JP2023019822A - Electronic device and liquid ejection device - Google Patents

Abstract

To inform a user of whether a voltage has decreased lower than a dangerous voltage or not.SOLUTION: The present invention has: an interlock unit that outputs a switching signal in conjunction with an opening operation of a door of a power source unit; a cutoff switching unit that, based on an output of the switching signal by the opening operation, switches a power breaker, which disconnects the power source unit from an external supply power source for supplying power to the power source unit, to power cutoff; a discharge unit that, based on the output of the switching signal by the opening operation, releases electrical charges remaining in a circuit included in the power source unit separated from the external supply power source by the power breaker; a comparison unit that compares a residual voltage level of the circuit with a set voltage level equal to or below a dangerous voltage; and a warning output unit that outputs an alarm signal until the residual voltage level drops down to at least the set voltage level in the comparison unit.SELECTED DRAWING: Figure 1

Description

The present invention relates to electronic equipment and liquid ejecting apparatuses.

2. Description of the Related Art Conventionally, in electronic equipment, a power supply is housed inside a door, and the door is provided with an interlock mechanism to prevent an operator from receiving electric shock or burns during maintenance of the power supply. When the operator opens the door, the interlock mechanism is activated and the power supply to the electronic equipment from the external power supply system is physically cut off.

Patent Literature 1 discloses a configuration in which a mechanical interlock is replaced with an electromagnetic breaker for the purpose of increasing the flexibility of the switchboard. Further, Patent Document 2 discloses a configuration in which an interlock device is provided for the purpose of deactivating the circuit.

However, even if the power supply from the outside is physically cut off by a mechanical or electromagnetic interlock mechanism as in the conventional system, there is a residual electric charge in the power supply immediately after the door is opened. It is supposed that the voltage will drop below the dangerous voltage within a predetermined time such as 5 seconds after the door is opened, but if the voltage does not drop as expected, the safety of workers cannot be ensured. There is a problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an interlock electronic device and a liquid ejecting apparatus capable of informing a user whether or not the voltage has dropped below the dangerous voltage. do.

In order to solve the above-described problems and achieve the object, the present invention is based on an interlock unit that outputs a switching signal in conjunction with opening operation of a door of a power supply unit, and output of the switching signal by the opening operation. a cutoff switching unit for switching a power circuit breaker that disconnects the power supply unit from an external power supply that supplies power to the power supply unit to cut off power; a discharge unit that discharges electric charges remaining in a circuit included in the power supply unit that is separated from the external power supply; and a comparison unit that compares the residual voltage level of the circuit with a set voltage level equal to or lower than the dangerous voltage. and a warning output section for outputting a warning signal until the residual voltage level in the comparison section is reduced to at least the set voltage level.

ADVANTAGE OF THE INVENTION According to this invention, it is effective in being able to tell a user whether the voltage dropped to lower than a dangerous voltage.

FIG. 1 is a schematic diagram showing the configuration of an inkjet printer, which is a liquid ejecting apparatus according to an embodiment. FIG. 2 is a diagram showing an example of the configuration of electrical equipment that the inkjet printer has. FIG. 3 is a diagram showing an example of the appearance of the door and the configuration of the system power supply input section of the accommodation section inside the door. FIG. 4 is a diagram illustrating an example of a circuit configuration of a system power supply input unit; FIG. 5 is a diagram showing an example of a configuration of a drive unit that switches off a main breaker in conjunction with an interlock. FIG. 6 is a diagram showing an example of the configuration of the interlock section and the interlock section. FIG. 7 is a diagram showing an example in which a terminating circuit is provided in the system power supply input section. FIG. 8 is an explanatory diagram of the configuration of the termination circuit. FIG. 9 is a diagram illustrating an example of threshold value setting for a comparator. FIG. 10 is a diagram showing an example of an arrangement of LED lights. FIG. 11 is a diagram showing an example of a lighting circuit for a red LED light and a white LED light. FIG. 12 is an explanatory diagram of the operation of the logic circuit. FIG. 13 is a diagram showing an example of the arrangement of LED lights according to Modification 1. As shown in FIG. FIG. 14 is a diagram illustrating a circuit configuration in which a red LED light and a white LED light are provided in each housing portion of each door. FIG. 15 is a diagram for explaining a circuit configuration when a red LED light and a white LED light are provided in each housing portion of each door. FIG. 16 is a diagram illustrating an example of a basic configuration of a termination circuit according to modification 2; FIG. 17 is an explanatory diagram of a logic circuit. FIG. 18 is a diagram illustrating an example of threshold value setting for a comparator. 19 is a diagram illustrating an example of a configuration of a relay driving circuit according to Modification 3. FIG. FIG. 20 is a diagram showing an example of inputs and outputs in a logic circuit.

Exemplary embodiments of an electronic device and a liquid ejection device will be described in detail below with reference to the accompanying drawings. A liquid ejecting apparatus, which is an example of an electronic device, will be described in detail below.

(Embodiment)
The electronic device according to the embodiment can be applied to an electronic device that operates by power supply from the outside. For example, an electronic device operates on power supplied by a power supply unit of the electronic device from a three-phase system power supply (commercial power supply, also called an external AC power supply), which is an example of an external power supply supplied from a switchboard in a building. Such electronic devices have different configurations depending on the application or purpose. In the following, the configuration of a liquid ejecting apparatus, which is one type of electronic device, will be taken as an example, and the configuration of mainly the power supply section of the electronic device will be described in detail.

A liquid ejection device is a liquid ejection device that ejects liquid from a liquid ejection portion onto a recording medium, and operates with an external power supply. There are various types of liquid ejection apparatuses, such as inkjet printers and 3D modeling apparatuses. In the following description, the liquid is assumed to be ink, but the liquid is not limited to this. Also, although the recording medium is assumed to be paper, the recording medium is not limited to this. For example, the storage medium may be cloth or other material such as plastic.

