data signal), and Stb (strobe signal). For example, 16-bit serial data is transmitted using the Clk signal and the Stb signal through the Data signal line.

  As described in the section of the problem to be solved by the above invention, when the DC / DC converter built in the motor driver circuit 100 supplies power to the CPU, the motor driver circuit 100 is temporarily turned on. If turned off, the power of the CPU is also turned off. That is, there arises a problem that the CPU cannot detect that any protection circuit has been activated.

  In the present embodiment, in order to solve this problem, a protection circuit (stop circuit) 116 that stops the DC / DC converter when overcurrent is detected, overvoltage is detected, and the internal temperature rises, and the DC / DC converter is stopped. The control means 117 includes a signal output means 1171 for informing the CPU of the above and a return means 1172 for returning the stopped DC / DC converter in response to a signal from the CPU. For example, the DC / DC converter is stopped by stopping the switching operation of the MOS transistor. On the other hand, when returning the DC / DC converter (resuming power supply), the switching operation of the stopped MOS transistor is started.

  The control unit 117 further includes a storage unit 1173. The storage unit 1173 stores setting information transmitted from the CPU 120 by serial communication via the above-described three signal lines Clk, Data, and Stb. The setting information stored in the storage means 1173 is that which DC / DC converter of A to C is notified to the CPU 120 by the signal MD_OUT when the protection circuit 116 stops, or any DC / DC converter is detected by the protection circuit. Whether or not to stop other DC / DC converters when stopped. That is, based on the information transmitted from the CPU 120, the DC / DC converter that outputs the signal MD_OUT when stopped is selected. Further, according to the information transmitted from the CPU 120, when the DC / DC converter is stopped by the protection circuit, the other DC / DC converters to be stopped are set individually.

  In this embodiment, when the DC / DC converter C (111) is stopped by the protection circuit, the signal output means 1171 asserts the signal line MD_OUT low and notifies the CPU 120, and the DC / DC converter A or B (109 or 110) is stopped by the protection circuit, it is assumed that the reset circuit 115 stops other DC / DC converters by serial communication from the CPU 120.

  For example, when the DC / DC converter A is stopped by the protection circuit, the DC / DC converter B and the DC / DC converter C are set to stop.

  In this embodiment, the DC / DC converter A and the DC / DC converter B are output to the CPU 120, and when one of the DC / DC converters stops, the CPU 120 cannot operate correctly, so all other The DC / DC converter is stopped.

  In the present embodiment, three DC / DC converters have been described, but the present invention is not limited to three.

  Control for the DC / DC converter in the motor driver circuit 100 of the present embodiment will be described with reference to the flowchart of FIG.

  After the activation, it is determined whether or not the protection circuit 116 is activated at a predetermined interval (step S401). When it is detected that the protection circuit is activated, it is determined whether or not the DC / DC converter stopped by the protection circuit 116 is the DC / DC converter C (111) (step S402). If the stopped DC / DC converter is the DC / DC converter C (111), the signal MD_OUT is asserted low by the signal output means 1171 to notify the CPU 120 of the occurrence of an abnormality such as an overcurrent of the VBUS of the USB interface ( Step S403). The display unit 650 can display that an abnormality has occurred in the DC / DC converter C (111). The display unit 650 can display that an abnormality has occurred in the DC / DC converter C (111). By this display, the user removes the cause of the overcurrent, and operates the switch (not shown) to output Sleep from the CPU 120, for example.

  On the other hand, when it is determined that the stopped DC / DC converter is not the DC / DC converter C (111), the DC / DC converter A or B is stopped. The / DC converter is stopped (step S404) and a reset signal (RESETX) is output to the peripheral circuit (CPU 120).

  After step S403 or S404, the process waits until a return signal (permission signal) is input from the CPU 120 (step S405). There are various methods for returning the stopped DC / DC converter, but in the present embodiment, the sleep signal is also used and is set to be recovered at the rising edge of the sleep.

  The Sleep signal is an input pin of an IC constituting a motor driver circuit, and is originally assigned to set the operation mode of the motor driver to the low power consumption mode if the input level is low. In this embodiment, when at least one or more DC / DC converters are stopped by the protection circuit 116, if the return means 1172 recognizes the rising edge of the Sleep signal, the stopped DC / DC converter is returned. I am doing so.

  As described above, according to the present embodiment, the CPU detects that the DC / DC converter C that supplies power to an external USB device among the plurality of built-in DC / DC converters is stopped by the protection circuit. Can be notified. Further, since the return processing of the DC / DC converter can be executed in accordance with the signal from the CPU, in the motor driver circuit incorporating a plurality of DC / DC converters, the specific DC / DC converter is stopped by the protection circuit. Can be recognized by the CPU, and the converter can be restored.

<Other embodiments>
In the configuration in which each of the motor drive circuits 101 to 104 includes a protection circuit (stop circuit) that detects the motor state and stops the operation, the protection circuit is activated due to, for example, a motor failure. In this case, the motor driving circuit may stop driving the motor and notify the CPU 120 from the motor driver 100 using a signal different from the signal MD_OUT.

  Even in this configuration, even when the motor drive circuit is restored after the cause is removed, a sleep signal may be used. In other words, the sleep signal may be combined with the restoration process of the motor drive circuit and the restoration process of the voltage generation circuit.

  With this configuration, an increase in the number of signal lines for performing communication between the CPU 120 and the motor driver 100 can be suppressed.

