JP2010052166A - Inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording apparatus including a constitution which can detect disconnection and an increase in the resistance of a flexible flat cable generated at a specified position. <P>SOLUTION: In the inkjet recording apparatus including the flexible flat cable connected with a connector in a one-to-one relation between a carriage substrate and a main substrate, at least signals arranged at both side ends of the flexible flat cable are made to be disconnection detecting signals. The disconnection detecting signal is connected with a power source through a constant electric current power source or a pull-up resistance, and the disconnection detecting signal is connected with an analog port or a port capable of recording the state change of the signal or informing to a CPU, and comprises a means for detecting the state change of the disconnection detecting signal while a print head moves in the main scanning direction or in the sub-scanning direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ink jet printing apparatus that forms an image using a print head in the form of an ink jet print head that ejects ink onto a print medium such as paper.

  An ink jet recording apparatus is composed of a carriage substrate to which an ink jet head for ejecting ink droplets is connected and a main substrate on which a control circuit for controlling the ink droplet ejection operation of the ink jet head is mounted. Considering the ease of assembly and the like, both are configured to be separable. Specifically, a configuration is generally employed in which one end of a flexible flat cable is connected to a carriage substrate connected to the inkjet head, and the other end of the flexible flat cable is connected to a main substrate.

  However, in the connector connection method described above, there is a problem that the connector connection is mistakenly disconnected during the assembly work of the head. Therefore, conventionally, a connector with a lock is often used. This has been desired to be improved because of increased device costs and forgetting to lock.

  On the other hand, for example, a method disclosed in Patent Document 1 is known as an abnormality detection method between electrical circuits or a connection cable for device replacement. Hereinafter, the outline will be described with reference to FIG.

  FIG. 4 is a diagram illustrating a fair example in which abnormality detection is performed with a conventional connection cable. In FIG. 4, the connection cable 401 has one end connected to the circuit board 402 and the other end connected to a circuit board or device (not shown). In the connection cable 401, a plurality of original connection conductors 403 are arranged in parallel, but dummy conductors 404 and 405 are added along both outer edges.

  One end of each of the dummy conductors 404 and 405 is connected to one input end of a comparator 406 and 407 that is a detection circuit provided on the circuit board 402, and the other end of each of the dummy conductors 404 and 405 is a circuit board (not shown). Or connected to ground potential in the device. The comparators 406 and 407 have one input terminal connected to a power source via a resistance element and the other input terminal connected to the ground potential.

  According to this configuration, if there is no disconnection 404 or 105 in the dummy conducting wire, the comparators 406 and 407 set the output to either the H level or the L level. When a break occurs in one or both of the dummy conductors 404 and 405, the corresponding one of the comparators 406 and 407 sets the output to either the H level or the L level. Thereby, disconnection of the connection cable 401 can be detected.

In this example, the disconnection is detected. However, in the case of the ink jet recording apparatus, in addition to the disconnection, a connector connection failure can also be detected.
Japanese Utility Model Publication No. 63-135174

  However, the above method has the following disadvantages.

  In the movement of the main scan and reverse scan of the print head that occurs before complete disconnection, it cannot be detected that the disconnection and the resistance value are increased only at a specific point, and even if disconnection of the disconnection detection signal is detected There was a possibility that the deterioration of the adjacent conductors had begun.

  The present invention has been made in view of the above points, and is an ink jet recording apparatus having a configuration capable of detecting the disconnection of a flexible flat cable occurring at a specific location and a high resistance value, which is a simple configuration. Is possible.