FIG. 1 is a schematic diagram showing the configuration of an inkjet printer, which is a liquid ejecting apparatus according to an embodiment. The inkjet printer 1 shown in FIG. 1 has a controller board 10, an operation panel 11, a scanning mechanism 20, an ink supply unit 30, a conveying mechanism 40, and a power supply section 50. These sections are connected to the inkjet printer 1. is protected by an enclosure. An inlet 52 for supplying external power (corresponding to "external supply power") to the power supply unit 50 of the inkjet printer 1 and a main switch M1, which is the main power switch of the inkjet printer 1, are provided on the side of the housing. It is An outlet on the building side and the inlet 52 are connected by a power cord to supply external power to the power supply unit 50 .

The controller board 10 centrally controls the entire inkjet printer 1 . The operation panel 11 communicates with the controller board 10 and transmits various operation signals to the controller board 10 . When the activation button 12 is pressed, the power of the controller board 10 is turned on, and the controller board 10 communicates with each electrical equipment to activate the inkjet printer 1 .

The scanning mechanism 20 and the ink supply unit 30 mainly correspond to a liquid ejection section. The scanning mechanism 20 moves an inkjet head (hereinafter referred to as an IJ head) along the X-axis and Y-axis guide rails in the main scanning direction (X-axis direction) or sub-scanning direction (Y-axis direction) of the recording paper. and a scanning mechanism that is motorized along. The IJ head is mounted on a carriage and used, and the carriage is motor-driven along the X-axis and Y-axis guide rails so that the IJ head scans the entire recording paper. When the recording paper is scanned while the recording paper is fixed as in the flatbed method, two-dimensional scanning is performed by moving the carriage in the X-axis direction and the Y-axis direction.

The ink supply unit 30 has an ink tank for supplying ink to the IJ head, a negative pressure control section, and the like.

The transport mechanism 40 is a transport mechanism that transports the recording paper. Note that the transport mechanism 40 may be configured to transport the recording paper in the Y-axis direction. In this case, the scanning mechanism 20 performs one-dimensional scanning by moving the carriage in the X-axis direction.

The power supply unit 50 is accommodated inside a door 500 provided on the housing of the inkjet printer 1 . When the door 500 is opened, the power source section 50 is exposed. When a worker or the like performs work such as maintenance of the power supply unit 50 , the work is performed with the door 500 opened.

The power supply unit 50 has a system power supply input unit 51 (see FIG. 3) for taking in a system power supply, which is an external power supply. The door 500 is an interlock type door. Although the details will be described later, an interlock section is employed that cuts off the power supply from the system power supply to the system power supply input section 51 in conjunction with the opening operation of opening the door 500 .

FIG. 2 is a diagram showing an example of the configuration of electrical equipment that the inkjet printer 1 has. The controller board 10 includes an SoC (System on a Chip) 101, a ROM (Read Only Memory) 102, an SDRAM (Synchronous Dynamic Random Access Memory) 103, an image data processing unit 104, an IJ control unit 105, and a drive control unit. It has a unit 106 , an IO (Input Output) control unit 107 , a negative pressure control unit 108 and a PHY 109 .

The SoC 101 is a chip containing a CPU (Central Processing Unit) and peripherals. ROM 102 and SDRAM 103 are memories that store programs or data. The ROM 102 is, for example, a flash ROM. Note that the CPU and memory may be integrated and provided as a SiP (System in a Package).

An image data processing unit 104 converts an image file into image data for the IJ head 203 and corrects the image data.

The IJ control unit 105 controls the operation of the IJ head 203 and overall ejection control via the head I/F board 201 . The head I/F board 201 causes each IJ head 203 to eject ink by driving each amplifier (AMP) 202 . In the example shown in FIG. 2, the IJ heads 203 are composed of eight sets of eight colors.

Head I/F board 201 controls stepping motor 212 , heater 213 , and air pump 214 via actuator I/F board 211 . A stepping motor 212 drives a carriage on which eight sets of IJ heads 203 are mounted. A heater 213 preheats the ink sub-tank. An air pump 214 discharges the air in the ink.

When the inkjet printer 1 has a flatbed type configuration, the drive control unit 106 controls the servo motor 222 and the servo motor driver 221 and the Y-axis motor driver 223 corresponding to the X-axis and the Y-axis, respectively. Drive motor 224 . The X-axis motor driver 221 controls the servomotor 222 based on position output information output by the encoder of the servomotor 222 . Also, the Y-axis motor driver 223 controls the servomotor 224 based on the position output information output by the encoder of the servomotor 224 .

The IO control unit 107 is connected to an ink pump 231 , a mechanism motor 232 , a door switch 233 , a limit/zero sensor 234 and a negative pressure sensor 235 that the inkjet printer 1 generally has.

The ink pump 231 is a pump that supplies ink from the main tank. The mechanism motor 232 is used for maintenance and the like. Door switch 233 detects opening and closing of door 500 .

The limit/zero sensor 234 is a sensor that detects limit/zero of the X-axis and Y-axis drive systems. The negative pressure sensor 235 is a sensor for forming negative pressure.

Negative pressure control unit 108 drives air pump 214 for body circulation during standby.

A PHY 109 is a PHY device such as a network and connects with the host PC 2 .

When the activation button 12 is pressed, the controller board 10 is powered on and communicates with each electrical equipment of the inkjet printer 1 to activate the inkjet printer 1 . Also, the controller board 10 controls the entire inkjet printer 1 by executing a corresponding program on the SoC 101 to perform processes such as ejection control. In FIG. 2, the electrical equipment other than IO is driven by electric power generated from an external power source. Each electrical equipment is driven by power generated by an AC (Alternating Current)/IF (InterFase) circuit. The electrical equipment is not limited to DC drive or AC drive, and may be either. As the size and weight of the ink jet printer increase, an AC drive motor is used as the drive motor. Each equipment drives.

Next, the configuration of the power supply unit 50 that distributes system power to each electrical equipment will be described. First, the configuration of the interlock of the power supply unit 50 will be described, and then the circuit configuration of the electrical system of the power supply unit 50 will be described in detail.

FIG. 3 is a diagram showing an example of the appearance of the door 500 and the configuration of the system power supply input section 51 of the accommodation section in the door 500. As shown in FIG. FIG. 3 shows an example in which the three-phase and three single-phase system power input units 51 are housed in separate doors 500 . Although two doors 500 will be described here as an example, the number of doors 500 is not limited to two. The number of doors may be further increased or reduced to one depending on the scale of the system power input unit. For example, if the system power supply input unit 51 is of a small scale such as a single-phase system, it may be housed in one door 500 . In either case, the following configuration for one door can be applied.

