JP2010206903A - Fan motor connecting circuit and liquid-drop ejector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a fan motor connecting circuit that suppresses the occurrence of nonconformities caused by the generation of an inrush current without causing increase in the cost and size, and to provide a liquid-drop ejector. <P>SOLUTION: The fan motor connection circuit disconnects a power supply connecting line L1 for supplying a drive power to fan motors 73 connected to the downstream side, until fan motors 73 connected to the upstream side are normally driven by transistors Q1-Q4 that are respectively interposed in between a plurality of the fan motors 73 so as to mutually daisy-chain-connect each fan motor 73, and the fan motor connecting circuit connects the power supply connecting line L1, after the fan motors connected to the upstream side are driven in a normal manner. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fan / motor connection circuit and a droplet discharge device, and in particular, a supply terminal to which driving power is supplied and a driving state output for outputting a state detection signal indicating whether or not the driving is normal. The present invention relates to a fan motor connection circuit that connects a plurality of fan motors having terminals, and a droplet discharge device that uses the plurality of fan motors to dry a recording medium on which an image is formed by droplets.

  2. Related Art There is known a droplet discharge device that forms an image on a recording medium by a set of dots formed by the droplets by discharging the droplets by an inkjet printing method or the like. In this type of droplet discharge device, there is one that dries a recording medium on which an image is formed using a plurality of fan motors.

  By the way, in addition to a supply terminal for supplying driving power to the fan motor, a driving state for outputting a state detection signal indicating whether or not the fan motor is operating normally Some have an output terminal. The state detection signal is sometimes referred to as a lock signal, a lock detection signal, a fan lock detection signal, an abnormality detection signal, or the like, but is expressed here as a state detection signal.

  As a technique related to the connection of each fan motor when using a plurality of fan motors having this type of drive state output terminal, Patent Document 1 discloses a connection method for connecting a plurality of fans to the control side. Two electric wires for power supplied to each fan are connected in parallel to form two common electric wires for electric power, and a logical sum signal of abnormality detection signals output from each fan is generated to generate one electric wire. A technique is disclosed in which the plurality of fans and the control side are electrically connected with a total of three electric wires as signal outputs.

  FIG. 8 shows an example of a fan / motor connection circuit to which this technique is applied.

  As shown in the figure, this fan motor connection circuit includes connectors CN1 to CN5 that are individually connected to a plurality of fan motors (not shown) (five fan motors in the example shown in the figure). Is provided.

  The five fan motors are provided with three terminals: a supply terminal (two terminals for voltage application and grounding) for supplying driving power, and a driving state output terminal. Corresponding to one terminal, each connector CN1 to CN5 is provided with three connection terminals of a first pin, a second pin, and a third pin.

  Here, as for each connection terminal in each of the connectors CN1 to CN5, the 1st pin corresponds to the fan / motor voltage application terminal, the 2nd pin corresponds to the fan / motor drive state output terminal, and the 3rd pin Corresponds to the ground terminal of the fan / motor.

  As shown in the figure, in this fan / motor connection circuit, each fan / motor is connected in parallel to a power supply connected as a power supply source to the voltage application terminal DC_IN and the ground terminal GND. The fan motor connection circuit is provided with transistors Q1 to Q5 having an open collector configuration corresponding to each fan motor, and the drive state output terminal of each fan motor is It is connected to any one of the corresponding transistors Q1 to Q5 via any one of the corresponding connectors CN1 to CN5.

  The collectors of the transistors Q1 to Q5 are wired or connected and are pulled up via the resistor R6 and connected to the state detection terminal SD.

  As shown in the figure, the bases of the transistors Q1 to Q5 are pulled up by any one of the corresponding resistors R1 to R5. In addition, a connection for applying a power supply voltage to each fan / motor via the first pin of each of the connectors CN1 to CN5 has an open / close control terminal connected to the switch control terminal SW1_ON, and a switch SW1 for interrupting the connection. A fuse FU1 for protecting each element of the fan / motor connection circuit is interposed.

  The state detection terminal SD and the switch control terminal SW1_ON are connected to a control unit (not shown). The control unit can detect the driving state of the fan / motor and can control the opening / closing operation of the switch SW1. .

  In this fan / motor connection circuit, when a power supply voltage is applied between the first and third pins of the connectors CN1 to CN5, each fan / motor is started.

  At this time, the state detection signal input from the second pin of each of the connectors CN1 to CN5 shifts from the high impedance state before the start of the fan motor to the low level during normal operation, so that each of the transistors Q1 to Q5. Since the state detection terminal SD is pulled up by the resistor R6, the state detection terminal SD has a high level indicating that all fan motors are normally driven. A signal is output.

  Here, when at least one of the fan motor is in an abnormal state, the state detection signal output from the fan motor is in a high impedance state, and the corresponding transistor is turned on. As a result, the state detection signal is output from the state detection terminal SD. The signal being transferred goes from high level to low level.

  Therefore, the control unit can determine that at least one of the fan motor is in an abnormal state when the state detection terminal SD shifts to a low level.

JP 2007-46511 A

  By the way, when a plurality of fans and motors are simultaneously activated by a fan / motor connection circuit as shown in FIG. 8 as an example, the activation currents of the respective fans and motors are overlapped, and a large current (inrush current) flows temporarily. In this case, the rated current value of the protective fuse (the fuse FU1 in the example shown in FIG. 8) set by the current value during normal operation exceeds the rated current value. Due to the voltage drop caused by exceeding the current capacity due to the occurrence of the inrush current, malfunctions of other circuits may be induced, or elements located in the power supply path may be destroyed. There was a problem that there was.