In order to achieve the above object, an ink jet recording apparatus according to the present invention comprises the following arrangement. That is,
An inkjet head having a plurality of ink droplet ejection units for ejecting ink droplets; a carriage substrate on which a connector connected to the inkjet head is mounted; a main substrate for controlling the ink ejection unit and the entire printer; In an inkjet recording apparatus comprising: a flexible flat cable in which a plurality of conductors arranged in parallel on a plane in a one-to-one relationship between the carriage substrate and the main substrate are connected by a connector;
At least one arranged at both ends of the flexible flat cable is used as a disconnection detection signal, the disconnection detection signal is connected to a power source via a constant current power source or a pull-up resistor, and the disconnection detection signal is an analog port or a signal. Means for detecting a change in the state of the previous disconnection detection signal while the print head is moving in the main scanning or backward scanning direction, connected to a port capable of recording or notifying the CPU of the state change;
It is characterized by having.

  According to the present invention, in the main scan and reverse scan movement of the print head that occurs before the complete disconnection starts, it is detected by detecting that the print head has a disconnection and a high resistance value only at a certain point. And cable errors can be identified. Therefore, it is possible to prompt the user to replace the flexible flat cable at an early stage.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

Hereinafter, embodiments of the recording apparatus of the present invention will be described with reference to the drawings. In the embodiments described below, a printer is taken as an example of a recording apparatus using an inkjet recording method.
(Description of inkjet recording apparatus)
(1) Description of Recording Apparatus FIG. 1 is a schematic diagram showing the configuration of an embodiment of an inkjet recording apparatus to which the present invention can be applied. In this figure, 109 is an ink cartridge. These are composed of an ink tank in which four color inks (black, cyan, magenta, and yellow) are respectively placed, and a recording head 108. A paper feed roller 103 and a paper feed roller 103 are rotated in the direction of the arrow in the drawing while holding the print paper 107 together with the auxiliary roller 104 to feed the print paper 107, and the print paper 107 is the same as 103 and 104. It also plays a role in suppressing A carriage 106 supports four ink cartridges, and moves the mounted ink cartridge 109 and recording head 108 together with printing. The carriage 106 is controlled to stand by at the home position indicated by the dotted line in the drawing when the recording apparatus is not printing or when the recovery operation of the recording head is performed.

(2) Description of Recording Head Next, the above-described recording head 108 will be described with reference to FIG. FIG. 2 is a block diagram showing the electrical configuration of the print head. The drive circuit is integrally provided on a substrate (heater board) together with a predetermined number (320 in the figure) of thermal energy generating element groups (discharge heaters R1 to R320). In FIG. 2, reference numerals 201 and 207 denote shift registers as data alignment means in synchronization with serial data (SDATA) in synchronism with the clock (CLK). Data is latched in 206 latch circuits. The latched data 206 is put at one input terminal of the AND gate 208, and heat (HT) is an enable signal for defining the drive (energization) time of the discharge heater, which is also the AND gate. One input of 208 is supplied. Decoded from the block number determined in 203, in the figure, 204 is a transistor array for power supply control as drive means connected to the discharge heater drive power supply (VH) line together with the discharge heaters R1 to R320 for each block, The energization of the discharge heaters R1 to R320 is turned on / off.

(3) Description of Control Configuration FIG. 3 is a configuration example of a control system of the ink jet recording apparatus shown in FIG. In the figure, reference numeral 312 denotes a recording head control circuit for electrically controlling the recording head 108 and discharging ink in accordance with image data. 316 is a main scanning motor that is a driving source for scanning the recording head 106 shown in FIG. 1, 317 is a sub-scanning motor that is a driving source for conveying the print medium 107, and 318 is for operating the recovery processing unit. It is the recovery operation motor which makes the drive source. A mechanism control circuit 321 controls and manages various motors, actuators, and sensors. Reference numeral 322 denotes a ROM that stores a program corresponding to processing means executed by the CPU 315 that controls the overall operation of each unit according to the processing procedure described below. Reference numeral 323 denotes a RAM having an area for temporarily storing parameters in the course of execution of the processing procedure by the CPU 315, and reference numeral 324 denotes a nonvolatile memory such as an EEPROM for storing the discharge detection state even when the apparatus power is turned off. Reference numeral 325 denotes an operation / display unit, which includes a switch for the user to perform a required operation such as power-on, online / offline setting with the host device H, and a display for presenting the device status to the user. . The host device H serves as a supply source of image data to the ink jet recording apparatus. The host device H is a computer for creating and processing data such as images related to printing, as well as a reader unit for image capture, or a digital It may be in the form of a camera or the like. Image data, other commands, status signals, and the like are transmitted and received via an interface (I / F) 326.

