JP2010137362A - Liquid jetting type printing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jetting type printing apparatus which can control and prevent vibration of the apparatus itself. <P>SOLUTION: An action force particularly at the time of acceleration and deceleration is offset by moving a carriage for image reading 4 at an equivalent speed in a reverse direction to those of a carriage 14 for printing with respect to the movement of the carriage 14 for printing at the time of printing to a printing medium 1, so that the vibration of the apparatus can be controlled and prevented. Also, an image reading optical head 5 is mounted on the carriage 4 for image reading as a balancing movable body, whereby the function of an image reader is added to the liquid jetting type printing apparatus. An efficient combination type printing apparatus can be obtained accordingly. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid jet printing apparatus that prints predetermined characters or images by ejecting minute liquid from a plurality of nozzles and forming fine particles (dots) on a print medium. It is.

In general, liquid jet printing apparatuses are widely used not only in offices but also in general users with the spread of personal computers and digital cameras, because inexpensive and high-quality color prints can be easily obtained.
Among such liquid ejecting printing apparatuses, those that place a liquid ejecting head in which liquid ejecting nozzles are formed on a moving body called a carriage and move in a direction crossing the transport direction of the print medium are generally referred to as “multi-pass printing”. Called "device". On the other hand, what is capable of printing in a so-called one pass by arranging a long liquid jet head in a direction crossing the conveyance direction of the printing medium is generally called a “line head type printing apparatus”.

In this type of liquid ejecting printing apparatus, a plurality of nozzles for ejecting liquid are formed on a liquid ejecting head, and nozzle actuators such as piezoelectric elements are provided for each nozzle, and a drive signal is sent to each nozzle actuator. By applying, the liquid is ejected from the corresponding nozzle toward the print medium. In the following Patent Document 1, in a multi-pass type printing apparatus, a composite printing in which an image reading optical head is mounted on one carriage together with a liquid jet head for jetting liquid, and the image reading apparatus and the liquid jet printing apparatus are combined. A device is proposed.
JP-A-6-336018

By the way, in the above-described multi-pass printing apparatus, printing is performed by ejecting liquid from the liquid ejecting head while reciprocating the carriage on which the liquid ejecting head is mounted, for example, in a direction intersecting the transport direction of the print medium. In order to increase the printing speed, that is, to shorten the time required for printing in such a multi-pass type printing apparatus in which the size of the liquid ejecting head is limited, the moving speed of the carriage equipped with the liquid ejecting head must be increased. I must. In order to reciprocate the carriage, there are acceleration and deceleration processes at the beginning and end of one movement process, respectively, and increasing the speed of movement of the carriage increases the acting force during acceleration / deceleration. When the acting force at the time of acceleration / deceleration of the carriage increases, the carriage on which the liquid ejecting head is mounted is a mass body, and thus a force that vibrates the printing apparatus itself is applied. As a result, for example, when a multi-pass type liquid jet printing apparatus is placed on a table called a PC rack and printing is performed, there arises a problem that the table vibrates.
The present invention has been developed paying attention to these problems, and an object of the present invention is to provide a liquid jet printing apparatus capable of suppressing and preventing vibration of the apparatus itself.

  In order to solve the above problems, a liquid ejection printing apparatus according to the present invention includes a liquid ejection head that ejects liquid and ejects liquid from the liquid ejection head while reciprocating in a predetermined direction with respect to a print medium. A printing moving body that performs printing, a balancing moving body that can reciprocate in the opposite direction to the printing moving body, and performing printing while reciprocating the printing moving body, and the balancing moving body. And a control means for reciprocating in the opposite direction at the same speed as that of the printing moving body.

According to this liquid jet printing apparatus, the acting force during acceleration / deceleration when moving the printing moving body at a high speed by moving the balancing moving body back and forth at the same speed and in the opposite direction as the printing moving body. Can be offset by that of the balance moving body, and thus the vibration of the apparatus itself can be suppressed and prevented.
The liquid jet printing apparatus of the present invention is characterized in that an image reading optical head is mounted on the balance moving body.
According to this liquid jet printing apparatus, an efficient composite printing apparatus can be obtained by adding the function of an image reading device to the liquid jet printing apparatus.