  In order to deal with this problem, as shown in FIG. 9 as an example, the fans and motors are divided into a plurality of groups (two groups in the example shown in the figure), and each group is started with a time difference. Although a method is also conceivable, in this case, there is a problem that a plurality of lines for power supply connections, switches, and the like are required, resulting in an increase in cost and an increase in size.

  The present invention has been made to solve the above-described problems, and a fan-motor connection circuit capable of suppressing the occurrence of problems due to the occurrence of inrush current without causing an increase in cost or an increase in size, and An object is to provide a droplet discharge device.

  In order to achieve the above object, the fan-motor connection circuit according to claim 1 outputs a supply terminal to which driving power is supplied and a state detection signal indicating whether or not the driving is normally performed. A power supply connection for supplying the driving power to the supply terminals of a plurality of fan motors having status output terminals, and a daisy chain connection between the fan motors interposed between the plurality of fan motors In addition, based on the state detection signal output from the drive state output terminal of the fan motor connected to the upstream side, the downstream side until the fan motor connected to the upstream side is normally driven. Cut the power supply connection for supplying the driving power to the fan motor connected to the side, and connect the power supply connection after being driven normally Also it includes a single switching element.

  According to the fan-motor connection circuit according to claim 1, a plurality of drive terminals having a supply terminal to which drive power is supplied and a drive state output terminal for outputting a state detection signal indicating whether or not the drive is normally operated. The driving power is supplied to the supply terminal of the fan motor by power supply connection.

  Here, in the present invention, the drive state output of the fan motor connected upstream by at least one switch element interposed between the plurality of fan motors and daisy chain connecting the fan motors. Based on the state detection signal output from the terminal, the driving power is supplied to the fan motor connected to the downstream side until the fan motor connected to the upstream side is normally driven. For this reason, the power supply connection is cut and the power supply connection is connected after being driven normally.

  Accordingly, in the present invention, since the fan motor connected to the upstream side is normally driven and then the power supply to the fan motor connected to the downstream side is started, a plurality of fan motors are started simultaneously. As a result, it is possible to suppress the occurrence of defects due to the occurrence of inrush current.

  In the present invention, since all the fans and motors are daisy-chain connected, the fan and motors are divided into a plurality of groups and start up with a time difference for each group. There is nothing.

  Thus, according to the fan motor connection circuit of claim 1, the fan connected to the upstream side by the switch element that is interposed between the plurality of fan motors and daisy chain connects the fan motors. -Disconnect the power supply connection for supplying drive power to the fan motor connected downstream until the motor is driven normally, and connect the power supply connection after it is driven normally. Therefore, it is possible to suppress the occurrence of defects due to the occurrence of inrush current without increasing the cost or increasing the size.

  According to the present invention, as in the invention described in claim 2, the switch element is connected to the drive state output terminal of the fan motor having an open / close control terminal connected to the upstream side. A connection terminal may be interposed in the power supply connection for supplying the driving power to the fan motor connected to the downstream side.

  In the present invention, the switch element may be a transistor or a relay switch. The transistor includes a bipolar transistor and a field effect transistor.

  Further, according to the present invention, as in the invention described in claim 4, after the fan motor connected to the upstream side is normally driven, the fan motor connected to the downstream side is driven for driving. There may be further provided a delay circuit for delaying the timing of connecting the power supply connection for supplying the power. As a result, the start timing of each fan / motor can be shifted more reliably, so that it is possible to more reliably suppress the occurrence of problems due to the occurrence of inrush current.

  On the other hand, in order to achieve the above object, a droplet discharge device according to a fifth aspect includes a fan / motor connection circuit according to any one of the first to fourth aspects and the fan / motor connection circuit. A plurality of connected fan motors, a forming unit for forming an image indicated by the image information on the recording medium by discharging droplets on the recording medium based on the image information, and an image formed by the forming unit Drying means for drying the formed recording medium using the plurality of fan motors.

  Therefore, according to the present invention, a recording medium on which an image is formed by droplets is dried by a plurality of fan motors that are provided with the fan motor connection circuit of the present invention and are connected by the fan motor connection circuit. Similarly to the fan-motor connection circuit of the present invention, it is possible to suppress the occurrence of problems due to the occurrence of inrush current without increasing the cost or increasing the size.

  According to the present invention, the switching element interposed between the plurality of fans and motors daisy-chains each fan motor to the downstream side until the fan motor connected to the upstream side is normally driven. The power supply connection for supplying driving power to the connected fan motor is cut, and the power supply connection is connected after it is driven normally, so there is no increase in cost or size. Thus, an effect that it is possible to suppress the occurrence of defects due to the occurrence of inrush current can be obtained.

1 is a cross-sectional side view illustrating a configuration of an image forming apparatus according to an embodiment. 1 is a schematic perspective view illustrating a configuration of a hot air nozzle provided in an image forming apparatus according to an embodiment. It is a circuit diagram which shows the structure of the fan motor connection circuit which concerns on embodiment. 1 is a block diagram illustrating a system configuration of an image forming apparatus according to an embodiment. It is a flowchart which shows the flow of a process of the fan motor drive processing program which concerns on embodiment. It is a circuit diagram which shows the other structural example of the fan motor connection circuit which concerns on embodiment. It is a circuit diagram which shows the other structural example of the fan motor connection circuit which concerns on embodiment. It is a circuit diagram which shows the structural example of the conventional fan motor connection circuit. It is a circuit diagram which shows the other structural example of the conventional fan motor connection circuit.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, a case where the present invention is applied to a so-called inkjet printer (hereinafter referred to as “image forming apparatus”) that forms an image with ink droplets will be described.

