JP2018068024A - Power supply device and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer that efficiently stops supply of power.SOLUTION: An ink jet printer 5 comprises a high-voltage circuit 100 that supplies a power supplied from a power supply part 10 having a capacitor 15 to an apparatus 50, and the high-voltage circuit 100 includes a switch part 40 that selectively connects the power supply part 10 and apparatus 50, and a switching control part 30 that detects a voltage value of the power and controls switching of the switch part 40 on the basis of the voltage value. When the voltage value of the power supplied from the capacitor 15 makes a transition from a state where the voltage value exceeds a reference value to a state where the voltage value falls below the reference value, the switching control part 30 operates the switch part 40 to stop the supply of power from the power supply part 10 to the apparatus 50.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply device and a printing apparatus.

Conventionally, for example, as described in Patent Document 1, when power supply is stopped, a switch connected to a load to which power is supplied is disconnected, so that the stored power is supplied to the load. There is known a power supply device that prevents this.
FIG. 15 is a circuit configuration diagram of a conventional power supply device. At the same time as the power supply unit 10 stops supplying power, the switch unit 40 is disconnected and transitions to an off state, and power supply from the capacitor 15 of the power supply unit 10 to the device 50 is blocked.
FIG. 16 is a diagram showing a change in voltage value over time when the power supply of the conventional power supply device is turned off, and shows a transition of voltage value over time at a measurement point 60c in FIG. As shown in FIG. 16, when the supply of power is stopped at time t1, when the switch unit 40 is not disconnected, the voltage value at the measurement point 60c gradually decreases with time as shown by the broken line by free discharge. . On the other hand, when the switch unit 40 is disconnected, the voltage value at the measurement point 60c rapidly decreases as shown by the solid line.

JP 2004-336894 A

However, in a printing apparatus such as a printer having a power supply device, when the main power supply is turned off and power supply is stopped, the consumption state of consumables such as ink cartridges is stored in the storage device of the printer. There is a problem in that post-processing cannot be executed if processing is necessary and the switch unit 40 is immediately disconnected after power supply is stopped.
The present invention has been made in view of the above-described problems, and an object thereof is to efficiently stop power supply in a printing apparatus.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A power supply device according to this application example is a power supply device that supplies power to a device with power supplied from a power supply unit having a charge / discharge function, and the switch unit that selectively connects the power supply unit and the device; A switching control unit that detects a voltage value of the power and controls switching of the switch unit based on the voltage value, and the switching control unit includes the voltage of the power supplied by the charge / discharge function. When the value transitions from a state exceeding a reference value to a state below the reference value, the power supply from the power supply unit to the device is stopped by operating the switch unit.

  According to such a configuration, when the voltage value of the power supplied by the charge / discharge function transits from a state exceeding the reference value to a state below the reference value, the switching control unit selectively connects the power supply unit and the device. The switch unit to be switched is switched to stop the power supply from the power supply unit to the device. Therefore, when the supply of power to the power supply unit is stopped and the power is supplied by the charge / discharge function, the supply power continues until the voltage value of the supply power falls below the reference value due to the discharge. Processing can be executed. Furthermore, when the voltage value transitions to a state below the reference value, the power supply to the device can be stopped immediately.

[Application Example 2]
In the power supply device according to the application example, the switch unit connects the power supply unit and the plurality of devices, and the switching control unit sets the detected voltage value and the plurality of devices. It is preferable to operate the switch unit based on the reference value to be stopped to stop the supply of power for each device.

  According to such a configuration, it is possible to set the time during which power is supplied by the charge / discharge function according to the reference value set for each of a plurality of devices. Can be set.

[Application Example 3]
In the power supply device according to the application example described above, when a current exceeding a rating flows, the power supply unit includes a fuse that cuts off the connection between the power supply unit and the device, and the switching control unit includes the front and rear stages of the fuse. It is preferable to detect the voltage value.

  According to such a configuration, the fusing of the fuse can be detected quickly and reliably by detecting the voltage value at the front stage and the rear stage of the fuse.