FIG. 3(a) is an external view of two doors 500-1 and 500-2 which are separate doors 500, and FIG. 3(b) is a door 500-1 and a door 500-2. 5 is an external view of switchboards 51-1 and 51-2 of a system power supply input unit 51 for three-phase and three single-phase systems. FIG. Here, the inlet 52 is provided on the housing side surface outside the doors 500-1 and 500-2. An outlet on the building side and the inlet 52 are connected by a power cord, and system power is supplied to the system power input unit 51 .

System power supplied from the inlet 52 is supplied to the switchboards 51-1 and 51-2 by manually turning on the main switch M1 of the inkjet printer 1. FIG.

As shown in FIG. 3A, the doors 500-1 and 500-2 are provided with levers 501 and 502, respectively. Doors 500-1 and 500-2 are opened by operating levers 501 and 502, respectively. An operation for opening the doors 500-1 and 500-2 is called an opening operation. The interlock 511 and the interlock 512 shown in FIG. 3(b) are interlocked with the opening operation of the door 500-1 and the door 500-2, respectively, to cut off the supply of external power to the system power input unit 51. A device that outputs a signal.

FIG. 4 is a diagram showing an example of the circuit configuration of the system power supply input unit 51. As shown in FIG. When the main switch M1 is manually turned on, system power is supplied from the inlet 52 to the system power input unit 51 via the main breaker B1. As shown in FIG. 4, the inlet 52 connects the live line (L line) of each of the three phases, namely the first phase L1, the second phase L2, and the third phase L3, the neutral N line, and the ground (PE ) and The system power supply input unit 51 receives a three-phase AC power supply from an inlet 52, and outputs three single-phase, two-wire power supplies that are a combination of one of the three phases and a neutral N. and supplies it to each corresponding AC/IF circuit. Here, each AC I/F circuit corresponds to an "AC circuit".

The AC I/F circuit 801 is heavier as the ink jet printer 1 is larger, and a large output motor, a large intake/exhaust blower, and the like are AC three-phase driven, so the three-phase system power supply is supplied as it is. That is, the AC I/F circuit 801 is directly connected to the L1A line corresponding to the first phase L1 line, the L2A line corresponding to the second phase L2 line, and the L3A line corresponding to the third phase L3 line. . The AC I/F circuit 801 is a main circuit including an inverter and a filter, and drives a large output motor, a large intake/exhaust blower, etc. connected by a cable with 3-phase AC.

The AC I/F circuit 802 is connected to the L1B line branched from the first phase L1 line and the N_B line branched from the neutral N line. That is, the AC I/F circuit 802 is distributed with a single-phase two-wire power source. The AC I/F circuit 802 has a DC power supply generation circuit, and supplies a necessary DC voltage to each DC circuit such as a controller.

The AC I/F circuit 803 is connected to the L2C line branched from the second phase L2 line and the N_C line branched from the neutral N line. That is, the AC I/F circuit 803 is also distributed with the single-phase two-wire power supply. The AC I/F circuit 803 supplies power to an AC single-phase driven servo motor or servo motor driver through a cable or the like.

The AC I/F circuit 804 is connected to the L3D line branched from the third phase L3 line and the N_D line branched from the neutral N line. That is, the AC I/F circuit 804 is also distributed with a single-phase two-wire power supply. When a large number of IJ heads 203, such as eight, are provided as in this example, the circuit of the AMP 202 that generates drive voltage for the IJ heads 203 consumes a large amount of power. The AC I/F circuit 804 is equipped with a DC generation circuit capable of supplying high voltage and large current, and drives the AMP 202 with DC.

Here, the AC I/F circuits 801 to 804 are examples of "circuits" having residual charges. Depending on the configuration of the electronic device, the "circuit" having residual charge may be only the AC I/F circuit 801, but as in the present embodiment, all or any of the AC I/F circuits 802, 803, and 804 may be included. It may contain one of the Note that the "circuit" is not limited to these configurations. Depending on the number and scale of the electrical equipment, the number, division method, configuration, etc. may also differ. For example, it may be only a filter, or in some cases only a fuse. Also, a high-performance DC generation circuit, voltage adjustment circuit, or the like may be added.

The three-phase AC I/F circuit 801 after potential distribution and the single-phase two-wire AC I/F circuits 802, 803, and 804 after potential distribution are provided with corresponding relays RE1, RE2, RE3, and RE4, respectively. is provided. Each relay RE1, RE2, RE3, RE4 operates under the direction of the controller of the controller board 10. FIG. By closing any one of the relays RE1, RE2, RE3 and RE4 according to an instruction from the controller board 10, the electrical equipment corresponding to the closed relay RE1, RE2, RE3 and RE4 is powered on. For example, when relay RE1 is closed, the three-phase motor is powered on. Also, when the relay RE2 is closed, the various DC circuits are powered on. Further, when the relay RE3 is closed, the power of the servomotor is turned on. Also, when the relay RE4 is closed, the power of the AMP is turned on.

In this example, the main breaker B1 is provided as a "power circuit breaker" in the preceding stage of the power distribution, but individual breakers may be provided as "power circuit breakers" in the electric circuits after the power distribution.

When the main switch M1 is turned on and the start button 12 is pressed, the relay RE2 is closed and the controller board 10 is powered on. The controller board 10 responsively closes one or more of the relays RE1, RE3, RE4 to turn on the necessary electrical equipment.

FIG. 5 is a diagram showing an example of the configuration of a drive unit that switches off the main breaker B1 in conjunction with an interlock. Here, the driving section is an example of a "shutoff switching section", and is disconnected from the external power supply by switching off the main breaker B1, that is, by switching to cut off the power. As shown in FIG. 5, the drive unit 811 has a configuration in which the shunt switch SW1 is driven by the relays RE5 and RE6, so that the shunt switch SW1 physically turns the switches of the main breaker B1 to the OFF side (power cutoff side). switch. Once each switch of the main breaker B1 is physically turned on, it remains on after that. Therefore, all switches are turned off by the drive unit 811 when the door is opened. Relays RE5 and RE6 are open when door 500-1 and door 500-2 are open and closed when door 500-1 and door 500-2 are closed.