  First, the overall configuration of the image forming apparatus 10 according to the present embodiment will be described.

[Image forming apparatus]
As shown in FIG. 1, the image forming apparatus 10 according to the present exemplary embodiment includes a sheet feeding unit that feeds and conveys a sheet upstream of a sheet as a recording medium (hereinafter referred to as “sheet”). A transport unit 12 is provided. On the downstream side of the paper feeding / conveying unit 12, a processing liquid application unit 14 that applies a processing liquid to the recording surface (image forming surface) of the paper along the paper conveyance direction, and an image is formed on the recording surface of the paper. An image forming unit 16, an ink drying unit 18 for drying the image formed on the recording surface, an image fixing unit 20 for fixing the dried image on the paper, and a discharge unit 21 for discharging the paper on which the image is fixed are provided.

  Hereinafter, each processing unit will be described.

(Paper feed section)
The paper feeding / conveying unit 12 is provided with a stacking unit 22 on which sheets are stacked, and on the downstream side of the stacking unit 22 in the sheet conveying direction (hereinafter, “sheet conveying direction” may be omitted). A paper feeding unit 24 is provided for feeding the papers stacked on the stacking unit 22 one by one. The sheet fed by the sheet feeding unit 24 is conveyed to the processing liquid coating unit 14 through a conveying unit 28 constituted by a plurality of pairs of rollers 26.

(Processing liquid application part)
In the treatment liquid application unit 14, a treatment liquid application drum 30 is rotatably disposed. The processing liquid coating drum 30 is provided with a holding member 32 that holds the paper by sandwiching the leading end of the paper, and the paper is held on the surface of the processing liquid coating drum 30 via the holding member 32. In this state, the sheet is conveyed downstream by the rotation of the treatment liquid coating drum 30.

  Note that an intermediate conveying drum 34, an image forming drum 36, an ink drying drum 38, and a fixing drum 40, which will be described later, are also provided with a holding member 32 in the same manner as the processing liquid coating drum 30. The holding member 32 transfers the paper from the upstream drum to the downstream drum.

  A processing liquid coating device 42 and a processing liquid drying device 44 are disposed above the processing liquid coating drum 30 along the circumferential direction of the processing liquid coating drum 30. The treatment liquid is applied to the surface, and the treatment liquid is dried by the treatment liquid drying device 44.

  Here, the treatment liquid reacts with the ink to aggregate the color material (pigment) and has an effect of promoting separation of the color material (pigment) and the solvent. The treatment liquid application device 42 is provided with a storage portion 46 for storing the treatment liquid, and a part of the gravure roller 48 is immersed in the treatment liquid.

  A rubber roller 50 is disposed in pressure contact with the gravure roller 48, and the rubber roller 50 contacts the recording surface (front surface) side of the paper to apply the processing liquid. Further, a squeegee (not shown) is in contact with the gravure roller 48 to control the amount of treatment liquid applied to the recording surface of the paper.

  Ideally, the treatment liquid film thickness is sufficiently smaller than the droplets of the head droplets. For example, when the droplet volume is 2 pl, the average diameter of the droplets of the head droplet is 15.6 μm, and when the treatment liquid film thickness is thick, the ink dots float in the treatment liquid without contacting the recording surface of the paper. To do. In order to obtain a landing dot diameter of 30 μm or more with a droplet ejection amount of 2 pl, it is preferable to make the treatment liquid film thickness 3 μm or less.

  On the other hand, in the treatment liquid drying device 44, a hot air nozzle 54 and an infrared heater 56 (hereinafter referred to as “IR heater 56”) are disposed in proximity to the surface of the treatment liquid application drum 30. A solvent such as water in the processing liquid is evaporated by the hot air nozzle 54 and the IR heater 56 to form a solid or thin film processing liquid layer on the recording surface side of the paper. By thinning the treatment liquid in the treatment liquid drying step, the dots deposited by ink in the image forming unit 16 come into contact with the surface of the paper to obtain the required dot diameter, and react with the thinned treatment liquid. It is easy to obtain an action of agglomerating color materials and fixing to the paper surface.

  In this way, the paper on which the processing liquid has been applied and dried on the recording surface by the processing liquid application unit 14 is conveyed to an intermediate conveyance unit 58 provided between the processing liquid application unit 14 and the image forming unit 16.

(Intermediate transport section)
The intermediate transport drum 58 is rotatably provided in the intermediate transport unit 58, and a sheet is held on the surface of the intermediate transport drum 34 via a holding member 32 provided in the intermediate transport drum 34, and the intermediate transport drum 34 The sheet is conveyed downstream by the rotation of 34.

(Image forming part)
An image forming drum 36 is rotatably provided in the image forming unit 16, and a sheet is held on the surface of the image forming drum 36 via a holding member 32 provided on the image forming drum 36. The sheet is conveyed downstream by the rotation of 36.