[Application Example 4]
In the power supply device according to the application example, the power supply device supplies power supplied from a power supply unit having a charge / discharge function to a device, and when a current exceeding a rating flows, the power supply unit and the device A fuse that cuts off the connection, a switch that is connected in parallel with the device between the power supply and the fuse, and that selectively discharges the power supplied from the power supply, and the power supply A switching control unit that detects a voltage value supplied from the unit and controls switching of the switch unit based on the voltage value, and the switching control unit is configured to control the power supplied by the charge / discharge function. When the voltage value transitions from a state exceeding the reference value to a state below the reference value, the power supplied from the power supply unit is discharged by operating the switch unit. The features.

  According to such a configuration, when the voltage value of the power supplied from the power supply unit having the charge / discharge function transits from a state exceeding the reference value to a state below the reference value, the switching control unit is supplied from the power supply unit. The switch unit that selectively discharges the generated electric power is switched and discharged to stop the supply of electric power to the device. Therefore, when the power from the power supply unit is stopped, the power supply is continued by the discharge function until the voltage value transitions to a state below the reference value, so that the post-processing can be executed with the supplied power. Furthermore, when the voltage value transitions to a state below the reference value, the power supply to the device can be stopped immediately.

[Application Example 5]
In the power supply device according to the application example described above, it is preferable that the switch unit includes a plurality of resistance values, and the switching control unit sets the reference value based on the resistance values.

  According to such a configuration, by disposing a plurality of switch units having different resistance values, it is possible to pass through the switch unit having a resistance value corresponding to the voltage at the time of discharging, so that overcurrent can be suppressed.

[Application Example 6]
And even if it is a case where supply of electric power is stopped by having a power supply device as described above, electric power is supplied by the charge / discharge function until the voltage value transitions to a state below the reference value. When the post-processing is executed and the voltage value transitions to a state below the reference value, the power supply to the device can be stopped immediately, so that an efficient and safe printing apparatus can be realized.

1 is a diagram illustrating a schematic configuration of an ink jet printer according to a first embodiment. The circuit block diagram of a high voltage circuit. The block diagram which shows the function structure of a switching control part. The figure which shows the change of the voltage value accompanying the time passage at the time of power-off in a measurement point. FIG. 4 is a circuit configuration diagram of a high voltage circuit according to a second embodiment. The block diagram which shows the function structure of a switching control part. The figure which shows the change of the voltage value accompanying the time passage at the time of power-off in a measurement point. FIG. 5 is a circuit configuration diagram of a high voltage circuit according to a third embodiment. FIG. 6 is a circuit configuration diagram of a high voltage circuit according to a fourth embodiment. FIG. 6 is a circuit configuration diagram of a high voltage circuit according to a fifth embodiment. The block diagram which shows the function structure of a switching control part. FIG. 10 is a circuit configuration diagram of a high voltage circuit according to a sixth embodiment. FIG. 10 is a circuit configuration diagram of a high voltage circuit according to a seventh embodiment. The block diagram which shows the function structure of a switching control part. The circuit block diagram of the conventional power supply device. The figure which shows the change of the voltage value accompanying the time passage at the time of power-off of the conventional power supply device.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
Hereinafter, the power supply device according to the first embodiment will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a schematic configuration of an inkjet printer 5 according to the first embodiment. The ink jet printer 5 is a printing apparatus that ejects ink droplets onto a printing medium such as paper based on image data and prints an image such as a character or an image on the printing medium.
In the inkjet printer 5, the main control unit 130 and the power supply unit 10 are mounted on the main board 110, and the device 50 and the sub control unit 135 are mounted on the sub board 120 arranged away from the main board 110. The high voltage circuit 100 is mounted across the main board 110 and the sub board 120.