The shunt switch SW1 is associated with an actuator that advances and retracts the drive bar 8110 in one direction, for example, by an actuator. When one of the doors 500-1 and 500-2 is opened, the detection signal of the shunt switch SW1 becomes Low, and the drive bar 8110 moves in one direction to physically turn off each physical switch of the main breaker B1. to return to the initial position. Note that when turning on the main breaker B1, it is done manually, not automatically, due to safety standards. When turning on the main breaker B1, turn off the main switch M1 once, turn on the main breaker B1, close the doors 500-1 and 500-2, and turn on the main switch M1 again. Power can be turned on.

FIG. 6 is a diagram showing an example of the configuration of the interlock section 511 and the interlock section 512. As shown in FIG. The interlock unit 511 is configured to open the relay RE5, and the interlock unit 512 is configured to open the relay RE6. Both the interlock section 511 and the interlock section 512 have the same configuration. Here, the configuration of the interlock section 511 will be described, and the description of the interlock section 512 will be omitted since it will be repeated.

FIG. 6(a) illustrates the state of relay RE5 when door 500-1 is opened, and FIG. 6(b) illustrates the state of relay RE5 when door 500-1 is closed. It is a figure to do.

As shown in FIG. 6(a), the interlock mechanism K1 has a spring-type interior, and the push rod 5000 advances and retreats according to the opening and closing of the door 500-1. The switch SW2 is switched between open and closed as the push rod 5000 advances and retreats. In this example, switch SW2 is closed when door 500-1 is open, and switch SW2 is open when door 500-1 is closed.

As shown in FIG. 6A, when the switch SW2 is closed, the base of the transistor Tr is grounded and turned off. As a result, a current flows from the device power supply V1 to the coil C1 via the resistor R1, and the b-contact relay RE5 is opened. Further, as shown in FIG. 6B, when the switch SW2 is open, a drive voltage is applied to the base of the transistor Tr from the device power source V1 through the resistor R2 to turn on the transistor Tr. As a result, a current flows between the emitter and collector of the transistor Tr through the resistor R1, and the relay RE5 is closed without being driven by the coil C1.

As shown in FIG. 5, relay RE5 and relay RE6 are connected in series. Therefore, if both the door 500-1 and the door 500-2 are not closed, one of the relays RE5 and RE6 is open, so that the input to the shunt switch SW1 is turned off and the drive bar 8110 operates the main switch. Breaker B1 is turned off.

FIG. 7 is a diagram showing an example in which the system power input unit 51 is provided with a terminating circuit. Here, the terminating circuit corresponds to a “discharging section” that discharges electric charges remaining in the circuit included in the system power supply input section 51 . FIG. 7 shows an example in which a terminating circuit is provided in the electric path between the AC I/F circuit and the relay. In this example, terminating circuits 901, 902, 903 and 904 are provided in electrical paths between each of the AC I/F circuits 801, 802, 803 and 804 and each of the relays RE1, RE2, RE3 and RE4, respectively. Incidentally, each AC I/F circuit 801, 802, 803, 804 may include a corresponding termination circuit 901, 902, 903, 904. FIG.

FIG. 8 is an explanatory diagram of the configuration of termination circuits 901 , 902 , 903 and 904 . Termination circuits 901, 902, 903 and 904 each have the same basic configuration. Therefore, here, the basic configuration of one termination circuit (referred to as termination circuit 900) will be described.

The termination circuit 900 includes a discharge switching section 950 and a switching drive section 970 . FIG. 8 shows, as an example of the discharge switching unit 950, a configuration in which a solid relay 951 and a shunt resistor 952 for discharging residual charges are connected to the AC inputs (L** and N_*) of the AC I/F circuit. showing things. The switching drive unit 970 is a drive circuit that switches the solid relay 951 on and off. The "discharge section" mainly corresponds to the discharge switching section 950, but the switching drive section 970 may be included in the "discharge section".

where L** refers to L1A, L2A, L3A, L1B, L2C, and L3D, and N_* refers to N_A, N_B, N_C, and N_D. Since the AC I/F circuit 801 has three phases (L1A, L2A, L3A) supplied, there are three sets in total, one for the combination of L1A-N_A, the combination of L2A-N_A, and the combination of L3A-N_A. A discharge switching unit 950 is provided. That is, the residual charge is discharged for each of the first, second, and third phase circuits. Since the AC I/F circuits 802 to 804 are of the single-phase two-wire system, they each have one set of discharge switching units 950 . As for the switching driver 970, each of the AC I/F circuits 801-804 has one set.

Also, the DMON signal is a common signal that is supplied to each switching drive section 970 .

The potential on the L** line side of the shunt resistor 952 is binarized by the comparator 953 . That is, the comparator 953 outputs High when the level of the residual potential detected from the L** line side is equal to or higher than the threshold value set in the comparator 953, and Low when the level is lower than the threshold value. As the door is opened, the potential on the L** line side rises, the TL signal becomes High immediately after the door is opened, and the TL signal becomes Low when the residual potential falls below the threshold value due to discharge. In other words, the comparator 953, as a "comparator", compares the residual voltage level of the AC I/F circuit with a dangerous voltage level that is equal to or lower than the dangerous voltage that is the set voltage level.

A hysteresis comparator is used as the comparator 953 because the comparator 953 may contain an AC component. It should be noted that a filter that cuts AC components through experiments may be used. The TL signal binarized and output by the comparator 953 is input to the logic circuit Z (see FIG. 11).

Note that the shunt resistor 952 can employ a cement resistor or the like having a sufficient rated current.

The switching driving section 970 is a driving circuit that switches ON/OFF of the discharge by the discharge switching section 950 . In the example shown in FIG. 8, the switching drive unit 970 switches the solid relay 951 on and off. The switching drive section 970 drives the solid relay drive C2 according to the level of the DMON signal input from the interlock switch detection circuit 1000. FIG.

The DMON signal becomes Low when even one of the two doors is open, and becomes High when both of the two doors are closed. When the DMON signal is Low, the transistor Tr2 is turned off, current flows through the solid relay drive C2 through the resistor R1, and the solid relay 951 is turned on. That is, when the solid relay 951 is turned on, the shunt resistor 952 is connected between the AC inputs L** and N_* of the AC I/F circuit, and the residual charge of the AC I/F circuit is discharged.