  A single-pass inkjet line head 64 (hereinafter referred to as “head”) in which a plurality of nozzles for ejecting ink droplets are two-dimensionally provided near the surface of the image forming drum 36 at the top of the image forming drum 36. 64 ”) is provided. In this head unit 66, at least basic colors Y (yellow), M (magenta), C (cyan), and K (black) heads 64 are arranged along the circumferential direction of the image forming drum 36 to apply the treatment liquid. The image of each color is formed on the processing liquid layer formed on the recording surface of the sheet by the unit 14.

  The treatment liquid has the effect of aggregating the color material (pigment) and latex particles dispersed in the ink into the treatment liquid, and forms an aggregate that does not generate color material flow on the paper. As an example of the reaction between the ink and the treatment liquid, acid is contained in the treatment liquid, pigment dispersion is destroyed by PH down, and the color material bleeds using a mechanism of aggregation, color mixing between each color ink, liquid mixture at the time of ink droplet landing Avoids droplet-interference caused by

  The head 64 performs droplet ejection in synchronism with an encoder (not shown) that detects the rotational speed disposed on the image forming drum 36, thereby determining the landing position with high accuracy, as well as vibration of the image forming drum 36, It is possible to reduce droplet ejection spots regardless of the accuracy of the rotating shaft 68 and the drum surface speed.

  The head unit 66 can be retracted from the upper part of the image forming drum 36, and maintenance operations such as cleaning the nozzle surface of the head 64 and discharging the thickened ink are retracted from the upper part of the image forming drum 36. It is carried out by letting.

  The sheet on which the image is formed on the recording surface is conveyed to an intermediate conveyance unit 70 provided between the image forming unit 16 and the ink drying unit 18 by the rotation of the image forming drum 36. Since the configuration is substantially the same as that of the intermediate conveyance unit 58, description thereof is omitted.

(Ink drying section)
An ink drying drum 38 is rotatably provided in the ink drying unit 18, and a plurality of hot air nozzles 72 and IR heaters 74 are arranged above the ink drying drum 38 in the vicinity of the surface of the ink drying drum 38. It is installed. With the hot air from the hot air nozzle 72 and the IR heater 74, the solvent separated by the color material aggregating action is dried in the paper image forming unit, and a thin image layer is formed.

  The hot air is usually set to 50 ° C. to 70 ° C., although it varies depending on the sheet conveyance speed. The evaporated solvent is discharged together with air to the outside of the image forming apparatus 10, but the air is recovered. This air may be cooled by a cooler / radiator or the like and recovered as a liquid.

  The sheet on which the image on the recording surface is dried is conveyed to an intermediate conveyance unit 76 provided between the ink drying unit 18 and the image fixing unit 20 by the rotation of the ink drying drum 38. Since the configuration is substantially the same as that of the intermediate conveyance unit 58, description thereof is omitted.

(Image fixing part)
An image fixing drum 40 is rotatably provided in the image fixing unit 20. In the image fixing unit 20, latex particles in a thin image layer formed on the ink drying drum 38 are heated / pressurized. And has a function of fixing and fixing on the paper.

  A heating roller 78 is disposed above the image fixing drum 40 in the vicinity of the surface of the image fixing drum 40. The heating roller 78 has a halogen lamp incorporated in a metal pipe made of aluminum or the like having a good thermal conductivity. The heating roller 78 applies heat energy equal to or higher than the Tg temperature of the latex. As a result, the latex particles are melted and pressed into the irregularities on the paper for fixing, and the irregularities on the image surface are leveled to obtain glossiness.

  A fixing roller 80 is provided on the downstream side of the heating roller 78. The fixing roller 80 is disposed in pressure contact with the surface of the image fixing drum 40 so as to obtain a nip force with the image fixing drum 40. Therefore, at least one of the fixing roller 80 and the image fixing drum 40 has an elastic layer on the surface and a uniform nip width with respect to the paper.

  The sheet on which the image on the recording surface is fixed by the above-described process is conveyed to the discharge unit 21 side provided on the downstream side of the image fixing unit 20 by the rotation of the image fixing drum 40.

  In this embodiment, the image fixing unit 20 has been described. However, the image fixing unit 20 is not necessarily required because it is sufficient that the image formed on the recording surface can be dried and fixed by the ink drying unit 18. .

(Hot air nozzle in ink drying section)
Here, the configuration of the hot air nozzle 72 provided in the ink drying unit 18 that is particularly related to the present invention will be described. As shown in FIG. 1, in the image forming apparatus 10 according to the present embodiment, a plurality of hot air nozzles 72 are applied, all of which have the same configuration.

  As shown in FIG. 2, the hot air nozzle 72 according to the present embodiment has a plurality (eight in this embodiment) of fans that blow air toward the image forming surface of the paper conveyed by the ink drying drum 38. 72A and a plurality (two in this embodiment) of IR heaters 72B for heating the air blown by each fan 72A.

  Here, the hot air nozzle 72 according to the present embodiment is a slit whose side close to the surface of the ink drying drum 38 (the lower side in the figure) is inclined in a taper shape in cross section and whose leading end is long in the paper width direction. A plurality of fans 72A are arranged in the paper width direction in the opened portion. On the other hand, the plurality of IR heaters 72B are provided inside the casing 72D.

  With this configuration, the hot air nozzle 72 is efficiently heated by the IR heater 72B with the air blown by the fans 72A, and the heated air is intensively blown onto the image forming surface of the paper through the opening 72C.

  Although not shown in the drawing, each fan 72A has a motor (hereinafter referred to as “fan motor”) 73 in which the rotation center of the corresponding fan 72A is attached to the rotation shaft (see FIG. 3). Are individually provided, and each fan 72 </ b> A is rotated by driving a corresponding fan motor 73.