The high voltage circuit 100 is one aspect of the power supply device, and supplies a predetermined voltage power supplied from the power supply unit 10 to the main control unit 130, the sub control unit 135, the device 50, the printing unit 160, and the like.
The power supply unit 10 is assumed to be a high-voltage output power supply device inside the inkjet printer 5, for example. In the first embodiment, the voltage value supplied by the power supply unit 10 is about 42V.
The power supply unit 10 has a charge / discharge function. In the first embodiment, a capacitor 15 is assumed for the charge / discharge function. For example, an electrolytic capacitor can be used as the capacitor 15.
The main control unit 130 includes a display unit 140 that displays a print menu and image data, an operation unit 150 that is instructed by a user, and a printing unit 160 that performs processing related to printing, and includes a head and a motor (not shown). Control the function.

The sub control unit 135 controls the driving of the device 50 mounted on the sub board 120.
The apparatus 50 includes a detection circuit for detecting whether or not the ink cartridges 170 for storing the respective color inks are respectively mounted on the inkjet printer 5, a drive circuit for driving the head of the printing unit 160, and a motor for the printing unit 160. Assume a driver drive circuit that drives the motor.
The main control unit 130 and the sub control unit 135 are not shown in the figure, and include hardware resources such as a CPU (Central Processing Unit) and RAM (Random Access Memory), ROM (Read Only Memory), flash memory, and the like. Each function is realized by organic cooperation with various stored software.

FIG. 2 is a circuit configuration diagram of the high voltage circuit 100a constituting the inkjet printer 5.
The high voltage circuit 100a includes a fuse 20, a switching control unit 30a, and a switch unit 40.
The high voltage circuit 100 a supplies power from the power supply unit 10 to the device 50 through the fuse 20 and the switch unit 40.

For example, the fuse 20 is blown when an abnormality occurs such as a short circuit between the fuse 20 and the device 50 and the ground (GND), and the electrical connection is cut off. The fuse 20 has a rating of about 0.5A.
The switching control unit 30a has a voltage value detection function and detects the voltage value at the measurement point 60a (measurement point between the power supply unit 10 and the fuse 20). The switching control unit 30a assumes a control circuit that outputs a signal that causes the switch unit 40 to transition to a connected state (on state) or a disconnected state (off state).
In the first embodiment, the switching control unit 30a outputs a signal that the detected voltage value is less than a reference value, for example, less than 35V, and the switch unit 40 is turned off. In addition, the switching control unit 30a outputs a signal that the detected voltage value is 35V or more and the switch unit 40 is turned on.

For example, 3.3V is used as the driving power source of the switching control unit 30a. The drive power is supplied from a power supply unit different from the power supply unit 10.
The switch unit 40 is disposed between the fuse 20 and the device 50, and selectively switches the electrical connection between the power supply unit 10 and the device 50 by transitioning to an on state or an off state. . Further, the switch unit 40 transitions to an on state or an off state based on a signal output from the switching control unit 30a. In the first embodiment, the switch unit 40 is assumed to be a bipolar transistor.
The power supply unit 10 of the ink jet printer 5 includes a large capacity condenser 15. The capacitance of the capacitor 15 is assumed to be 2000 uF to 3000 uF, for example.

FIG. 3 is a block diagram illustrating a functional configuration of the switching control unit 30a. The switching control unit 30a includes an input unit 32, a voltage detection unit 33, a switch operation determination unit 34, a reference value setting unit 35, and a switch signal output unit 36.
The input unit 32 is connected to a power supply line output from the power supply unit 10 by branching at a measurement point 60a. The voltage detection unit 33 detects the voltage value input to the input unit 32. The reference value setting unit 35 sets a reference value for a voltage value that serves as a reference for switching the switch unit 40. The reference value of the voltage value may be a fixed value (35V) set in advance as in the first embodiment, or may be changeable within a predetermined range.