On the other hand, when the DMON signal is High, the transistor Tr2 is turned on, the solid relay drive C2 is turned off, and the solid relay 951 is switched off. That is, the shunt resistor 952 connected between L** and N_* is disconnected.

Note that the power supply V2 shown in FIG. 8 may be a power supply different from the power supply V1 used in the interlock section 511 shown in FIG. For example, the power source V2 is assumed to be a secondary battery or a capacitor power source so that it is always supplied separately from the power source V1. It is assumed that the secondary battery or capacitor power supply is charged while the power supply V1 of the main body is on.

The interlock switch detection circuit 1000 is shown together with the interlock sections 511 and 512 as an example of an "interlock section", and outputs a DMON signal as an example of a "switching signal" output by the "interlock section". Interlock switch detection circuit 1000 logically operates contacts (DUAL contacts) of two interlock sections 511 and 512 by AND 600 and outputs a High or Low DMON signal to switching drive section 970 . For the DUAL contacts of the interlock parts 511 and 512, contacts different from those shown in FIG.

Here, if it is necessary to comply with the requirements of the international standard ISO13849, it may be changed to a highly reliable interlock switch or a safety relay for monitoring the operation of the main breaker M1. Also, the DUAL contact was used as an example, but when the DUAL contact must be used in accordance with ISO 13849, it may be determined as appropriate whether to use it in a multiplexed manner or to prepare a separate contact.

FIG. 9 is a diagram illustrating an example of setting the threshold value of the comparator 953. In FIG. FIG. 9(a) shows changes in the residual voltage of the system power supply input unit 51 after the door is opened. The change is shown with the vertical axis representing the residual voltage and the horizontal axis representing the elapsed time. Since the main breaker is turned off by the interlock mechanism when the door is opened, the residual voltage of each AC I/F circuit of the distribution destination decreases with the lapse of time. The three curves respectively show changes in the residual voltages of the three-phase motor, servomotor, controller, and AMP. The controller and the AMP show similar changes, so they are shown as one curve.

Here, in the safety standards such as IEC60204-1 of the International Electrotechnical Commission, the standard of time to reduce the voltage to below the hazardous voltage is within 5 seconds. The residual voltage decreases as shown in FIG. 9(a), but according to general discharge characteristics, the residual voltage decreases more slowly when the load is heavy.

Ink jet printers have a wide variety of AC I/F circuits, and the circuits are complicated. Therefore, the speed at which the residual voltage drops differs depending on the load difference in each AC I/F circuit. Therefore, there are also local areas where the speed at which the residual voltage decreases slows down. In addition, when the AC I/F circuit has an abnormality or failure, it is not known whether the residual voltage will drop in the same curve as when it is normal. can not cut.

Also, the value of the dangerous voltage (dangerous voltage threshold) shown in FIG. 9(a) is uniquely determined. Even if this value is satisfied, some people may experience considerable numbness or discomfort.

FIG. 9B is a diagram showing setting of the threshold value of the comparator 953. As shown in FIG. As mentioned above, hazardous voltages defined by safety standards are not completely safe. As shown in FIG. 9(b), the comparator threshold is set at a voltage value lower than the danger voltage threshold.

The comparator threshold or set voltage level may be any voltage below the danger voltage threshold or danger voltage level. For example, if there are no areas where discharge is slow locally in the target inkjet printer, the discharge characteristics are verified in advance, and the comparator threshold is set to a low voltage obtained by adding a safety factor to the dangerous voltage. In this case, the comparator threshold may be set close to the dangerous voltage depending on the magnitude of the safety factor. The safety factor may be determined as appropriate. For example, it may be appropriately determined with a value that considers individual differences, a value that assumes a child, or the like. Thus, depending on the size of the safety factor, the comparator threshold may be set to a lower value.

As described above, by setting the threshold of the comparator at a voltage value lower than the dangerous voltage, it is possible to reliably detect that the voltage has become lower than the dangerous voltage.

(Configuration of LED)
FIG. 10 is a diagram showing an example of an arrangement of LED lights. FIG. 10 shows housings for doors 500-1 and 500-2. Switchboards 51-1 and 51-2 of the system power supply input unit 51 are configured respectively. The depth of the housing portion is about 150 mm, and the red LED light LD1 and the white LED light LD2 are arranged in the housing portion. The red LED light LD1 corresponds to a "warning light" that lights up to warn of danger, and the white LED light LD2 corresponds to a "safety light" that indicates safety. The white LED light LD2 also serves as an illumination lamp for facilitating work.

For example, the red LED light LD1 may be used to dimly illuminate the entire switchboard. Arranged on the front side of LD1. The white LED light LD2 may be tilted in the direction of illuminating the parts of the switchboard.

FIG. 11 is a diagram showing an example of a lighting circuit for the red LED light LD1 and the white LED light LD2. Here, the lighting circuit is an example of a "warning output section" that outputs a "warning signal". In this example, a red LED light LD1 and a white LED light LD2 are included in the warning output section. The lighting circuit 1100 shown in FIG. 11 outputs a drive control signal LEDC1 as a "warning signal" and a "warning cancellation signal" from the logic circuit Z to switch the lighting of the red LED light LD1. Further, the lighting circuit 1100 outputs the drive control signal LEDC2 as a "warning signal" and a "warning cancellation signal" from the logic circuit Z to switch the lighting of the white LED light LD2.

Logic circuit Z performs a logical operation on the input of the TL signal output from comparator 953 and the DMON signal output from AND 600 of interlock switch detection circuit 1000, and generates a "warning signal" and a "warning cancel signal" based on the operation result. , and switches the lighting of the red LED light LD1 and the white LED light LD2. Since there are six discharge switching units 950 shown in FIG. The logic circuit Z generates a drive control signal LEDC1 and a drive control signal LEDC2 for the red LED light LD1 and the white LED light LD2, respectively, as an operation result, and inputs them to the transistors Tr11 and Tr12, respectively.

When the drive control signal LEDC1 is High, the transistor Tr11 is turned on, and the red LED light LD1 is lit by current flowing from the power supply V2 through the resistor R12. On the other hand, when the drive control signal LEDC1 is Low, the voltage drops to Low level through the resistor R11, turning off the transistor Tr11. That is, the red LED light LD1 is extinguished without current flow.

