JP5917032B2 - Ink jet recording apparatus and wiring method thereof - Google Patents

Description

  The present invention relates to an ink jet recording apparatus provided with a recording head for performing recording using thermal energy and a wiring method thereof.

  The ink jet recording method is a method of recording an image by discharging a liquid (for example, ink) from a discharge port of a recording head and attaching it to a recording medium such as paper. In this ink jet recording system, high-quality and high-speed recording is possible by ejecting the liquid by utilizing the foaming of the liquid generated by the heat energy from the heating element provided in the recording head.

  The ink droplets attached to the recording medium spread on the recording medium to form dots. An image is formed on the recording medium as an aggregate of the dots. The area of one dot depends on the size of the ink droplet, that is, the ink ejection amount. For this reason, it is important to control the ink discharge amount in order to record an image with high image quality using an inkjet recording apparatus.

  Even if the same thermal energy is generated by applying the same drive pulse to the heating element, the ink ejection amount changes depending on the temperature of the ink around the heating element. Therefore, the ink jet recording apparatus employs a configuration in which a temperature sensor is provided in the recording head for the purpose of managing the ink temperature (see, for example, Patent Document 1).

  FIG. 2 is a block diagram illustrating a configuration example of a general inkjet recording apparatus.

  As shown in FIG. 2, the ink jet recording apparatus includes a control circuit unit 101, a head unit 102, a main scanning motor 103, a sub scanning motor 104, an operation unit 105, and an interface (I / F) unit 106.

  The ink jet recording apparatus records an image on a recording medium in accordance with a recording signal including image data and commands transmitted from the host device 107. The host device 107 is an information processing device such as a computer, a digital camera, or a scanner that can transmit and receive information to and from the inkjet recording device.

  The control circuit unit 101 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and a motor driver for driving the main scanning motor 103 and the sub-scanning motor 104. The control circuit unit 101 controls the operation of each unit of the inkjet recording apparatus by executing processing according to a predetermined control program stored in the ROM by the CPU. The RAM is used to temporarily hold a recording signal transmitted from the host device 107.

  The head unit 102 includes the above-described temperature sensor and recording head, and records an image on a recording medium by ejecting ink in accordance with an instruction from the control circuit unit 101.

  The main scanning motor 103 is a motor for moving the head unit 102 in the main scanning direction with respect to the recording medium. The sub-scanning motor 104 is a motor for moving the recording medium in the sub-scanning direction that is the transport direction.

  The operation unit 105 includes a power switch and various control switches, and is used by a user to input necessary commands and the like to the ink jet recording apparatus.

  The interface unit 106 is a communication interface for transmitting and receiving information to and from the host device 107 and receives the recording signal transmitted from the host device 107. Further, the interface unit 106 transmits the status information of the inkjet recording apparatus output from the control circuit unit 101 to the host device 107 as necessary.

  Incidentally, since the head unit 102 is a movable unit that moves in the main scanning direction as described above, it is necessary to connect the head unit 102 and the control circuit unit 101 with a wiring member that does not hinder the movement. Therefore, an FFC (flexible flat cable) is usually used as a wiring member that connects the head unit 102 and the control circuit unit 101.

  FIGS. 3A and 3B are diagrams illustrating an example of connection between the head unit and the control circuit unit illustrated in FIG. 1. FIG. 3A is a connection diagram, and FIG. 3B is a cross-sectional view of connection wiring. FIG. 3B shows a state in which the FFC conductor connecting the head unit 102 and the control circuit unit 101 is viewed from the direction of the arrow in FIG.

  As shown in FIG. 3A, signals transmitted and received between the head unit 102 and the control circuit unit 101 include a head power supply VH and ground potential GND for supplying required power to the recording head, and the above-described temperature. Sensor output signal. Since the head power source VH and the ground potential GND are used as power sources for heating elements that boil the ink when ink is ejected, a large current flows. Therefore, the FFC is usually provided with a plurality of head power lines and ground potential lines (GND lines) as shown in FIG.

