JP2010069745A - Inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recorder which prevents troubles occurring due to the penetration of liquid and dust into a print head in such a severe service environment that requires waterproof and dustproof performance and can maintain the normal condition of the recorder without requiring a special maintenance. <P>SOLUTION: A charge control type inkjet recorder to form characters on a printing object with ink particles jetted from a print head includes: an electrification electrode for applying an electrification voltage used as an alphabetic signal to the ink particles jetted from a nozzle; a deflection electrode for imparting electric charges to the ink particles to which the electrification voltages have been applied by the electrification electrode to deflect the flying direction; and a print head cover covering the nozzle, the electrification electrode, and the deflection electrode. The print head cover has an opening for passing the ink particles jetted from the nozzle and a shielding mechanism for shielding the opening. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to the structure of a print head of a charge control type ink jet recording apparatus.

  Inkjet recording apparatuses are currently widely used for printing characters such as production lot numbers, production dates, and expiration dates on products of all industries. Due to the wide variety of industries, the environment used is also varied. Among them, it is installed in the production line of food and beverage, and the environment where liquid for washing the production line is applied, wood processing, plastic pipe processing There are also harsh environments for inkjet recording devices, such as environments with very high dust levels such as lines. For this reason, recent inkjet recording apparatuses are generally waterproof and dustproof.

  In such a situation, the problem with securing waterproof and dustproof performance is the opening of the print head. In an ink jet recording apparatus, in principle, it is necessary to eject ink particles out of the print head, and this opening is indispensable. Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 2006-341529 (Patent Document 1), the opening is made as small and small as possible to reduce the entry of water and dust as much as possible. However, as the dust-proofing and waterproofing performance of the ink jet recording apparatus main body increases, the environment in which it is used is becoming harsher, so this opening cannot be ignored.

  The problem that occurs in such a harsh environment is when the liquid for cleaning the customer's production line penetrates into the print head from this opening and adheres to the nozzle or electrode section, so that normal ink cannot be ejected. In addition, when a voltage is applied to the electrodes, the electrodes may be short-circuited through the attached liquid, and the apparatus may not operate normally.

  In addition, in a dusty environment, when ink is not ejected, dust may enter the nozzle and the nozzle becomes clogged, making it impossible to eject ink normally, or a gutter that collects ink particles that are not used for printing. Ink may not be collected due to the intrusion of dust from the part, or foreign matter may be mixed into the ink circulation path to adversely affect the operation of the entire apparatus.

JP 2006-341529 A

  With conventional inkjet recording devices, printing is required when the product is used in a production line for food, beverages, etc., where the liquid is splashed when the line is washed, or in a dusty environment such as a wood processing or plastic pipe processing line. When liquid or dust enters the head, the apparatus may not be able to print normally. In order to avoid such a situation, it is necessary to clean the inside of the print head and the nozzles manually every time the line is operated, resulting in an increase in setup time and a decrease in production efficiency. is there.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording apparatus that prevents liquid and dust from entering a print head even in a severe use environment where high waterproof and dustproof performance is required.

  In order to solve the above-described problems, the present invention provides, for example, a nozzle that pressurizes and ejects ink supplied from a main body, a charging electrode that applies a charging voltage that becomes a character signal to ink particles ejected from the nozzle, and Ejected from the print head provided with a deflection electrode for applying a charge to the ink particles to which a charging voltage is applied by the charging electrode and deflecting the flight direction, and a print head cover covering the nozzle, the charging electrode and the deflection electrode. In the charge control type ink jet recording apparatus that forms characters on the print object with the ink particles thus formed, the print head cover has an opening for allowing the ink particles ejected from the nozzle to pass therethrough, and A configuration is adopted in which a shielding mechanism for shielding the opening is provided.

  According to the present invention, even in a severe use environment where high waterproof and dustproof performance is required, the maintenance of the print head caused by the environment becomes unnecessary, and the downtime of the production line can be minimized. An ink jet recording apparatus can be provided.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the overall configuration of an ink jet recording apparatus according to the present invention. The ink jet recording apparatus is roughly composed of a main body 101 and a print head 102. A print head cover 103 is attached to the print head 102, and maintenance of the print head is performed by removing the print head cover 103. During normal use, the print head cover 103 remains attached, and during printing, ink particles pass through the opening 104 provided on the print head cover 103 and reach the print object 115 so that characters are printed. Is printed.