Also, when the drive control signal LEDC2 is High, the transistor Tr12 is turned on, and the white LED light LD2 is lit by current flowing from the power supply V2 through the resistor R14. On the other hand, when the drive control signal LEDC2 is Low, the voltage drops to Low level through the resistor R13, turning off the transistor Tr12. In other words, the white LED light LD2 is extinguished without current flow.

Here, as an example of the lighting circuit 1100, the configuration of one transistor is shown, but if a large current is required to increase the illuminance of the LED light, it may be replaced with an appropriate drive circuit.

(Operation of logic circuit)
12A and 12B are explanatory diagrams of the operation of the logic circuit Z. FIG. With reference to FIG. 12, the operation of the logic circuit Z during the period from when the door is opened until when the door is closed will be described. A logic circuit Z receives a DMON signal and six TL signals. Any TL signal is High when the residual voltage is equal to or higher than the threshold, and therefore High is input immediately after the door is opened. Also, when the residual voltage falls below the threshold with the lapse of time, the comparator 953 outputs Low and becomes a Low input.

FIG. 12 shows the input pattern of the TL signal that drops below the set voltage fastest among the six TL signals and the input pattern of the TL signal that drops below the set voltage latest. The input pattern of each TL signal is High input immediately after the door is opened. Therefore, the timing at which the TL signal becomes Low is different.

When the residual voltages of all AC I/F circuits are below the threshold, all TL signals will output Low. Therefore, the red LED light LD1, which is the meaning of warning, lights up when the warning signal is output until the voltage drops to the set voltage where all TL signals output Low immediately after the door is opened, and turns off when the voltage drops below the set voltage. do. The white LED light LD2 is turned on after the red LED light LD1 is turned off.

In FIG. 12, the logic circuit Z detects opening and closing of the door with the DMON signal. After the door is opened, the logic circuit Z continues to output the driving control signal LEDC1 for the red LED light LD1 at High until all TL signals become Low. Further, when all the TL signals become Low, the drive control signal LEDC1 is switched to Low and output. In addition, the logic circuit Z continues to output the drive control signal LEDC2 of the white LED light LD2 at Low when the TL signal is High, and switches the drive control signal LEDC2 to High when all the TL signals become Low. do. The DMON signal becomes High when one door is open and becomes Low when both doors are closed. It outputs the signal LEDC1 and the drive control signal LEDC2, and outputs the drive control signal LEDC1 and the drive control signal LEDC2 at Low when the DMON signal is Low.

In this embodiment, the red LED light LD1 is turned on until the set voltage is less than the dangerous voltage, and when the set voltage is less than the dangerous voltage, the red LED light LD1 is switched to the white LED light LD2. Although an example of switching has been shown, the present invention is not limited to this. For example, only the red LED light LD1 is provided, the red LED light LD1 is turned on until the set voltage is equal to or lower than the dangerous voltage, and the red LED light LD1 is turned off when the set voltage is equal to or lower than the dangerous voltage. may be Alternatively, only the white LED light LD2 may be provided, and the white LED light LD2 may be turned on when the set voltage is equal to or lower than the dangerous voltage.

Also, although an example has been shown in which the user is informed whether or not the voltage is below the dangerous voltage by turning on the LED light, means other than the LED light may be used. For example, it may be notified whether or not the voltage is below the dangerous voltage by a sound such as a buzzer or by displaying a warning screen. In any case, by using a warning signal such as the drive control signal LEDC1 and the drive control signal LEDC2, the user can check whether the voltage is below the dangerous voltage or not.

As described above, when the door is opened, the user can be notified whether the voltage has dropped to a dangerous voltage specified by the safety standard or a voltage that is safer than the safety standard. work can be done.

(Modification 1)
In the embodiment, an example in which common red and white LED lights are provided for each of the door 500-1 and the door 500-2 is shown. and white LED lights may be provided.

FIG. 13 is a diagram showing an example of the arrangement of LED lights according to Modification 1. As shown in FIG. As shown in FIG. 13, a red LED light LD1 and a white LED light LD2 are arranged in the accommodation portions of the doors 500-1 and 500-2, respectively. Here, on the door 500-1 side, the red LED light LD11 and the white LED light LD12 correspond to the red LED light LD1 and the white LED light LD2, and on the door 500-2 side, the red LED light LD21 and A white LED light LD22 corresponds to the red LED light LD1 and the white LED light LD2.

FIGS. 14 and 15 are diagrams for explaining the circuit configuration when a red LED light LD1 and a white LED light LD2 are provided in the accommodation portions of the doors 500-1 and 500-2, respectively. As shown in FIG. 14, the open/close detection signals DMON1 and DMON2 outputted from the interlock section 511 and the interlock section 512 are inputted to the logic circuit Z as shown in FIG.

The signal of DMON1 becomes Low when the door 500-1 is opened, and becomes High when the door 500-1 is closed. The DMON2 signal becomes Low when the door 500-2 is opened, and becomes High when the door 500-2 is closed.

Further, as shown in FIG. 15, as lighting circuits, a lighting circuit 2001 and a lighting circuit 2002 for a red LED light LD11 and a white LED light LD12 on the door 500-1 side, and a red LED light on the door 500-2 side. A lighting circuit 2003 and a lighting circuit 2004 for the light LD21 and the white LED light LD22 are provided.

Logic circuit Z receives six TL signals and two open/closed detection signals (DMON1 and DMON2), and based on the results of their calculations, drives control signals LEDC1, LEDC2, LEDC3 and LEDC4 are output. For example, the lighting circuit having the configuration shown in FIG. 11 can be used. When the drive control signal is High, the transistor Tr is turned on and the LED light is lit. On the other hand, when the drive control signal is Low, the transistor Tr is turned off and the LED light is extinguished.