  On the other hand, a weak current signal is output from the temperature sensor. Therefore, the FFC is provided with a temperature sensor line for an output signal of the temperature sensor, for example, corresponding to each type of ink. FIG. 3A shows an example in which two temperature sensor lines are provided corresponding to two types of ink.

  Thus, the FFC includes a head power line and a GND line through which a relatively large current flows, and a temperature sensor line through which a weak current flows. Therefore, when a magnetic field is generated by a large current flowing through the head power supply line and the GND line, an induced current flows through the temperature sensor line due to the magnetic field and is superimposed as noise on the output signal of the temperature sensor.

  As shown in FIG. 3A, when ink is ejected, a current flows from the control circuit portion 101 to the head portion 102 through the head power supply line VH as shown by the arrows in the figure. Further, a return current flows from the head unit 102 toward the control circuit unit 101 through the GND line as indicated by an arrow in the figure. At this time, a magnetic field as shown in FIG. 3B is generated in each head power line and GND line. Furthermore, when currents in the same direction flow through a plurality of head power lines provided adjacent to each other, a strong magnetic field is generated by synergizing the magnetic fields generated in the head power lines. Similarly, when currents in the same direction flow through a plurality of GND lines provided adjacent to each other, the magnetic fields generated in the GND lines are combined to generate a strong magnetic field. In that case, an induced current flows in the temperature sensor line arranged near the head power line or the GND line due to the magnetic field generated in the head power line or the GND line, and appears as noise in the output signal of the temperature sensor.

  Therefore, Patent Document 2 proposes an algorithm for estimating the temperature of the head unit 102 in consideration that the output signal of the temperature sensor transmitted from the head unit 102 is not reliable due to the influence of noise.

  3A and 3B, only the head power supply VH, the ground potential GND, and the output signal of the temperature sensor are shown as signals transmitted and received between the head unit 102 and the control circuit unit 101. There are also many other control signals. FIG. 4 shows an example of signal arrangement of the background art FFC including these control signals.

  FIG. 4 is a table showing an example of signal arrangement in the FFC included in the background art ink jet recording apparatus.

  As shown in FIG. 4, the FFC is composed of, for example, three layers of CN301, CN302, and CN303. The head power line and the GND line are provided in the CN302 and CN303 layers, and the temperature sensor line is provided in the CN302 layer. . The temperature sensor line is assigned to a conductor near the center of the CN 302 layer, and a plurality of GND lines and a head power line are arranged adjacent to the temperature sensor line. FIG. 4 shows an example in which a head power source A and a head power source B, GND_A and GND_B, and a temperature sensor A and a temperature sensor B are provided as the head power source, GND, and temperature sensor. Head power supply A, GND_A and temperature sensor A indicate signal lines used for color ink, for example. Head power supply B, GND_B and temperature sensor B indicate signal lines used for black ink, for example. Yes.

  In the signal arrangement shown in FIG. 4, when ink is ejected, magnetic fields are generated in the head power supply A line and the head power supply B line, and the GND_A line and the GND_B line, respectively, as shown in FIG. Furthermore, when currents in the same direction flow through a plurality of head power supply A lines and head power supply B lines provided adjacent to each other, a strong magnetic field is generated by synergizing the magnetic fields generated in the head power supply lines. Similarly, when currents in the same direction flow through a plurality of GND_A lines and GND_B lines provided adjacent to each other, the magnetic fields generated in the GND lines are combined to generate a strong magnetic field. Therefore, an induced current flows in the temperature sensor lines (A and B) arranged in the vicinity of the head power line and the GND line due to the magnetic field generated in the head power line and the GND line, and noise is generated in the output signal of the temperature sensor. Appears as In addition, when a control signal through which a weak current flows is arranged not only in the temperature sensor line but in the vicinity of the head power supply line or the GND line, noise is generated in the control signal as in the temperature sensor line. End up.

JP-A-5-31905 JP 7-125216 A

  As described above, in the inkjet recording apparatus of the background art, the head power supply line and the GND line through which a relatively large current flows and the temperature sensor line through which a weak current flows through the FFC connecting the head unit and the control circuit unit. Are mixed. Therefore, there is a problem that an induced current flows through the temperature sensor line due to a magnetic field generated by the head power supply line or the GND line and is superimposed as noise on the output signal of the temperature sensor.