[Fan motor connection circuit]
Next, a configuration of the fan / motor connection circuit 71 according to the present embodiment, which is a connection circuit of each fan / motor 73, will be described with reference to FIG. In order to avoid complications, a case where the number of fan motors 73 is five will be described here.

  As shown in the figure, the fan / motor connection circuit 71 according to the present embodiment is provided with a plurality of connectors CN1 to CN5 that are individually connected to the plurality of fan motors 73, respectively. In the figure, only one fan motor 73 is shown, and the other fan motors 73 are not shown.

  As shown in the figure, each fan motor 73 is normally driven with a supply terminal (two terminals for voltage application and grounding) for supplying driving power to the fan motor 73. Are provided with a drive state output terminal for outputting a state detection signal indicating whether or not the connector is connected. Corresponding to these three terminals, each connector CN1 to CN5 has a first pin and a second pin. , And three connection terminals of the third pin are provided.

  In each connector CN1 to CN5, the first pin is connected to the voltage application terminal of the fan motor 73, the second pin is connected to the drive state output terminal of the fan motor 73, and the third pin is The fan motor 73 is connected to the grounding terminal.

  As shown in the figure, the fan / motor connection circuit 71 is provided with power supply connections L 1 and L 2 for supplying driving power to the supply terminals of the respective fan / motors 73. The power supply connection L1 is a wiring for applying a predetermined voltage (24V in the present embodiment) on the high voltage side to each fan motor 73, and a voltage application terminal to which the predetermined voltage is applied to one end. DC_IN is provided. The power supply connection L2 is a wiring for grounding the grounding terminal of each fan / motor 73, and a ground terminal GND is provided at one end.

  Also, the fan motor connection circuit 71 is interposed between the fans and motors 73 to daisy chain the fans and motors 73 and from the drive state output terminal of the fan motor 73 connected upstream. Based on the output state detection signal, power for supplying driving power to the fan motor 73 connected downstream until the fan motor 73 connected upstream is normally driven. Four bipolar transistors (one less than the fan motor 73) bipolar transistors (hereinafter simply referred to as “transistors”) functioning as switch elements for connecting the power supply connection L1 after the supply connection L1 is disconnected and normally driven. Q1 to Q4 are provided.

  Here, the power supply connection L1 is connected to the first pin of the connector CN1 positioned at the most upstream and the emitters of the transistors Q1 to Q4, and the power supply connection L2 is connected to the third pin of each of the connectors CN1 to CN5. And grounded.

  The bases of the transistors Q1 to Q4 are connected to the 2nd pin of any one of the connectors CN1 to CN4 located on the upstream side through any one of the corresponding resistors R1, R3, R5, and R7. The collectors of the transistors Q1 to Q4 are connected to the first pin of any one of the connectors CN2 to CN5 located on the downstream side.

  On the other hand, the base of each transistor Q1-Q4 is pulled up through any one of the corresponding resistors R2, R4, R6, R8, while the second pin of the connector CN5 is routed through the resistor R9. Pulled up and connected to the state detection terminal SD.

  Further, the power supply connection L1 includes a switch SW1 for interrupting the connection between the voltage application terminal DC_IN and the resistor R9, and a fuse FU1 for protecting each element of the fan / motor connection circuit 71. Is intervened.

  The open / close control terminal of the switch SW1 is connected to the switch control terminal SW1_ON.

  As shown in FIG. 1, in the image forming apparatus 10 according to the present embodiment, since a plurality of hot air nozzles 72 are provided in the ink drying unit 18, the fan / motor connection circuit 71 also includes the hot air nozzles 72. There are as many as there are.

[System configuration]
Next, the system configuration of the image forming apparatus 10 according to the present embodiment will be described with reference to FIG.

  As shown in the figure, the image forming apparatus 10 includes a communication interface 83, a system controller 84, an image memory 85, a ROM 86, a motor driver 87, a heater driver 88, a fan / motor driver 81, a print control unit 89, and an image buffer memory. 90, an image processing unit 91, a head driver 92, and the like.

  The communication interface 83 is an interface unit with the host device 99 that is used by a user to instruct the image forming apparatus 10 to form an image. As the communication interface 83, a serial interface such as USB (Universal Serial Bus), IEEE 1394, Ethernet (registered trademark), a wireless network, or a parallel interface such as Centronics can be applied. In this part, a buffer memory (not shown) for speeding up communication may be mounted.

  Image information sent from the host device 99 is taken into the image forming apparatus 10 via the communication interface 83 and temporarily stored in the image memory 85. The image memory 85 is a storage unit that stores image information input via the communication interface 83, and information is read and written through the system controller 84. The image memory 85 is not limited to a memory made of semiconductor elements, and a magnetic medium such as a hard disk may be used.

  The system controller 84 includes a central processing unit (CPU) and its peripheral circuits, and functions as a control device that controls the entire image forming apparatus 10 according to a predetermined program, and also functions as an arithmetic device that performs various calculations. . That is, the system controller 84 controls the communication interface 83, the image memory 85, the motor driver 87, the heater driver 88, the fan / motor driver 81, and the like, and performs communication control with the host device 99, the image memory 85 and the ROM 86. Control signals for controlling the motor 93 and the IR heaters 56, 74, 72B of the paper transport system are generated. In addition to the control signal, image information stored in the image memory 85 is transmitted to the print control unit 89.