  In the configuration of the ink jet recording apparatus described above, the flexible flat cable has a high disconnection and a high resistance value only when the print head is at a specific position in the main scanning and reverse scanning movements of the print head that occur before the complete disconnection starts. A method for detecting this will be described below.

  The overall configuration in the first embodiment will be described. FIG. 5 is a diagram showing an overall configuration of a flexible flat cable connection abnormality detection mechanism provided in the ink jet recording apparatus according to Embodiment 1 of the present invention. As shown in FIG. 5, in the ink jet recording apparatus according to the first embodiment, a carriage substrate 502 to which the ink jet head 501 is connected and a main substrate 503 for controlling the print head are fixed by connectors 505 and 506 with a flexible flat cable 504. The configuration is separable. The inkjet head 501 and the carriage substrate 502 are connected by a pin contact connector 520 and can be separated.

  In the flexible flat cable 504, disconnection detection signals 508 and 509 are arranged along both outer edges. Further, the control signal of the EEPROM 518 and the AD signal of the thermistor for temperature observation are arranged inside, the signal line that does not affect the image when the disconnection occurs is arranged, and the print head control signal 507 is arranged inside.

  The disconnection detection signals 508 and 509 are connected to the ground potential in the carriage substrate 502. The main board 503 is connected to ports 514 and 515 that can record a signal change of the SOC 521 mounted on the board or can notify the CPU, and is connected to a power source via the resistance elements 512 and 513.

  The values of the resistance elements 512 and 513 at this time need to be adjusted in advance so that a voltage that can be detected with respect to a value at which the resistance value starts to change due to the deterioration of the flexible flat cable 504 is obtained.

  Next, examples of disconnection detection in the first embodiment will be described.

  FIG. 6 is a schematic diagram of the printer. In the present embodiment, it is necessary to detect that the flexible flat cable 504 generated only when the print head is at a specific location in the main scanning and backward scanning movements of the print head 501 and the resistance value increase. . Therefore, detection is performed while the print head is moving in the main scanning direction from the position of the head cleaning unit 603 or while moving from the position of the main substrate 503 in the backward scanning direction. For this reason, since detection must be performed while moving at high speed, it is necessary to connect the disconnection detection signals 508 and 509 to the ports 514 and 515 capable of recording the signal change described above or notifying the CPU. .

  The signals detected in the above procedure are as follows when the carriage substrate 502 and the main substrate 503 for controlling the print head are normally fixed by the connectors 505 and 506 with the flexible flat cable 504. Since the other ends of the disconnection detection signals 508 and 509 are connected to the ground potential in the carriage substrate 502, a port capable of recording a signal change to which the other ends of the disconnection detection signals 508 and 509 are connected or notifying the CPU. 514 and 515 are pulled to the ground potential and become L level.

  On the other hand, when the flexible flat cable 504 is disconnected or has a high resistance value, the impedance of the conductors of the disconnection detection signals 508 and 509 is increased, and a resistance partial pressure is generated by the resistance elements 512 and 513. For this reason, the ports 514 and 515 that can record the signal change to which the other ends of the disconnection detection signals 508 and 509 are connected or can notify the CPU are at the H level depending on the impedance of the flexible flat cable 504.

  Accordingly, the states of the ports 514 and 515 that can record a signal change or can be notified to the CPU are changed while the print head is moving from the position of the head cleaning unit 603 in the main scanning direction or from the position of the main substrate 503 in the backward scanning direction. Monitor while moving. By doing so, it is possible to detect that the flexible flat cable 504 is disconnected and has a high resistance value only at a specific portion where the print head occurs before the complete disconnection starts.