  In order to cope with such a problem, for example, when an algorithm for estimating the temperature of the head part described in Patent Document 2 is adopted, the control of the entire inkjet recording apparatus by the control circuit part becomes complicated. Therefore, there is a possibility that a new defect may occur due to the complexity. Therefore, in order to accurately grasp the temperature of the head part, it is desirable to reduce the induction noise generated by the current flowing through the above-described head power supply line and GND line.

  The present invention has been made to solve the above-described problems of the background art, and an ink jet recording apparatus and a wiring method thereof that can reduce noise generated in a signal transmitted and received between a head unit and a control circuit unit. The purpose is to provide.

In order to achieve the above object, an ink jet recording apparatus of the present invention comprises a recording head for discharging a liquid and a head portion comprising a temperature sensor for detecting the temperature of the recording head,
A control circuit unit for controlling ejection of the liquid from the recording head;
Said first and second power supply lines and first and second ground potential line for supplying required power to the recording head, the temperature sensor line for transmitting and receiving an output signal of the previous SL temperature sensor, and the recording A wiring member for connecting the head unit and the control circuit unit, including a control signal line for supplying a signal for controlling the head;
An inkjet recording apparatus comprising:
The wiring member includes first and second wiring layers,
The temperature sensor line, the first power supply line, the first ground potential line, the second power supply line, and the second ground potential line are provided in this order in the first wiring layer. ,
In the second wiring layer, a third power supply line, a third ground potential line, a fourth power supply line, and a fourth ground potential line are arranged adjacently in this order,
With respect to the stacking direction of the first and second wiring layers, the temperature sensor line and the control signal line are provided at overlapping positions .

On the other hand, the wiring method of the ink jet recording apparatus of the present invention includes a recording head for discharging a liquid and a head portion including a temperature sensor for detecting the temperature of the recording head;
A control circuit unit for controlling ejection of the liquid from the recording head;
A wiring method for connecting the head unit and the control circuit unit of an inkjet recording apparatus having:
First and second power supply lines and first and second ground potential lines for supplying required power to the recording head to a wiring member connecting the head unit and the control circuit unit, and the temperature sensor A temperature sensor line for transmitting and receiving an output signal , and a control signal line for supplying a signal for controlling the recording head ,
The wiring member includes first and second wiring layers,
In the first wiring layer, the temperature sensor line, the first power supply line, the first ground potential line, the second power supply line, and the second ground potential line are arranged in this order,
A third power supply line, a third ground potential line, a fourth power supply line, and a fourth ground potential line are arranged adjacent to each other in this order in the second wiring layer,
In the stacking direction of the first and second wiring layers, the temperature sensor line and the control signal line are arranged at overlapping positions .

  ADVANTAGE OF THE INVENTION According to this invention, the noise which generate | occur | produces in the signal transmitted / received between a head part and a control circuit part can be reduced.

It is a table figure which shows the example of signal arrangement | positioning in FFC with which the inkjet recording device of this invention is provided. It is a block diagram which shows the structural example of a general inkjet recording device. FIG. 3 is a diagram illustrating an example of connection between the head unit and the control circuit unit illustrated in FIG. 2, in which (a) is a connection diagram, and (b) is a cross-sectional view of connection wiring. It is a table figure which shows the example of signal arrangement | positioning in FFC with which the inkjet recording device of background art is provided. It is a schematic diagram which shows a mode that a magnetic field generate | occur | produces in the example of arrangement | positioning shown in FIG.

  Next, the present invention will be described with reference to the drawings.

  The configuration of the ink jet recording apparatus of the present embodiment is the same as that of the background art shown in FIG.

  As shown in FIG. 2, the ink jet recording apparatus includes a control circuit unit 101, a head unit 102, a main scanning motor 103, a sub scanning motor 104, an operation unit 105, and an interface (I / F) unit 106.

  The ink jet recording apparatus records an image on a recording medium in accordance with a recording signal including image data and commands transmitted from the host device 107. The host device 107 is an information processing device such as a computer, a digital camera, or a scanner that can transmit and receive information to and from the inkjet recording device.