Next, an embodiment of a liquid jet printing apparatus according to the present invention will be described with reference to the drawings.
FIG. 1 is an overall view including the printing apparatus according to the present embodiment. A monitor 100, a keyboard 102, a mouse 103, and a personal computer main body 104 are placed on a stand 100 called a PC rack. The liquid jet printing apparatus 3 of the present embodiment is placed. Note that reference numeral 1 in the drawing denotes a printing medium, which is conveyed from the back of the liquid jet printing apparatus 3 to the front side. The conveyance direction of the print medium 1 is also referred to as a sub-scanning direction.

  FIG. 2 shows details of the liquid jet printing apparatus 3 of FIG. 2a shows the device with the top cover removed, and FIG. 2b shows the device with the front part removed. Reference numeral 4 in FIG. 2 a provided in front of the apparatus, that is, on the front side of FIG. 1 is an image reading carriage as a balance moving body, and linearly reciprocates along the guide 6 in the horizontal direction in the figure. Mounted movably. An image reading conveyance belt 10 is attached to the image reading carriage 4, and the image reading conveyance belt 10 is wound around an image reading driving pulley 8 and an image reading driven pulley 9 to drive the image reading. An image reading carriage motor 7 is connected to the pulley 8. Accordingly, when the image reading carriage motor 7 is rotated in the forward and reverse directions, the image reading conveying belt 10 is reciprocated in the horizontal direction in the figure, and accordingly, the image reading carriage 4 is moved in the horizontal direction in the figure, that is, It is reciprocated in the direction crossing the sub-scanning direction. This carriage movement direction is also referred to as the main scanning direction. The image reading carriage motor 7 is composed of a pulse motor that rotates by a predetermined angle for each pulse signal.

  An image reading optical head 5 is mounted on the image reading carriage 4. The image reading optical head 5 has a function equivalent to that of an existing scanner. For example, the image reading optical head 5 irradiates light on the image on the print medium 1 and reads the shape and color of the image from the reflected state. Then, the control device 13 functioning as a control unit that reciprocates the balance moving body at the same speed and in the opposite direction as the printing moving body, which will be described later, controls the rotation state of the image reading carriage motor 7. The reading carriage 4 is reciprocated in the main scanning direction by accelerating / constant speed / deceleration / reversing / acceleration / constant speed / deceleration / reversing, and the image reading optics 4 is moving when the image reading carriage 4 is moving at a constant speed. The head 5 reads an image on the print medium 1. The content read by the image reading optical head 5 is transmitted to the control device 13 via the flexible flat cable 11. The print medium 1 is conveyed from the back of the figure to the near side, that is, in the sub-scanning direction by a paper feed roller (not shown) at the back of the figure, and a pair of upper and lower discharge rollers (not shown). To the outside of the device. At that time, the print medium 1 is printed by ink ejected from the nozzles of the liquid ejecting head 2 facing on the platen roller 12 functioning as guide positioning.

  Reference numeral 14 in FIG. 2b provided at the back of the apparatus, that is, at the back side in FIG. 1 is a printing carriage as a printing moving body, and linearly reciprocates along the guide 16 in the horizontal direction in the figure. Installed as possible. A printing conveyance belt 20 is attached to the printing carriage 14, and the printing conveyance belt 20 is wound around a printing driving pulley 18 and a printing driven pulley 19. A carriage motor 17 is connected. Accordingly, when the printing carriage motor 17 is rotated in the forward and reverse directions, the printing conveyance belt 20 is reciprocated in the horizontal direction in the drawing, that is, the main scanning direction described above, and the printing carriage 14 is moved accordingly. It is reciprocated in the horizontal direction, that is, the main scanning direction. Accordingly, the printing carriage 14 and the image reading carriage 4 are reciprocated in parallel with each other. The printing carriage motor 17 is also configured by a pulse motor that rotates by a predetermined angle for each pulse signal.

  A cartridge 22 that stores a liquid such as ink is mounted on the upper portion of the printing carriage 14, and a liquid ejecting head that ejects a liquid such as ink supplied from the cartridge 22 is disposed on the lower portion of the printing carriage 14. 2 is installed. A large number of nozzles (not shown) are formed on the lower surface of the liquid jet head 2 in the figure, and liquid is ejected from the nozzles to perform printing on the print medium 1. The cartridge 22 stores, for example, liquids such as yellow (Y), magenta (M), cyan (C), and black (K) inks. Then, by ejecting a necessary amount of liquid from a nozzle formed in the liquid ejecting head 2 to a necessary location, it is possible to form minute dots on the print medium 1. By performing this for each color while reciprocating the printing carriage 14 in the main scanning direction and transporting the printing medium 1 in the sub-scanning direction, printing can be performed on the entire printing surface of the printing medium 1.