The switch operation determination unit 34 compares the voltage value detected by the voltage detection unit 33 with the reference value of the voltage value set by the reference value setting unit 35 and determines switching of the switch unit 40. When the switch operation determination unit 34 determines to switch to the on state or the off state, the switch signal output unit 36 generates a signal instructing switching, and outputs the generated signal to the switch unit 40.
FIG. 4 shows a change in voltage value over time when the power is turned off at the measurement point 60c (measurement point between the switch unit 40 and the device 50) when the reference value is set to V1. In this case, when the supply of power is stopped at time t1, free discharge starts and the voltage value decreases. When the time t2 (for example, 0.1 sec to 1.0 sec) elapses from the time t1, the voltage value becomes less than the reference value V1, and the switch unit 40 is switched to the off state.

As a result, the voltage value rapidly decreases, and the voltage value of the high voltage circuit 100a becomes 0V. Therefore, necessary processing can be executed in a state where the voltage value equal to or higher than the reference value V1 is maintained until the time t2 elapses from the time t1.
As is well known, immediately after the power of the main body of the ink jet printer 5 is turned off, electric charge remains in the capacitor 15 and a long time (for example, 300 sec to 600 sec) is required until it is completely discharged. Therefore, when the discharge has not been completed, it can be assumed that an operator may get an electric shock by contacting the current-carrying part, or an element such as an electronic component may be destroyed by inserting or removing a live wire. Therefore, when the power supply to the ink jet printer 5 is stopped, it is desirable that the high voltage circuit 100a rapidly decrease the voltage value.

On the other hand, when the power supply of the inkjet printer 5 is stopped, post-processing such as writing the ink consumption amount of the ink cartridge 170 into the IC in each ink cartridge 170 is necessary.
Accordingly, the post-processing is started when the supply of power to the inkjet printer 5 is stopped, and the voltage value at the time when the post-processing is completed is set to be the reference value V1 of the reference value setting unit 35. In addition, the voltage value of the high voltage circuit 100a can be quickly set to 0V after the end of the post-processing.

As described above, according to the high voltage circuit 100a of the ink jet printer 5 according to the present embodiment, the following effects can be obtained.
(1) When the device 50 of the inkjet printer 5 is stopped, the switch unit 40 is kept on until the post-processing is completed, and the voltage value equal to or higher than the reference value V1 is supplied to the device 50. Since the switch unit 40 can be immediately switched to the OFF state, the ink jet printer 5 that secures functionality and safety can be realized.
(2) By switching the switch unit 40 to the off state, no overcurrent flows even when the switch unit 40 and the device 50 are short-circuited to GND, and the fuse 20 is resistant to melting. Have. In particular, when an assembly process worker or a service person of the ink jet printer 5 performs the disassembly work of the power supply device, an effect of preventing the fuse 20 from being blown can be obtained even if the power supply device is accidentally short-circuited.

(Embodiment 2)
Next, Embodiment 2 of the present invention will be described. In the following description, the same parts as those already described are denoted by the same reference numerals and description thereof is omitted.
FIG. 5 is a circuit configuration diagram of the high-voltage circuit 100b that constitutes the inkjet printer 5 according to the second embodiment.
The high voltage circuit 100b includes a fuse 20, a switching control unit 30b, and switch units 40a and 40b.

The switching control unit 30b has a voltage value detection function and detects the voltage value at the measurement point 60a (measurement point between the power supply unit 10 and the fuse 20). The switching control unit 30b is assumed to be a control circuit that outputs signals that cause the switch units 40a and 40b to transition to an on state or an off state, respectively.
In the second embodiment, the switching control unit 30b outputs a signal that the detected voltage value is less than a first reference value, for example, less than 35V, and the switch unit 40a transitions to an off state. In addition, the switching control unit 30b outputs a signal that the detected voltage value is less than a second reference value, for example, less than 25V, and the switch unit 40b transitions to an off state.

Further, the switching control unit 30b outputs a signal that the detected voltage value is equal to or higher than the first reference value and the switch unit 40a is turned on. In addition, the switching control unit 30b outputs a signal that causes the detected voltage value to be greater than or equal to the second reference value and the switch unit 40b to be turned on.
The switch portions 40a and 40b are arranged in parallel between the fuse 20 and the devices 50a and 50b. That is, the switch unit 40a is disposed between the fuse 20 and the device 50a, and the switch unit 40b is disposed between the fuse 20 and the device 50b.