  The control circuit unit 101 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and a motor driver for driving the main scanning motor 103 and the sub-scanning motor 104. The control circuit unit 101 controls the operation of each unit of the inkjet recording apparatus by executing processing according to a predetermined control program stored in the ROM by the CPU. The RAM is used to temporarily hold a recording signal transmitted from the host device 107.

  The head unit 102 includes the above-described temperature sensor and recording head, and records an image on a recording medium by ejecting ink in accordance with an instruction from the control circuit unit 101.

  The main scanning motor 103 is a motor for moving the head unit 102 in the main scanning direction with respect to the recording medium. The sub-scanning motor 104 is a motor for moving the recording medium in the sub-scanning direction that is the transport direction.

  The operation unit 105 includes a power switch and various control switches, and is used by a user to input necessary commands and the like to the ink jet recording apparatus.

  The interface unit 106 is a communication interface for transmitting and receiving information to and from the host device 107 and receives the recording signal transmitted from the host device 107. Further, the interface unit 106 transmits the status information of the inkjet recording apparatus output from the control circuit unit 101 to the host device 107 as necessary.

  In such a configuration, the control circuit unit 101 drives the sub-scanning motor 104 to move the recording medium to a predetermined printing position when an image recording (printing) instruction is issued from the host device 107. The control circuit unit 101 performs recording by ejecting ink from the head unit 102 in accordance with a recording signal while driving the main scanning motor 103 to move the head unit 102 in the main scanning direction. In addition, the control circuit unit 101 detects the temperature around the recording head using a temperature sensor, and adjusts the voltage and width of the drive pulse supplied to each heating element according to the temperature. When the recording for one line in the main scanning direction is completed, the control circuit unit 101 drives the sub-scanning motor 104 to move the recording medium to the next recording position. By repeatedly executing the above processing, the image instructed from the host device 107 is recorded on the recording medium.

  As described above, since the head unit 102 is a movable unit that moves in the main scanning direction, the head unit 102 and the control circuit unit 101 need to be connected by a wiring member that does not interfere with movement. Therefore, an FFC (flexible flat cable) is used as a wiring member that connects the head unit 102 and the control circuit unit 101.

  FIG. 1 is a table showing an example of signal arrangement in the FFC included in the inkjet recording apparatus of the present invention.

  As shown in FIG. 1, in the inkjet recording apparatus of the present embodiment, the FFC that connects the head unit 102 and the control circuit unit 101 is composed of three layers of CN301, CN302, and CN303, as in the background art shown in FIG. It is configured. Signals transmitted and received between the head unit 102 and the control circuit unit 101 include a plurality of head power sources VH and ground potential GND for supplying required power to the recording head, and the output signal of the temperature sensor described above. . The head power supply line and the ground potential line (GND line) are provided in the CN302 and CN303 layers, and the temperature sensor line is provided in the CN302. If the current capacity of the conductor provided in the FFC is sufficiently large, the head power supply line and the GND line may each be one.

  In the present embodiment, a plurality of head power lines and a plurality of GND lines are alternately arranged in the CN 302 and CN 303 layers, respectively. Specifically, the head power supply A line and the GND_A line are alternately arranged in the CN302 layer, and the head power supply B line and the GND_B line are alternately arranged in the CN303 layer. The head power supply A, GND_A, and the temperature sensor A indicate signal lines used for color ink, for example, as in the background art, and the head power supply B, GND_B, and temperature sensor B for black ink, for example. The signal line used is shown.

  When the head power supply lines and the GND lines are alternately arranged in this way, the direction of the current flowing when ink is ejected is different for each adjacent signal line, and the direction of the magnetic field generated by the current flowing through these signal lines is also adjacent. Different for each signal line. Therefore, unlike the background art, magnetic fields generated by a plurality of signal lines provided adjacent to each other do not synergize and become a strong magnetic field. Therefore, it is possible to reduce the influence of a magnetic field that a signal line through which a weak signal such as a temperature sensor line receives from the head power supply line or the GND line.