  FIG. 2 is a diagram showing the configuration of the print head in the present invention. Inside the print head are nozzles 105 for ejecting ink particles, charging electrodes 106 for applying a charging voltage as character signals to the ink particles, deflection electrodes 107 for deflecting charged ink particles by an electric field, printing It comprises a gutter 108 for collecting ink particles that are not used in the process.

  Ink particles used for printing are ejected out of the print head 102 through an opening 104 provided in the print head cover 103. The conventional problem is that liquid or dust enters the inside of the print head from the opening 104 and clogs the nozzle 105, adheres to the charging electrode 106 and the deflection electrode 107, causes a short circuit between the electrodes, or the gutter 108. In other words, foreign matter may enter the ink circulation path.

  Therefore, as a means for solving this problem, a structure having a shutter mechanism for closing the opening 104 in the print head unit has been invented. As a shutter mechanism for closing the opening 104, for example, a structure in which the user can arbitrarily close the opening using a cap-shaped component 110 having a convex protrusion as shown in FIG. 2 is conceivable. In addition, a structure in which a sliding plate 109 is provided at the tip of the gutter 108 so as to be in close contact with the print head cover 103 as shown in FIG. If this slide-type plate can be manually opened and closed, the user closes the slide-type plate after the operation of the ink jet recording apparatus is finished and reopens it at the start of the operation, so that the print head can be used when the ink jet recording apparatus is not in operation. It is possible to achieve internal waterproofing and dustproofing.

  In the case of the manual type, a warning message indicating that the cap 110 or the shutter 109 is to be closed is displayed on the display device 120 after completion of the ink stop process, so that it is possible to prevent forgetting to attach the cap and forgetting to close the shutter. is there. On the contrary, when the ink ejection process is selected, by displaying a message confirming that the cap 110 or the shutter 109 is open, it is possible to prevent forgetting to remove the cap 110 or forgetting to open the shutter 109.

  As a point to consider when providing these mechanisms, since there is a deflection electrode to which a high voltage is applied inside the head, it is necessary to ensure a sufficient distance from the electrode. In selecting a material, it is necessary to select a material such as plastic, rubber, or metal having solvent resistance.

  As another embodiment, it is possible to use a mechanism that can be electrically opened and closed such as an electromagnetic shutter for the shutter mechanism 109 shown in FIG. As a result, the opening / closing operation can be automated, the opening / closing operation can be optimized in accordance with the operating state of the apparatus, and the effect of waterproofing and dustproofing can be enhanced as compared with the manual type. In addition, it is possible to prevent the occurrence of a secondary problem due to the user forgetting to perform the opening / closing operation.

  FIG. 4 is a block diagram showing the configuration of this embodiment. First, an outline of the configuration of the control unit will be described. 116 is an MPU (microprocessing unit) that controls the entire inkjet recording apparatus, 122 is a ROM (read only memory) that stores a control program and data necessary for the MPU to operate, and 123 is necessary during execution of the program Is a RAM (rewritable memory) that temporarily stores data. A storage device 124 stores programs, print data, and the like.

  Reference numeral 119 denotes an input panel for inputting print contents and set values, 120 denotes a display device for displaying input data and print contents, and 125 denotes a bus line for transmitting MPU data signals, address signals, and control signals. Reference numeral 118 denotes an excitation voltage generation circuit for generating a voltage for forming ink particles, and reference numeral 117 denotes a charging voltage generation circuit for generating a voltage corresponding to a character signal in the ink particles. Reference numeral 121 denotes a control circuit for electrically operating the shutter mechanism in the present invention.

  Next, an outline of the configuration of the printing and ink circulation unit will be described. The ink ejected from the nozzle 105 is formed into ink particles 112 by the electrostrictive element of the nozzle by the excitation voltage generated by the excitation voltage generation circuit 118. The voltage generated by the charging voltage generation circuit 117 is applied to the charging electrode 106, and the ink particles are charged with a voltage corresponding to the character signal. The charged ink particles 112 fly in the electric field created by the deflection electrode 107, are deflected according to the amount of charge, and reach the printed material 113 that is moved by the conveyor 114 to form characters. Ink particles that are not used for printing are collected by the ink collecting gutter 108 and supplied to the nozzle 109 again by the pump 115.