  As described above, according to the first embodiment, the disconnection detection signals 508 and 509 are arranged at both outer edges of the flexible flat cable 504, connected to the ground potential by the carriage substrate 502, and mounted on the substrate in the main substrate 503. It is connected to the ports 514 and 515 that can record the signal change of the SOC 521 that can be recorded or notified to the CPU, and is connected to the power source via the resistance elements 512 and 513. A port 514 that can record a signal change or notify the CPU while the print head is moving in the main scanning direction from the position of the head cleaning unit 603 or in the backward scanning direction from the position of the main substrate 503. , 515 is determined. By doing so, it is possible to detect that the flexible flat cable 504 is disconnected and has a high resistance value only at a specific portion where the print head occurs before the complete disconnection starts.

  The overall configuration of the second embodiment will be described. FIG. 7 is a diagram showing an overall configuration of a flexible flat cable connection abnormality detection mechanism provided in the ink jet recording apparatus according to Embodiment 2 of the present invention. As shown in FIG. 7, in the ink jet recording apparatus according to the second embodiment, a carriage substrate 502 that connects the ink jet head 501 and a main substrate 503 that controls the print head are fixed by connectors 505 and 506 with a flexible flat cable 504. The configuration is separable. The inkjet head 501 and the carriage substrate 502 are connected by a pin contact connector 520 and can be separated.

  In the flexible flat cable 504, disconnection detection signals 508 and 509 are arranged along both outer edges. Further, the control signal of the EEPROM 518 and the AD signal of the thermistor for temperature observation are arranged inside, the signal line that does not affect the image when the disconnection occurs is arranged, and the print head control signal 507 is arranged inside.

  The disconnection detection signals 508 and 509 are connected to the ground potential in the carriage substrate 502. The main board 503 is connected to the AD ports 702 and 703 of the SOC 521 mounted on the board, and supplies power via the constant current circuit 701.

  The current value of the constant current circuit 701 at this time needs to be adjusted in advance so that a voltage that can be detected with respect to a value at which the resistance value starts to change due to the deterioration of the flexible flat cable 504 is obtained.

  Next, various examples of disconnection detection in the second embodiment will be described.

  FIG. 6 is a schematic diagram of the printer. In the present embodiment, it is necessary to detect that the flexible flat cable 504 generated only when the print head is at a specific location in the main scanning and backward scanning movements of the print head 501 and the resistance value increase. . Therefore, detection is performed while the print head is moving in the main scanning direction from the position of the head cleaning unit 603 or while moving from the position of the main substrate 503 in the backward scanning direction. By connecting to the AD port 702 described above, the detection speed is inferior to that of the first embodiment, but the resistance value of the flexible flat cable can be detected. Therefore, it is possible to predict the life by recording the resistance value change.

  The signals detected in the above procedure are as follows when the carriage substrate 502 and the main substrate 503 for controlling the print head are normally fixed by the connectors 505 and 506 with the flexible flat cable 504. Since the other ends of the disconnection detection signals 508 and 509 are connected to the ground potential in the carriage substrate 502, the AD ports 702 and 703 to which the other ends of the disconnection detection signals 508 and 509 are connected are drawn to the ground potential and 0V. become.

  On the other hand, when the flexible flat cable 504 is disconnected or has a high resistance value, the impedance of the conductors of the disconnection detection signals 508 and 509 is increased, and a voltage is generated by the current from the constant current circuit 701. Therefore, the AD ports 702 and 703 to which the other ends of the disconnection detection signals 508 and 509 are connected can determine the resistance value based on the voltage level based on the impedance of the flexible flat cable 504.