The switch unit 40a intermittently establishes an electrical connection between the power supply unit 10 and the device 50a by transitioning to an on state or an off state. Similarly, the switch part 40b interrupts the electrical connection of the power supply part 10 and the apparatus 50b by changing to an ON state or an OFF state.
Further, the switch units 40a and 40b transition to the on state or the off state based on the respective signals output from the switching control unit 30b. In the second embodiment, the switch units 40a and 40b are assumed to be bipolar transistors.
FIG. 6 is a block diagram illustrating a functional configuration of the switching control unit 30b. The switching control unit 30b includes an input unit 32, a voltage detection unit 33, switch operation determination units 34a and 34b, reference value setting units 35a and 35b, and switch signal output units 36a and 36b.

The reference value setting units 35a and 35b respectively set reference values (first reference value and second reference value) of voltage values serving as a reference for switching the switch units 40a and 40b.
The switch operation determination units 34a and 34b respectively compare the voltage value detected by the voltage detection unit 33 with the reference value of the voltage value set by the reference value setting units 35a and 35b, and switch the switch units 40a and 40b, respectively. judge. When the switch operation determination units 34a and 34b determine switching to the on state or the off state, the switch signal output units 36a and 36b generate a signal instructing switching, and the generated signals are applied to the corresponding switch units 40a and 40b. Output to.

FIG. 7 shows that when the first reference value is set to V1 and the second reference value is set to V2 having a voltage value lower than V1, the measurement point 60c (measurement point between the switch unit 40a and the device 50a) and The change of the voltage value with time passage at the time of power-off at the measurement point 60d (measurement point between the switch unit 40b and the device 50b) is shown.
In this case, when the supply of power is stopped at time t1, free discharge starts and the voltage value decreases. When the time t2 elapses starting from the time t1, the voltage value becomes less than the first reference value V1, and the switch unit 40a is switched to the off state. As a result, the voltage value rapidly decreases, and the voltage value at the measurement point 60c becomes 0V.

Furthermore, when the time t3 has elapsed from the time t1, the voltage value becomes less than the second reference value V2, and the switch unit 40b is switched to the off state. As a result, the voltage value rapidly decreases, and the voltage value at the measurement point 60d becomes 0V.
Therefore, the first process can be executed in a state where the voltage value equal to or higher than the reference value V1 is maintained until the time t2 elapses from the time t1. In addition, the second process can be executed in a state where the voltage value equal to or higher than the reference value V2 is maintained until the time t3 elapses from the time t1.
As described above, the high-voltage circuit 100b according to the second embodiment has the following effects in addition to the effects described in the first embodiment.
(3) When the supply of power to the inkjet printer 5 is stopped, two post-processes, a first process with a shorter processing time and a second process with a longer processing time than the first process, are executed. it can.
(4) After the end of each post-processing, the voltage value applied to the devices 50a and 50b can be quickly set to 0V.

(Embodiment 3)
FIG. 8 is a circuit configuration diagram of the high-voltage circuit 100c according to the third embodiment.
The high voltage circuit 100c employs an FET (Field Effect Transistor) 45 as a switching function, and performs switching by the FET 45 based on a control signal from the switching control unit 30a.
As described above, according to the high voltage circuit 100c according to the third embodiment, in addition to the effects described in the first embodiment, the following effects can be obtained.
(5) In addition to being cheaper and smaller than a bipolar transistor, the FET 45 can be switched on and off at high speed and with certainty, so that safety can be improved.