  Furthermore, in the present embodiment, the temperature sensor line is assigned to the conductor at the end of the CN302 layer, and is arranged at a position away from the head power supply line and the GND line where a strong magnetic field is generated. By disposing the head power line and the GND line away from each other as described above, the influence of the magnetic field received from the head power line and the GND line by a signal line through which a weak signal such as a temperature sensor line can be further reduced.

  According to this embodiment, the noise generated in the temperature sensor line can be reduced by alternately arranging the head power supply line and the GND line in the FFC connecting the head unit 102 and the control circuit unit 101. Furthermore, by disposing the temperature sensor line away from the head power supply line and the GND line, the influence of the magnetic field received from the head power supply line and the GND line can be further reduced. Therefore, since the temperature of the recording head can be detected more accurately by the temperature sensor, the ink discharge amount from the recording head can be optimally controlled.

DESCRIPTION OF SYMBOLS 101 Control circuit part 102 Head part 103 Main scanning motor 104 Sub operation motor 105 Operation part 106 Interface part 107 Host apparatus

Claims (7)

A head unit comprising a recording head for discharging liquid and a temperature sensor for detecting the temperature of the recording head;
A control circuit unit for controlling ejection of the liquid from the recording head;
Said first and second power supply lines and first and second ground potential line for supplying required power to the recording head, the temperature sensor line for transmitting and receiving an output signal of the previous SL temperature sensor, and the recording A wiring member for connecting the head unit and the control circuit unit, including a control signal line for supplying a signal for controlling the head;
An inkjet recording apparatus comprising:
The wiring member includes first and second wiring layers,
The temperature sensor line, the first power supply line, the first ground potential line, the second power supply line, and the second ground potential line are provided in this order in the first wiring layer. ,
In the second wiring layer, a third power supply line, a third ground potential line, a fourth power supply line, and a fourth ground potential line are arranged adjacently in this order,
An ink jet recording apparatus provided at a position where the temperature sensor line and the control signal line overlap with each other in the stacking direction of the first and second wiring layers . 2. The ink jet recording apparatus according to claim 1 , wherein the temperature sensor line, the first and second power supply lines, and the first and second ground potential lines are arranged with another signal line interposed therebetween. . With respect to the stacking direction of the first and second wiring layers, the first power supply line and the third ground potential line are arranged to overlap each other, and the first ground potential line and the third ground potential line are arranged. The ink jet recording apparatus according to claim 1 , wherein the ink jet recording apparatus is disposed at a position where the power line overlaps. With respect to the stacking direction of the first and second wiring layers, the second power supply line and the fourth ground potential line are arranged to overlap each other, and the second ground potential line and the fourth ground potential line are arranged. The ink jet recording apparatus according to claim 1 , wherein the ink jet recording apparatus is disposed at a position where the power line overlaps. A stacking direction of the first and second wiring layers, any one of claims 1 to 4 is disposed at a position not overlapping with the wiring for the temperature sensor lines to supply the required power to the recording head 2. An ink jet recording apparatus according to item 1. A head unit comprising a recording head for discharging liquid and a temperature sensor for detecting the temperature of the recording head;
A control circuit unit for controlling ejection of the liquid from the recording head;
A wiring method for connecting the head unit and the control circuit unit of an inkjet recording apparatus having:
First and second power supply lines and first and second ground potential lines for supplying required power to the recording head to a wiring member connecting the head unit and the control circuit unit, and the temperature sensor A temperature sensor line for transmitting and receiving an output signal , and a control signal line for supplying a signal for controlling the recording head ,
The wiring member includes first and second wiring layers,
In the first wiring layer, the temperature sensor line, the first power supply line, the first ground potential line, the second power supply line, and the second ground potential line are arranged in this order,
A third power supply line, a third ground potential line, a fourth power supply line, and a fourth ground potential line are arranged adjacent to each other in this order in the second wiring layer,
A wiring method of an ink jet recording apparatus , wherein the temperature sensor line and the control signal line are arranged at an overlapping position with respect to a stacking direction of the first and second wiring layers . The inkjet recording apparatus according to claim 6, wherein the temperature sensor line, the first and second power supply lines, and the first and second ground potential lines are arranged with another signal line interposed therebetween. Wiring method.