That is, the logic circuit Z detects opening/closing of the door 500-1 with DMON1, and detects opening/closing of the door 500-2 with DMON2. For example, after the door 500-1 is opened, the logic circuit Z continues to output the drive control signal LEDC1 for the red LED light LD1 at High until all the TL signals of the switchboard housed in the door 500-1 become Low. . Further, when all the TL signals become Low, the drive control signal LEDC1 is switched to Low and output. In addition, the logic circuit Z continues to output the drive control signal LEDC2 of the white LED light LD2 at Low when even one of those TL signals is High, and when all of those TL signals become Low, the drive control signal LEDC2 is switched to High for output. Door 500-2 operates independently in the same manner.

(Modification 2)
In the embodiment, an example was shown in which the residual charge of each AC I/F circuit is discharged by using the termination circuit. Since the discharge may be slow in some cases, here, as a modified example 2, a structure that enhances the discharge effect after a predetermined time has passed since the door is opened will be described.

16 and 17 are explanatory diagrams of the configuration according to Modification 2. FIG. FIG. 16 is a diagram showing an example of a basic configuration of a termination circuit 900 according to Modification 2. As shown in FIG. FIG. 16 shows an example in which resistors are connected in parallel to enhance the discharge effect. Note that this configuration is an example, and is not limited to this. In addition, as long as it is a configuration that enhances the discharge effect, it may be applied as appropriate.

As shown in FIG. 16, in the termination circuit 900, a shunt resistor 952 is a first shunt resistor, and a second shunt resistor 956 is provided in parallel with the first shunt resistor 952 as a configuration for enhancing the discharge effect. . A second shunt resistor 956 switches connections with a solid relay 955 connected in series with the second shunt resistor 956 .

FIG. 17 is an explanatory diagram of the logic circuit Z according to Modification 2. As shown in FIG. Logic circuit Z incorporates a timer. Logic circuit Z runs a timer when the DMON signal goes high, and when the count value of the timer reaches a preset set time (for example, a value indicating 10 seconds, which is double the safety standard), the residual voltage is higher than the set voltage level. A SHUNTC signal is output to the termination circuit 900 to switch the discharge speed of the AC I/F circuit to a higher speed. Although it depends on the threshold value, if the residual voltage does not fall below the threshold value for a period of time longer than the safety standard, an abnormality or failure may occur. Therefore, at a predetermined time, the SHUNTC signal is output from the logic circuit Z to drive the solid relay 955 . As a result, the solid relay 955 connects the shunt resistor 956 between the AC input L** and N_* of the AC I/F circuit to speed up the discharging of the residual charge of the AC I/F circuit.

Solid relay 955 is driven by the SHUNTC signal from logic circuit Z by applying a relay that can be driven by logic circuit Z, as shown in FIG. Alternatively, a solid relay drive may be provided in the termination circuit 900 and driven by the SHUNTC signal from the logic circuit Z. FIG. In addition, a drive circuit configured as shown in switching drive section 970 may be provided in termination circuit 900 as a drive circuit corresponding to solid relay 955 . A SHUNTC signal is input to the transistor Tr of the drive circuit corresponding to the solid relay 955 .

FIG. 18 is a diagram illustrating an example of setting the threshold value of the comparator 953. In FIG. Similar to FIG. 9, FIG. 18 shows changes in the residual voltages of the three-phase motor, servomotor, controller, and AMP. The count-up is started from the opening of the door shown in FIG. 18, and the set count-up value enhances the discharge effect of the three-phase motor.

Although FIG. 18 expresses the three-phase motor with one curve, the first, second, and third phases have different curves. Therefore, not only the difference in discharge time between a three-phase motor and a non-three-phase motor, but also the discharge time in each phase in a three-phase motor may differ. Therefore, the threshold level TL of each phase may be individually monitored by a timer, and the SHUNT signal may be output only to the terminating circuit corresponding to the timed-out phase.

Also, if the time does not expire even after a long period of time has passed, it can be said to be a failure, although it is not a major failure. In this case, the red LED continues to illuminate and does not switch to the white LED, so the user can determine that there is a failure.

As described above, the discharging effect is enhanced at the set count-up value, thereby increasing the speed of reduction of the residual voltage from the count-up value. Further, when switching to a setting that enhances the discharge effect, a threshold value (Th2) lower than the threshold value (Th1) of the comparator 953 when not switching can be provided.

(Modification 3)
In Modified Example 3, a configuration will be described in which a test operation of turning on the LED light is performed at the start of work without operating the door. The inkjet printer is provided with a start button, and when the printer is in operation, it is started by the start button, and the controller board 10 appropriately closes the relays RE1, RE2, RE3, and RE4 to control the entire apparatus. In Modification 3, in order to perform the test operation of lighting the LED light without starting with the start button, it has a test function unit, and a push switch is provided as an "input unit" for instructing the start of the test. . By turning on the main switch M1 and turning on the push switch, the test function unit performs a lighting test operation. Since the door 500 is not opened in the test operation, the interlock does not operate and the main breaker B1 remains on.

19 and 20 are explanatory diagrams of the configuration according to Modification 3. FIG. 19 and 20 show the main configuration of the test function section. 19 is a diagram illustrating an example of a configuration of a relay driving circuit according to Modification 3. FIG. FIG. 19 shows one unit configuration of a relay drive circuit for various relays. One or more relays are driven by resistor R1, resistor R2, transistor Tr3 (Tr), and relay drive.

In Modified Example 3, the relay drive circuit is provided with a transistor Tr4 for switching ON/OFF of the transistor Tr3. The transistor Tr4 test-drives the transistor Tr3 by the test signal (TESTDR*) from the logic circuit Z. FIG. When the test signal is Low, the transistor Tr4 is turned off and the transistor Tr3 is turned off. When the test signal is High, the transistor Tr4 is turned on and the transistor Tr3 is turned on.

FIG. 20 is a diagram showing an example of input/output in logic circuit Z. In FIG. Logic circuit Z has an additional input from push switch SW5. Further, in the logic circuit Z, drive outputs (TESTDR1 to TESTDR4) of the transistor Tr4 are added as a "test signal output section".

A push signal is input to the logic circuit Z when the main switch M1 is turned on and the push switch SW5 for test start is pushed. When the push signal is input, the logic circuit Z performs the following internal operations assuming that the DMON signal for when the door is opened is virtually input as the DMON signal.