(Embodiment 4)
FIG. 9 is a circuit configuration diagram of a high voltage circuit 100d according to the fourth embodiment.
The high voltage circuit 100d includes a resistor 80 in parallel with the switch unit 40a. In the high voltage circuit 100d, when the switch unit 40a is turned off by the control signal from the switching control unit 30a, the power supplied from the power supply unit 10 is supplied to the device 50 through the resistor 80. In this state, when the resistor 80 and the device 50 are short-circuited to GND, it is possible to prevent an overcurrent from flowing.
The resistance value of the resistor 80 is assumed to be, for example, 1 kΩ to 10 kΩ. When the voltage value from the power supply unit 10 is 42 V and the resistor 80 and the device 50 are short-circuited to GND, the flowing current value is 4.2 mA to 42 mA or less.

In addition, since the current passes through the resistor 80, the charge discharge time can be lengthened, so that the processing time after the power source is switched to the off state can be secured.
As described above, the high voltage circuit 100d according to the fourth embodiment has the following effects in addition to the effects described in the first embodiment.
(6) By adding the resistor 80 in parallel with the switch unit 40a, when the resistor 80 and the device 50 are short-circuited to GND, an overcurrent can be prevented, so safety is improved and processing time is secured. Can be planned.

(Embodiment 5)
FIG. 10 is a circuit configuration diagram of a high-voltage circuit 100e that constitutes the inkjet printer 5 according to the fifth embodiment.
The high voltage circuit 100e includes a fuse 20, a switching control unit 30c, and a switch unit 40.
The switching control unit 30c has a voltage value detection function, and includes a measurement point 60a (a measurement point between the power supply unit 10 and the fuse 20) and a measurement point 60b (a fuse 20 and a switch unit). The voltage value at a measurement point between 40 and 40 is detected to determine whether the fuse 20 is blown.

In the fifth embodiment, in the normal state, the voltage value at the measurement point 60a is the same as the voltage value at the measurement point 60b. However, when the fuse 20 is blown, the measurement point with respect to the voltage value at the measurement point 60a is measured. The voltage value of 60b falls extremely. The switching control unit 30c determines whether the fuse 20 is blown by detecting a potential difference between the two voltage values.
In addition, when the fuse 20 is not blown, the switching control unit 30c outputs a signal that the detected voltage value is less than a reference value, for example, 35V, and the switch unit 40 transitions to the OFF state. Outputs a signal that transitions to the ON state.
FIG. 11 is a block diagram illustrating a functional configuration of the switching control unit 30c. The switching control unit 30c includes input units 32a and 32b, voltage detection units 33a and 33b, a voltage difference determination unit 37, and a determination signal output unit 38.

The input units 32a and 32b are connected by branching the power supply lines output from the power supply unit 10 at the measurement points 60a and 60b, respectively. The voltage detection units 33a and 33b detect voltage values input to the input units 32a and 32b, respectively. The voltage difference determination unit 37 determines the difference between the voltage values detected by the voltage detection units 33a and 33b. The determination signal output unit 38 determines that the fuse 20 is blown when the difference determined by the voltage difference determination unit 37 exceeds a predetermined reference value, and outputs a blow signal indicating that the fuse 20 is blown.
The ink jet printer 5 displays a message on the display unit 140 of the ink jet printer 5 based on the fusing signal and notifies the user. In this case, the inkjet printer 5 may notify the user with a warning sound or a voice.
As described above, according to the high voltage circuit 100e according to the fifth embodiment, in addition to the effects described in the first embodiment, the following effects can be obtained.
(7) By detecting whether or not the fuse 20 is blown during normal operation, the user can be notified of an abnormality that has occurred on the circuit.

(Embodiment 6)
FIG. 12 is a circuit configuration diagram of a high-voltage circuit 100f that configures the inkjet printer 5 according to the sixth embodiment.
In the high voltage circuit 100 f, the switch unit 40 is disposed in parallel with the device 50 between the power supply unit 10 and the fuse 20.
In the normal state, the switch unit 40 is in an off state. When the charge remains in the capacitor 15 and the voltage value at the measurement point 60a is equal to or lower than the reference value, the switch unit 40 is turned on based on a signal output from the switching control unit 30a. . At this time, the electric charge remaining in the capacitor 15 passes through the switch unit 40 and is quickly discharged to GND.