  The ROM 86 stores programs executed by the CPU of the system controller 84 and various data necessary for control. The ROM 86 may be a non-rewritable storage unit, but when various types of data are updated as necessary, it is preferable to use a rewritable storage unit such as an EEPROM.

  The image memory 85 is used as a temporary storage area for image information, and is also used as a program development area and a calculation work area for the CPU.

  The motor driver 87 is a driver (drive circuit) that drives the paper transport motor 93 in accordance with an instruction from the system controller 84. The heater driver 88 is a driver that drives the IR heaters 56, 74, and 72B in accordance with instructions from the system controller 84.

  The fan / motor driver 81 is a driver that drives each fan / motor 73 and the fan / motor connection circuit 71 in accordance with an instruction from the system controller 84.

  Here, the voltage application terminal DC_IN, the switch control terminal SW1_ON, the state detection terminal SD, and the ground terminal GND of the fan / motor connection circuit 71 in each hot air nozzle 72 are connected to the fan / motor driver 81, and the system controller 84 , Control of supply of power supply voltage to each fan motor 73 via the voltage application terminal DC_IN and the ground terminal GND, control of opening / closing of the switch SW1 via the switch control terminal SW1_ON, and state detection for each hot air nozzle 72 The driving state of the fan / motor 73 via the terminal SD can be grasped via the fan / motor driver 81.

  On the other hand, the print control unit 89 includes a CPU and its peripheral circuits, and generates an ejection control signal from image information in the image memory 85 in cooperation with the image processing unit 91 under the control of the system controller 84. In addition to performing various processes and corrections for this purpose, the generated ink discharge data is supplied to the head driver 92 to control the discharge drive of the head unit 66.

  The print controller 89 is connected to a ROM 94 that stores programs executed by the CPU of the print controller 89 and various data necessary for control. The ROM 94 may also be a non-rewritable storage means, but when various data are updated as necessary, it is preferable to use a rewritable storage means such as an EEPROM.

  The image processing unit 91 generates dot arrangement data for each ink color from the input image information, and performs halftoning processing on the input image information to determine a high-quality dot position.

  The image processing unit 91 according to the present embodiment uses a binary (from a density conversion process (including UCR process and color conversion) and, if necessary, a pixel number conversion process, a density correction process, and multi-value density data. Alternatively, halftoning processing (intermediate gradation processing) or the like for conversion into dot arrangement data of multi-value) is performed.

  In FIG. 4, the image processing unit 91 is illustrated as being separate from the system controller 84 and the print control unit 89, but for example, the image processing unit 91 is included in the system controller 84 or the print control unit 89. However, you may make it comprise the part.

  The print control unit 89 also generates an ink discharge data generation function for generating ink discharge data (an actuator control signal corresponding to the nozzles of the head 64) based on the dot arrangement data generated by the image processing unit 91, and driving. And a waveform generation function.

  The ink discharge data generated by the ink discharge data generation function is given to the head driver 92, and the ink discharge operation of the head unit 66 is controlled.

  The drive waveform generation function is a function of generating a drive signal waveform for driving the actuator corresponding to each nozzle of the head 64, and the signal (drive waveform) generated by the drive waveform generation function is the head driver 92. To be supplied. The signal generated by the drive waveform generation function may be digital waveform data or an analog voltage signal.

  The print control unit 89 is provided with an image buffer memory 90, and data such as image information and parameters are temporarily stored in the image buffer memory 90 during image information processing in the print control unit 89. In FIG. 4, the image buffer memory 90 is shown in a mode associated with the print control unit 89, but it can also be used as the image memory 85.

  Note that an aspect in which the print control unit 89 and the system controller 84 are integrated to form a single processor is also possible.

  Next, as an operation of the image forming apparatus 10 according to the present exemplary embodiment, an operation when the rotational drive of the fan motor 73 provided in each hot air nozzle 72 by the system controller 84, which is particularly related to the present invention, is controlled. This will be described in detail with reference to FIG. FIG. 5 is a flowchart showing the flow of processing of the fan / motor drive processing program executed by the CPU of the system controller 84 when the timing for drying the paper by each hot air nozzle 72 arrives. In the predetermined area. In addition, here, it is assumed that only one hot air nozzle 72 is controlled in order to avoid complications.

  In step 100 of the figure, the fan / motor driver 81 is controlled to start application of the predetermined voltage (24V in this case) between the voltage application terminal DC_IN of the fan / motor connection circuit 71 and the ground terminal GND. In the next step 102, the fan / motor driver 81 is controlled so that the switch SW1 is turned on (connected state).

  As a result of the above processing, the fan motor connection circuit 71 starts supplying power for driving the fan motor 73 between the first pin and the third pin of the connector CN1, and as a result, the fan connected to the connector CN1. The motor 73 (hereinafter referred to as “the most upstream fan motor”) is started.

  After that, when the operation of the most upstream fan / motor is stabilized, the status detection signal output from the drive status output terminal of the fan / motor is at a level indicating the status of the fan / motor when it is abnormal or before starting (this implementation In this embodiment, the pin 2 of the connector CN1 is also switched to the high level (from the high level) to the level indicating that the fan motor is operating normally (in this embodiment, the low level). As a result of the transition from the level to the low level, the transistor Q1 transitions from the off state to the on state.

  As a result of the transition of the transistor Q1 to the ON state, supply of driving power for the fan motor 73 between the first and third pins of the connector CN2 is started. As a result, the fan motor 73 connected to the connector CN2 is started. Is activated.