First, the logic circuit Z outputs TESTDR1-4 to the relay drive circuits of the relays RE1-RE4 for a short period of time to turn on the relays RE1-RE4 for a short period of time. Each of the relays RE1 to RE4 is driven by the controller board 10, and by driving the transistor Tr4 in this manner, each of the relays RE1 to RE4 can be turned on. During this time, logic circuit Z does not output LEDC1 and LEDC2.

Logic circuit Z monitors the signal and turns on the LED when a predetermined operation is performed. In the event of an error, another LED may be turned on, or may be made to blink.

For example, the logic circuit Z turns on the relay that turns off the main breaker with the output of TESTDR*, and further turns on the solid relay 951 that turns on the termination circuit 900 with the output of TESTDR*. Logic circuit Z then monitors the TL signals, and if any one of the TL signals is not below the threshold voltage of the comparator, the red LED light LD1 is turned on at LEDC1. Then, when all the TL signals become equal to or lower than the dangerous voltage equal to or lower than the threshold of the comparator, LEDC1 turns off the red LED light LD1, and LEDC2 turns on the white LED light LD2. From the above, it can be confirmed that the shunt resistance works and the LED light can be driven.

In the present embodiment and each of the modified examples, the configuration of the power supply unit has been described in detail using an inkjet printer as an example, but the present invention is not limited to liquid ejection apparatuses such as inkjet printers. Any electronic device that includes at least one AC I/F circuit is included in the object.

Although some embodiments and modifications of the present invention have been described above, these embodiments and modifications are presented as examples and are not intended to limit the scope of the invention. These novel embodiments and modifications can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. Each of these embodiments and modifications are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

1 inkjet printer 10 controller board 11 operation panel 20 scanning mechanism 30 ink supply unit 40 transport mechanism 50 power supply unit 51 system power supply input unit 52 inlet 500, 500-1, 500-2 door 511, 512 interlock 801, 802, 803, 804 AC I/F circuit 811 drive unit 900, 901, 902, 903, 904 termination circuit (discharge unit)
950 discharge switching unit 951 solid relay 952 shunt resistor 953 comparator 970 switching drive unit 1000 interlock switch detection circuit 1100 lighting circuit B1 main breaker C1 coil K1 interlock mechanism RE1, RE2, RE3, RE4, RE5, RE6 relay LD1 red LED Light LD2 White LED light M1 Main switch SW1 Shunt switch Z Logic circuit

JP-A-11-234816 JP-A-2000-276984

Claims (9)

an interlock unit that outputs a switching signal in conjunction with the opening operation of the door of the power supply unit;
a cutoff switching unit that switches a power breaker that cuts off the power supply unit from an external power supply that supplies power to the power supply unit to cut off power based on the output of the switching signal by the opening operation;
a discharge unit that discharges electric charges remaining in a circuit included in the power supply unit that is separated from the external power supply by the power breaker based on the output of the switching signal by the opening operation;
a comparator that compares the residual voltage level of the circuit with a set voltage level that is equal to or lower than the dangerous voltage;
a warning output unit for outputting a warning signal until the residual voltage level in the comparison unit is reduced to at least the set voltage level;
electronic equipment. The power supply unit has, as the circuit, an AC circuit that operates by receiving a three-phase AC power supply from the external power supply,
The discharge unit discharges electric charges remaining in each of the AC circuits of the first phase, the second phase, and the third phase of the three-phase AC power supply,
The warning output unit outputs a warning signal until each residual voltage of each AC circuit in the comparison unit drops to at least the set voltage level.
The electronic device according to claim 1. The power supply unit further includes, as the circuit, a single-phase AC circuit obtained by dividing the three-phase power supplied from the external power supply into a single phase,
The discharging unit further discharges the electric charge remaining in the single-phase AC circuit,
The warning output unit outputs a warning signal until each residual voltage of the single-phase AC circuit in the comparison unit drops to at least the set voltage level.
The electronic device according to claim 2. The warning output unit outputs a warning cancellation signal after each residual voltage level has decreased to the set voltage level, and turns on a warning light according to the warning signal, turns on a safety light according to the warning cancellation signal, or after lighting the warning light by the warning signal, switching lighting to the safety light by the warning cancellation signal;
The electronic device according to any one of claims 1 to 3. a plurality of said doors;
the warning light and the safety light common to a plurality of the doors;
The electronic device according to claim 4. a plurality of said doors;
Each door has a pair of the warning light and the safety light,
The warning output unit outputs a warning signal to the warning light on the side of the door until the residual voltage level of the circuit included in the side of the door that has performed the opening operation decreases to at least the set voltage level, and the opening operation is performed. outputting a warning cancellation signal to the safety light on the door side after the residual voltage level of the circuit included in the door side has decreased to the set voltage level;
The electronic device according to claim 4. The discharging unit further performs switching to increase the discharge speed of the circuit where the residual voltage level is higher than the set voltage level when a set time elapses before the residual voltage level decreases to the set voltage level.
The electronic device according to any one of claims 1-6. further comprising a test function unit that performs a test operation with the door closed,
The test function unit
an input unit for inputting a test start instruction;
In response to the input of the start instruction, the controller turns on the relay that is turned on after the electronic device is started by the test signal, instructs the switching of the power breaker by the test signal, and tests the discharge of the residual charge of the circuit by the discharge unit. a test signal output unit instructed by a signal;
has
the comparison section compares the residual voltage level and the set voltage level based on the operation of the test signal output section;
The warning output unit outputs a warning signal until the residual voltage level drops to at least the set voltage level.
The electronic device according to any one of claims 1 to 7. a liquid ejection unit that ejects liquid onto a recording medium;
a power supply unit for the liquid ejection unit;
The power supply unit
an interlock unit that outputs a switching signal in conjunction with the opening operation of the door of the power supply unit;
a cutoff switching unit that switches a power breaker that cuts off the power supply unit from an external power supply that supplies power to the power supply unit to a power cutoff state based on the output of the switching signal by the opening operation;
a discharge unit that discharges electric charges remaining in a circuit included in the power supply unit cut off by the power breaker based on the output of the switching signal by the opening operation;
a comparator that compares the residual voltage level of the circuit with a set voltage level that is equal to or lower than the dangerous voltage;
a warning output unit for outputting a warning signal until the residual voltage level in the comparison unit is reduced to at least the set voltage level;
a liquid ejection device.

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