As described above, the high-voltage circuit 100f according to the sixth embodiment has the following effects in addition to the effects described in the first embodiment.
(8) When the power supply of the ink jet printer 5 is turned off and the voltage value becomes equal to or lower than the reference value, the electric charge in the capacitor 15 is quickly discharged, thereby causing electric shock due to contact with the energized part or hot plugging / unplugging. There is an effect of improving safety such as preventing the destruction of 50.
(9) By disposing the switch unit 40 between the fuse 20 and the power supply unit 10, it is possible to avoid an overcurrent from flowing to the fuse 20 when discharging to the GND, and to withstand the fusing of the fuse 20. Can have.

(Embodiment 7)
FIG. 13 is a circuit configuration diagram of a high-voltage circuit 100g that configures the inkjet printer 5 according to the seventh embodiment.
In the high voltage circuit 100g, a plurality of switch units 40a, 40b, and 40c are arranged in parallel with the device 50 between the power supply unit 10 and the fuse 20.
The plurality of switch units 40a, 40b, and 40c have different resistance values. For example, 22Ω is assumed for the switch unit 40a, 47Ω for the switch unit 40b, and 100Ω for the switch unit 40c.
The switching control unit 30d has a voltage value detection function and detects the voltage value at the measurement point 60a. The switching control unit 30d controls switching of the on / off states of the switch units 40a, 40b, and 40c, respectively, according to the detected voltage value.

In the normal state, the switch units 40a, 40b, and 40c are off. When the power of the main body of the inkjet printer 5 is turned off, when the electric charge remains in the capacitor 15 and the voltage value at the measurement point 60a is equal to or lower than the first reference value, first, the switching control unit 30d Based on the output signal, the switch unit 40a transitions to the on state.
The charge remaining in the capacitor 15 passes through the switch unit 40a and is quickly discharged to GND.
Further, when the second reference value is set to a half of the first reference value and the voltage value at the measurement point 60a becomes equal to or lower than the second reference value, the switch unit is based on the signal output from the switching control unit 30d. 40b transitions to the ON state. In this case, the switch unit 40a transitions to the off state.

Further, when the third reference value is set to 1/4 of the first reference value, and the voltage value at the measurement point 60a is equal to or lower than the third reference value, the switch is set based on the signal output from the switching control unit 30d. The unit 40c transitions to the on state. In this case, the switch unit 40b transitions to the off state.
For example, if the first reference value is 40V, the second reference value is 20V, and the third reference value is 10V, the switch unit 40a has a maximum of 0.40A, the switch unit 40b has a maximum of 0.43A, and the switch unit 40c has a maximum of 0. 45A.
Accordingly, it is possible to smooth the amount of current discharged to the GND through the switch units 40a, 40b, and 40c.

FIG. 14 is a block diagram illustrating a functional configuration of the switching control unit 30d. The switching control unit 30d includes an input unit 32, a voltage detection unit 33, switch operation determination units 34a, 34b, 34c, reference value setting units 35a, 35b, 35c, and switch signal output units 36a, 36b, 36c.
The reference value setting units 35a, 35b, and 35c set reference values (first reference value, second reference value, and third reference value) of voltage values that serve as references for switching the switch units 40a, 40b, and 40c, respectively.
The switch operation determination units 34a, 34b, and 34c respectively compare the voltage value detected by the voltage detection unit 33 with the reference value of the voltage value set by the reference value setting units 35a, 35b, and 35c, and switch units 40a and 40b. , 40c is determined.

When the switch operation determination units 34a, 34b, and 34c determine switching to the on state or the off state, the switch signal output units 36a, 36b, and 36c generate a signal instructing switching, and the generated signals are applied to the corresponding switches. It outputs to the part 40a, 40b, 40c.
For example, when the voltage value at the measurement point 60a is smaller than the first reference value and larger than the second reference value, the switch signal output unit 36a outputs a signal for switching the switch unit 40a to the on state.
When the voltage value at the measurement point 60a is smaller than the second reference value and larger than the third reference value, the switch signal output unit 36a outputs a signal for switching the switch unit 40a to the OFF state, and further the switch signal output unit 36b. Outputs a signal for switching the switch unit 40b to the ON state.