  The setting information stored in the storage unit 1173 may be a threshold for the overcurrent detection unit to determine an overcurrent or a threshold for the overvoltage detection unit to determine an overvoltage in addition to the above-described content. .

  Further, the factor for outputting the sleep signal from the CPU 120 is not limited to the operation of the switch by the user.

  In the above description, an example in which the present invention is applied to a serial ink jet recording apparatus has been described. However, the present invention is not limited to this, and the circuit configuration includes a motor driver and a plurality of DC / DC converters. If so, the present invention is not limited to the recording apparatus and can be applied to motor driver circuits of various devices.

  Also, the motor driver circuit has been described as being controlled by a serial communication from a control circuit (control means) such as a CPU. However, if there are no restrictions on the number of signal lines or layout, a plurality of signal lines (parallel transfer) The data may be transferred by

  In the above embodiment, the case where a plurality of DC / DC converters are built in the motor driver circuit has been described as an example. However, the motor driver includes a plurality of power supply circuits such as regulators other than the DC / DC converter. It will be apparent to those skilled in the art that the present invention can be applied even when it is included.

  Note that the present invention can be applied to a system (for example, a copier, a facsimile machine, etc.) consisting of a single device even when applied to a system composed of a plurality of devices (for example, a host computer, interface device, reader, printer, etc.). You may apply.

  Another object of the present invention is to supply a storage medium storing software program codes for implementing the functions of the above-described embodiments to a system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium. Needless to say, this can also be achieved by reading and executing the program code stored in.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.

  As a storage medium for supplying the program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) operating on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.

  Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

  When the present invention is applied to the storage medium, the storage medium stores program codes corresponding to the flowchart described above (shown in FIG. 4).

It is a block diagram which shows the structure of the motor driver which concerns on this invention. It is an external appearance perspective view which shows the outline | summary of a structure of the inkjet recording device as an electronic device using the motor driver of FIG. FIG. 3 is a block diagram illustrating a configuration of a control circuit of the recording apparatus in FIG. 2. It is a control flowchart of the motor driver of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Motor driver 101-104 Motor drive circuit 105-108 Motor 109-111 DC / DC converter 112 Overcurrent detection means 113 Overvoltage detection means 114 Temperature detection means 115 Reset circuit 116 Protection circuit 117 Control means 120 CPU & ASIC
121 USB I / F
1171 Signal output means 1172 Restoration means 1173 Storage means

Claims (11)

A power supply circuit including a plurality of DC / DC converters for supplying power to a plurality of power supply destinations including an external circuit ,
A stop circuit for stopping the DC / DC converter when an abnormality is detected in the output of the DC / DC converter;
An output circuit that outputs a first signal to the external circuit when a specific DC / DC converter among the plurality of DC / DC converters is stopped by the stop circuit;
A return means for returning the specific DC / DC converter when a second signal is input from the external circuit ;
Communication means for communicating with the external circuit;
A reset circuit for outputting a third signal for resetting the external circuit;
Whether to stop other DC / DC converters individually when each DC / DC converter is stopped by the stop circuit according to the setting from the external circuit via the communication means and control of, the third power supply circuit, characterized by a control means of whether or not to output a signal performs a control of setting separately. A power supply circuit including a plurality of DC / DC converters for supplying power to a plurality of power supply destinations including an external circuit ,
A stop circuit for stopping the DC / DC converter when an abnormality is detected in the output of the DC / DC converter;
An output circuit that outputs a first signal to the external circuit when a specific DC / DC converter among the plurality of DC / DC converters is stopped by the stop circuit;
A return means for returning the specific DC / DC converter when a second signal is input from the external circuit;
Communication means for communicating with the external circuit,
Depending on the setting from the external circuit via the communication unit setting, when the respective DC / DC converter by said stop circuit is stopped, whether to stop the other DC / DC converter individually Control means for performing,
The DC / DC converter other than the specific DC / DC converter, the power supply circuit, characterized in that for supplying power to the external circuit for controlling the device the power supply circuit is mounted. Further comprising a reset circuit for outputting a third signal for resetting the circuitry of the external,
Wherein said control means further in accordance with the setting from the external circuit via the communication means, whether or not each of the DC / DC converter by the stop circuit when it is stopped, and outputs the third signal power supply circuit according to claim 2, characterized in that you set individually or. The power supply circuit according to claim 1 or 2 , wherein the stop circuit detects an abnormality based on a threshold value of at least one of an output current and an output voltage of each DC / DC converter. Power according to claim 1, wherein the DC / DC converter other than the specific DC / DC converter, and supplying power to the external circuit for controlling the device the power supply circuit is mounted Supply circuit. The particular DC / DC converter, any one of claims 1 to 5, characterized in that supply power via USB to the device to the power supply circuit is connected to the onboard equipment The power supply circuit described in 1. Power supply circuit according to claim 4, in accordance with the setting from the external circuit via the communication means and can be set to the threshold value. The communication means, the power supply circuit according to claim 1 or 2, characterized in that the serial communication with the external circuit. A motor driver circuit comprising: the power supply circuit according to claim 1; and a drive circuit that drives at least one motor. An electronic apparatus comprising the power supply circuit according to claim 1. And a motor driver circuit of claim 9, scanning means for scanning the recording head relative to a recording medium, a recording apparatus having a conveying means for transporting the recording medium,
A recording apparatus comprising: a carriage motor that is a drive source of the scanning unit; and a conveyance motor that is a drive source of the conveyance unit .

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