  Accordingly, the state of the AD ports 702 and 703 is monitored while the print head is moving in the main scanning direction from the position of the head cleaning unit 603 or while moving from the position of the main substrate 503 in the backward scanning direction. By doing so, it is possible to detect that the flexible flat cable 504 is disconnected and has a high resistance value only at a specific portion where the print head occurs before the complete disconnection starts.

  As described above, according to the second embodiment, the disconnection detection signals 508 and 509 are arranged at both outer edges of the flexible flat cable 504, connected to the ground potential by the carriage substrate 502, and mounted on the substrate in the main substrate 503. Are connected to the AD ports 702 and 703 of the SOC 521, and also to the constant current circuit 701. Then, the state of the AD ports 702 and 703 is determined while the print head is moving in the main scanning direction from the position of the head cleaning unit 603 or while moving from the position of the main substrate 503 in the backward scanning direction. By doing so, it is possible to detect that the flexible flat cable 504 has a high disconnection and a high resistance value only when the print head that occurs before the complete disconnection starts is at a specific location.

1 is a schematic perspective view showing a configuration of an embodiment of a color inkjet recording apparatus to which the present invention can be applied. FIG. 3 is an electrical configuration diagram of a recording head to which the present invention can be applied. It is a control block diagram of an ink jet recording apparatus to which the present invention can be applied. The figure which shows the structural example which performs abnormality detection with the conventional connection cable. It is a figure which shows the whole structure of the connection abnormality detection mechanism of Embodiment 1. FIG. 1 is a diagram illustrating a configuration of an ink jet recording apparatus according to Embodiment 1. FIG. It is a figure which shows the whole structure of the connection abnormality detection mechanism of Embodiment 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 103 Paper feed roller 104 Auxiliary roller 105 Paper feed roller 106 Carriage 107 Print paper 108 Recording head 109 Ink cartridge 201 Block data shift register 202 Block data latch 203 Block data decoder 204,209,210,211,212 Driver circuit for each block 205 Heating element 206 Data latch 207 Data shift register 208 Logical product 312 Print head control circuit 314 Discharge detection control circuit 315 CPU
316 Main scanning motor 317 Sub scanning motor 318 Recovery operation motor 319 Recovery operation actuators 320 Recovery operation sensors 321 Mechanism control circuit 322 ROM
323 RAM
324 EEPROM
325 Operation / Display Unit 326 Interface (I / F)
H Host device 401 Connection cable 402 Circuit board 403 Connection conductor 404, 405 Dummy conductor 406, 407 Comparator 501 Print head 502 Carriage board 503 Main board 504 Flexible flat cable 505, 506 Flexible flat cable connection connector 507 Print head control signal 508, 509 Disconnection detection signal 510, 511 Ground potential (GND)
512, 513 Resistive element 514, 515 Port capable of recording signal change or reporting to CPU 516 I2C port 517 AD port 518 E2PROM
519 Thermistor 520 Connector for connecting print head and carriage board 521 SOC and ASIC
601 Flexible flat cable guide 602 Carriage unit shaft 603 Head cleaning unit 701 Constant current power supply circuit 702, 703 AD port

Claims (1)

An inkjet head having a plurality of ink droplet ejection sections for ejecting ink droplets;
A carriage substrate on which a connector connected to the inkjet head is mounted;
A main board for controlling the ink ejection unit and the entire printer;
In an inkjet recording apparatus comprising a flexible flat cable, wherein a plurality of conductors arranged in parallel on a plane in a one-to-one relationship between the carriage substrate and the main substrate are connected by a connector.
At least one arranged at both ends of the flexible flat cable is used as a disconnection detection signal, the disconnection detection signal is connected to a power source via a constant current power source or a pull-up resistor, and the disconnection detection signal is an analog port or a signal. Means for detecting a change in the state of the previous disconnection detection signal while the print head is moving in the main scanning or backward scanning direction, connected to a port capable of recording or notifying the CPU of the state change;
An ink jet recording apparatus comprising:

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