When the voltage value at the measurement point 60a is smaller than the third reference value, the switch signal output unit 36b outputs a signal for switching the switch unit 40b to the off state, and the switch signal output unit 36c turns on the switch unit 40c. Outputs a signal that transitions to a state.
In the seventh embodiment, the order decreases in the order of the first reference value, the second reference value, and the third reference value. Further, the number of the switch units 40 is not limited.
As described above, the high voltage circuit 100g according to the seventh embodiment has the following effects in addition to the effects described in the first embodiment.
The high voltage circuit 100g includes switch units 40a, 40b, and 40c, and can further improve safety by adjusting the amount of discharge current to GND according to the voltage value.

As mentioned above, although this invention was demonstrated based on embodiment shown in figure, this invention is not limited to this embodiment, The modification as described below can also be assumed.
(1) The printing apparatus to which the power supply device is applied is not limited to the inkjet printer 5. It can also be applied to laser, dot head and thermal transfer printers. Further, the present invention may be applied to an information processing apparatus having the high voltage circuit 100.

  DESCRIPTION OF SYMBOLS 5 ... Inkjet printer, 10 ... Power supply part, 15 ... Condenser, 20 ... Fuse, 30a, 30b, 30c, 30d ... Switching control part, 32, 32a ... Input part, 33, 33a ... Voltage detection part, 34, 34a ... Switch operation determination unit, 35, 35a ... reference value setting unit, 36, 36a, 36b, 36c ... switch signal output unit, 37 ... voltage difference determination unit, 38 ... determination signal output unit, 40, 40a, 40b, 40c ... switch 45, field effect transistor, 50, 50a, 50b ... device, 60a, 60b, 60c, 60d ... measurement point, 80 ... resistor, 100, 100a, 100b, 100c, 100d, 100e, 100f, 100g ... high voltage Circuit 110 110 Main board 120 Sub board 130 Main controller 135 Sub controller 140 Table Department, 150 ... operation unit, 160 ... printing section, 170 ... ink cartridge.

Claims (6)

A power supply device that supplies power supplied from a power supply unit having a charge / discharge function to a device,
A switch unit for selectively connecting the power supply unit and the device;
A switching control unit that detects a voltage value of the power and controls switching of the switch unit based on the voltage value;
The switching control unit operates the switch unit to operate the switch unit from the power supply unit when the voltage value of the power supplied by the charge / discharge function transits from a state exceeding a reference value to a state below the reference value. A power supply device that stops supply of the power to the device. The power supply device according to claim 1,
The switch unit connects the power supply unit and the plurality of devices, respectively.
The switching control unit operates the switch unit based on the detected voltage value and the reference value set for each of the plurality of devices, and stops the supply of power for each device. A featured power supply. The power supply device according to claim 1,
When a current exceeding the rating flows, it has a fuse that cuts off the connection between the power supply unit and the device,
The power supply apparatus according to claim 1, wherein the switching control unit detects the voltage value before and after the fuse. A power supply device that supplies power supplied from a power supply unit having a charge / discharge function to a device,
When a current exceeding the rating flows, a fuse that cuts off the connection between the power supply unit and the device,
A switch unit that is connected in parallel with the device between the power supply unit and the fuse, and selectively discharges the power supplied from the power supply unit;
A switching control unit that detects a voltage value supplied from the power supply unit and controls switching of the switch unit based on the voltage value;
The switching control unit operates the switch unit to operate the switch unit from the power supply unit when the voltage value of the power supplied by the charge / discharge function transits from a state exceeding a reference value to a state below the reference value. A power supply apparatus that discharges the supplied power. The power supply device according to claim 4,
The switch part is composed of a plurality of different resistance values,
The switching control unit sets the reference values based on the resistance values, respectively.   A printing apparatus comprising the power supply device according to claim 1.

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