  As a specific control timing of the opening / closing operation in the configuration shown in FIG. 4, for example, it is conceivable to control by the presence or absence of ink ejection from the nozzle. Since the state of the ink jet recording apparatus is controlled by the MPU 116, by outputting an opening / closing instruction signal to the shutter control circuit 121, when the ink is not ejected from the nozzle, the shutter mechanism is closed and the user sets the ink. When the ejection operation is performed, it is possible to realize control such as automatically opening the shutter. Further, when the user performs the process of stopping ink ejection, the shutter may be closed again.

  As a method for realizing a finer opening / closing operation, a method of controlling depending on whether or not a deflection voltage is applied to the deflection electrode 107 can be considered. Usually, in an ink jet recording apparatus, an input signal from a sensor for detecting an object to be printed is detected, and printing is performed for each signal. In order to detect the signal from the sensor and perform printing instantaneously, the printer stands by with the deflection voltage applied, and only the ink particles to which the charging voltage is applied are deflected and used for printing. Therefore, by performing the control to open the shutter only when a deflection voltage is applied, ink is ejected from the nozzle, such as when warming up or when an abnormality occurs, but if it is not in the print standby state, The shutter can be closed to keep it waterproof and dustproof. Similar to the above-described presence / absence of ink ejection, an opening / closing instruction signal may be output to the shutter control circuit 121 in accordance with the presence / absence of application of a deflection voltage instructed from the MPU 116 to the high-voltage power supply control circuit 126.

  When these electromagnetic shutter mechanisms are used, the shutter mechanism needs to be closed even when the ink jet recording apparatus is not energized. By configuring in this way, even when a power failure occurs in an environment where power conditions are bad, the shutter is immediately closed, so that ink leaks from the nozzle that has become uncontrollable, and the dropped ink drops on the customer's line, It is also possible to minimize the contamination of the printing object.

  As described above, with the above-described configuration, it is possible to realize an ink jet recording apparatus that can prevent liquid and dust from entering the print head.

1 is a perspective view illustrating an appearance of an ink jet recording apparatus according to an embodiment. FIG. 3 is a diagram illustrating an example of an internal configuration of a print head according to the present embodiment. FIG. 3 is a diagram illustrating an example of an internal configuration of a print head according to the present embodiment. It is a block diagram which shows schematic structure of the inkjet recording device concerning a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Main body of inkjet recording apparatus, 102 ... Print head, 103 ... Print head cover, 104 ... Print head cover opening, 105 ... Print nozzle, 106 ... Charging electrode, 107 ... Deflection electrode, 108 ... Gutter, 109 ... Shutter, 110 ... Cap DESCRIPTION OF SYMBOLS 111 ... High voltage power supply, 112 ... Ink particle, 113 ... Print object, 114 ... Conveyor, 115 ... Pump, 116 ... MPU, 117 ... Charge voltage generation circuit, 118 ... Excitation voltage generation circuit, 119 ... Input panel, 120 ... Display device 121 ... Shutter control circuit 122 ... ROM 123 ... RAM 124 ... Storage device 125 ... Bus line 126 ... High voltage power supply control circuit

Claims (6)

A nozzle that pressurizes and ejects the ink supplied from the main body, a charging electrode that applies a charging voltage as a character signal to the ink particles ejected from the nozzle, and an ink particle to which a charging voltage is applied by the charging electrode Characters are formed on an object to be printed by ink particles ejected from the print head provided with a deflection electrode that imparts an electric charge and deflects the flight direction, and a print head cover that covers the nozzle, the charging electrode, and the deflection electrode. In the charge control type inkjet recording apparatus,
The print head cover has an opening for allowing the ink particles ejected from the nozzles to pass therethrough, and is provided with a shielding mechanism for shielding the opening. apparatus.   The inkjet recording apparatus according to claim 1, wherein the shielding mechanism is a member having a convex portion that is inserted into the opening from the outside of the print head cover.   The inkjet recording apparatus according to claim 1, wherein the shielding mechanism is a shutter mechanism that can open and close the opening provided in the print head cover.   4. The ink jet recording apparatus according to claim 1, wherein a member that closes the opening portion of the shielding mechanism has solvent resistance and is plastic or rubber. 5.   The ink jet recording apparatus according to claim 3, wherein the opening and closing of the shutter mechanism is performed in conjunction with the presence or absence of ejection of ink particles from the nozzle.   6. The ink jet recording apparatus according to claim 3, wherein the shutter mechanism is opened and closed in conjunction with the presence or absence of a deflection voltage in the deflection electrode.

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