  Thereafter, the same operation is sequentially performed up to the fan motor 73 (hereinafter referred to as “the most downstream fan motor”) positioned at the most downstream, and as a result, the most upstream fan motor reaches the most downstream fan motor. Until then, each fan motor 73 is started one by one from the upstream side.

  In the next step 104, the passage of a predetermined period is waited until the most downstream fan motor is driven normally after the processing in step 102 is executed. Information indicating the level of the output signal from the terminal SD (signal indicating the driving state of the most downstream fan motor) is acquired via the fan motor driver 81, and the information indicates that the fan motor 73 is driven normally. It is determined whether or not the most downstream fan motor is normally driven by determining whether or not it is at a predetermined level (in this embodiment, low level). If the determination is affirmative, the routine proceeds to step 108.

  In step 108, it is determined whether or not the timing for ending paper drying by the hot air nozzle 72 has come. If the determination is negative, the process returns to step 106, but the process proceeds to step 112 when the determination is affirmative. .

  In the image forming apparatus 10 according to the present exemplary embodiment, as a timing at which the paper drying by the hot air nozzle 72 is completed, a predetermined period (5 minutes in the present exemplary embodiment) after a series of image forming processes is completed. The timing at which the time has passed is applied, but the present invention is not limited to this timing. Needless to say, other timings such as a timing at which the image forming apparatus 10 shifts to a predetermined operation mode such as an energy saving mode may be applied.

  On the other hand, if a negative determination is made in step 106, the routine proceeds to step 110, where an abnormality handling process that is predetermined to be executed when the fan / motor 73 is abnormal is executed. Transition.

  In the image forming apparatus 10 according to the present embodiment, a process for forcibly stopping the image forming operation is applied as the abnormality handling process. However, the present invention is not limited to this, and in addition to this process, Any one of a process of presenting to the user that an abnormality has occurred in the fan motor 73 by a ringing or a display by a display means, a process of forcibly stopping power supply to the fan motor 73, etc. Needless to say, a plurality of combinations may be applied.

  In step 112, the fan / motor driver 81 is controlled so that the switch SW1 is turned off (disconnected state). -After controlling the motor driver 81, this fan motor drive process program is complete | finished.

  In the fan-motor connection circuit 71 according to the present embodiment, the fan motor 73 in the next stage after the fan motor 73 adjacent to the upstream side stably operates from the most upstream fan motor to the most downstream fan motor. Is activated, the activation currents of the plurality of fan motors 73 do not overlap. Thereby, generation | occurrence | production of the large current at the time of starting can be prevented, and generation | occurrence | production of the blowout of the fuse for protection (in this embodiment, fuse FU1) can be suppressed.

  Further, in the fan / motor connection circuit 71 according to the present embodiment, the driving state output terminals for outputting the state detection signals from the respective fans / motors 73 are connected in cascade, so that the fan / motor 73 in the middle is out of order. The fan / motor 73 in the next stage does not start when the operation is stopped by the above-mentioned operation. Therefore, the operation of each fan / motor 73 can be confirmed by monitoring only the state detection signal of the most downstream fan / motor. it can.

  As described above in detail, in the present embodiment, a switch element (here, a transistor) that is interposed between a plurality of fan motors (here, fan motor 73) and daisy chain connects each fan motor. Power supply connection (here, power supply) for supplying driving power to the fan motor connected to the downstream side until the fan motor connected to the upstream side is normally driven by Q1 to Q4) Since the power supply connection is connected after the supply connection L1) is cut and normally driven, it is possible to suppress the occurrence of problems due to the occurrence of inrush current without increasing the cost or increasing the size. Can do.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various modifications or improvements can be added to the above-described embodiment without departing from the gist of the invention, and embodiments to which such modifications or improvements are added are also included in the technical scope of the present invention.

  The above embodiments do not limit the invention according to the claims (claims), and all the combinations of features described in the embodiments are essential for the solution means of the invention. Is not limited. The embodiments described above include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. Even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, as long as an effect is obtained, a configuration from which these some constituent requirements are deleted can be extracted as an invention.

  For example, in the above-described embodiment, the case where the fan-motor connection circuit of the present invention shown in FIG. 3 is applied has been described. However, the present invention is not limited to this, and for example, shown in FIG. The fan / motor connection circuit 71 ′ may be applied. In FIG. 3, the same components as those in FIG. 3 are denoted by the same reference numerals as those in FIG.

  As shown in the figure, in this fan / motor connection circuit 71 ′, the transition of the corresponding transistors Q1 to Q4 to the ON state is delayed between the bases of the transistors Q1 to Q4 and the ground terminal GND. The only difference from the fan / motor connection circuit 71 according to the above embodiment is that capacitors C1 to C4 are added as delay circuits.

  Therefore, in this case, as compared with the fan / motor connection circuit 71 according to the above-described embodiment, the start timing of each fan / motor can be shifted more reliably. Can be suppressed. In this case, it goes without saying that another delay element such as a delay line can be applied as the delay circuit in place of the capacitor.

  In the above embodiment, the case where the fan-motor connection circuit is configured using the bipolar transistor as the switching element of the present invention has been described. However, the present invention is not limited to this, and FIG. The fan-motor connection circuit 71 ″ may be configured using a field effect transistor as the switch element of the present invention as shown in FIG. In FIG. 7, only the circuit configuration from the most upstream fan motor to the second-stage fan motor 73 is shown, and the third and subsequent stages are not shown.

  As shown in the figure, in the fan / motor connection circuit 71 ″, the power supply connection L1 is connected to the first pin of the connector CN1 and to the source of the field effect transistor F1. Further, the third pins of the connectors CN1, CN2,... Are grounded.

  On the other hand, the fan motor connection circuit 71 ″ is provided with a bipolar transistor Q1 whose base is connected to the second pin of the connector CN1 via a resistor R10, and its emitter via a resistor 12. The collector is grounded while being connected to the gate of the field effect transistor F1. The emitter of the bipolar transistor Q1 is connected to its own base via a resistor R11. The gate of the field effect transistor F1 is pulled up via the resistor 13, while the drain is connected to the first pin of the connector CN2 adjacent to the downstream side.

  In this fan motor connection circuit 71 ″, the field effect transistor F1 functions as a switching element of the present invention, and each fan motor 73 is started in order from the most upstream fan motor to the most downstream fan motor. Become.

  Therefore, it is possible to suppress the occurrence of problems caused by the occurrence of the inrush current also in the fan / motor connection circuit 71 ″.

  In this fan / motor connection circuit 71 ″, as in the fan / motor connection circuit 71 ′ shown in FIG. 6, a capacitor that functions as a delay circuit between the base of the bipolar transistor Q1 and the ground terminal GND is used. Since C1 is interposed, even in this fan / motor connection circuit 71 ″, it is possible to more reliably suppress the occurrence of problems due to the occurrence of the inrush current.

  Moreover, although the case where a transistor was applied as the switch element of the present invention has been described in the above embodiment, the present invention is not limited to this, and for example, a relay switch can be applied. In this case as well, the same effects as in the above embodiment can be obtained.

  In the above-described embodiment, the case where the fan-motor connection circuit of the present invention is applied to a droplet discharge device has been described. However, the present invention is not limited to this, for example, a personal computer, a large computer For example, the fan-motor connection circuit of the present invention may be applied to other electronic devices that use a plurality of fan motors simultaneously. In this case as well, the same effects as in the above embodiment can be obtained.

  In the above embodiment, the case where a so-called single-pass head 64 having a plurality of droplet discharge ports corresponding to the entire width direction of the recording medium is applied as the forming means of the present invention has been described. However, the present invention is not limited to this, and a so-called shuttle scan type head that forms an image while moving in the main scanning direction may be applied as the forming means of the present invention. In this case as well, the same effects as in the above embodiment can be obtained.

  In the above embodiment, the case where the head 64 provided with the two-dimensional droplet discharge port is applied as the forming means of the present invention. However, the present invention is not limited to this. A head in which droplet discharge ports are provided in a one-dimensional shape along the main scanning direction may be applied as the forming means of the present invention. In this case as well, the same effects as in the above embodiment can be obtained.

  In addition, the configuration of the image forming apparatus 10 according to the above-described embodiment (see FIGS. 1 to 4) is an example, and it is needless to say that the configuration can be appropriately changed without departing from the gist of the present invention.

  Furthermore, the processing flow of the fan / motor drive processing program described in the above embodiment (see FIG. 5) is also an example, and the processing order of each step can be changed and processed without departing from the gist of the present invention. Needless to say, it is possible to change the contents, delete unnecessary steps, add new steps, and the like.

10 Image forming apparatus 64 Inkjet line head (formation means)
71, 71 ′, 71 ″ Fan motor connection circuit 72 Hot air nozzle (drying means)
72A Fan 72B Heater 72C Opening 72D Case 73 Fan / Motor 84 System Controller C1-C4 Capacitors (Delay Circuit)
CN1 to CN5 connector F1 field effect transistor (switch element)
FU1 Fuse L1, L2 Power supply connection Q1-Q4 Transistor (switch element)
R1-R13 Resistor SW1 Switch

Claims (5)

The drive power is supplied to the supply terminals of a plurality of fan motors having a supply terminal to which drive power is supplied and a drive state output terminal for outputting a state detection signal indicating whether the drive is normally performed. Power supply connection to supply,
Based on a state detection signal output from the driving state output terminal of the fan motor connected to the upstream side, and daisy chain connecting each fan motor interposed between the plurality of fan motors, Until the fan motor connected to the upstream side is normally driven, the power supply connection for supplying the driving power to the fan motor connected to the downstream side is disconnected and At least one switch element connecting the power supply connection after being driven;
Fan motor connection circuit equipped with The switch element is connected to the drive state output terminal of the fan motor connected to the upstream side of the open / close control terminal, and is connected to the fan motor connected to the downstream side of the connection terminal and the connected terminal for driving. The fan / motor connection circuit according to claim 1, wherein the fan / motor connection circuit is interposed in the power supply connection for supplying the electric power. The fan / motor connection circuit according to claim 1, wherein the switch element is a transistor or a relay switch. Delay the timing of connecting the power supply connection for supplying the driving power to the fan motor connected to the downstream side after the fan motor connected to the upstream side is driven normally The fan motor connection circuit according to any one of claims 1 to 3, further comprising a delay circuit. The fan motor connection circuit according to any one of claims 1 to 4,
A plurality of fan motors connected by the fan motor connection circuit;
Forming means for forming an image indicated by the image information on the recording medium by discharging droplets on the recording medium based on the image information;
A drying unit for drying the recording medium on which an image is formed by the forming unit using the plurality of fan motors;
A droplet discharge device comprising:

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