  Each nozzle is provided with a nozzle actuator such as a piezoelectric element, and a liquid is ejected from each nozzle by applying a drive signal described later to the nozzle actuator. As a method of ejecting liquid from each nozzle of the liquid ejecting head, there are an electrostatic method, a piezo method, a film boiling liquid ejecting method, and the like. In this embodiment, the piezo method is used. In the piezo method, when a drive signal is given to a piezoelectric element that is a nozzle actuator, the diaphragm that forms the wall of the cavity (pressure chamber) is displaced, causing a pressure change in the cavity, and the pressure change causes the droplet to open to the nozzle. It is ejected from the part. The droplet ejection amount can be adjusted by adjusting the peak value of the drive signal and the voltage increase / decrease slope. Note that the present invention can be similarly applied to liquid ejection methods other than the piezo method. Further, the liquid ejecting head 2, more specifically, the nozzle actuator in the liquid ejecting head 2, is connected to the control device 13 via the flexible flat cable 21.

  A paper feed roller (not shown) that transports the print medium 1 in the sub-scanning direction is driven by a paper feed roller motor 23. The paper feed roller motor 23 is also composed of a pulse motor that rotates by a predetermined angle for each pulse signal. By controlling the rotation state of the paper feed roller motor 23 with the control device 13, the print medium 1 can be conveyed by a predetermined amount in the sub-scanning direction. Further, the control device 13 controls the rotation state of the printing carriage motor 17 so that the printing carriage 14 is reciprocated in the main scanning direction by accelerating, constant speed, decelerating, reversing, accelerating, constant speed, decelerating, and reversing. By moving and controlling the nozzle actuator of the liquid ejecting head 2, the liquid is ejected onto the print medium 1 when the printing carriage 14 is moving at a constant speed. That is, acceleration / deceleration / reversal of the printing carriage 14 is performed in a so-called non-printing area that is out of the printing medium 1.

  In a non-printing region where the printing carriage 14 is movable, a cleaning device 24 for cleaning the liquid ejecting head 2 and a capping device 25 for sealing the liquid ejecting head 2 during non-printing to prevent drying of the nozzle opening are provided. It has been. The cleaning device 24 is in close contact with the nozzle surface of the liquid jet head 2 and slides the nozzle surface to remove dust, paper dust, or residual ink droplets attached to the vicinity of the nozzle. Further, the capping device 25 drives the pump unit 26 by the paper feed roller motor 23, and sucks the liquid from the nozzle by sucking the space between the capping device 25 and the nozzle surface by the pump unit 26. Further, the capping device 25 also functions as a flushing liquid receiver that ejects liquid from the nozzles of the liquid ejecting head 2 in a non-printing state, for example, to discharge thickened liquid.

  FIG. 3 shows a schematic configuration of the control device 13. The control device 13 performs printing processing on a printing medium by controlling a printing device, a paper feeding device, or the like based on print data input from a host computer 60 such as a personal computer or a digital camera, or reads an image. Or something to do. For example, a control constituted by an input interface 61 for reading print data input from the host computer 60 and, for example, a microcomputer that executes arithmetic processing such as print processing based on the print data input from the input interface 61. A sheet feeding roller motor driver 63 that drives and controls the sheet feeding roller motor 23 connected to the sheet feeding roller (not shown), and a printing carriage motor driver that drives and controls the printing carriage motor 17. 64, a head driver 65 for driving and controlling the liquid ejecting head 2, an image reading carriage motor driver 66 for driving and controlling the image reading carriage motor 7, the drivers 63 to 66, the paper feed roller motor 23, and printing. Carriage motor 17, liquid ejecting head 2, Configured with an interface 67 for connecting the image reading carriage motor 7.

  The control unit 62 temporarily stores a CPU (Central Processing Unit) 62a that executes various processes such as a print process, and print data input through the input interface 61 or various data when the print data print process is executed. A random access memory (RAM) 62c that temporarily stores a program such as a print process or a nonvolatile semiconductor memory that stores a control program executed by the CPU 62a. ) 62d. For example, with regard to overall print control, when the control unit 62 obtains print data (image data) from the host computer 60 via the input interface 61, the CPU 62a executes predetermined processing on the print data, and Nozzle selection data (driving signal selection data) indicating from which nozzle of the liquid ejecting head 2 or how much liquid is to be ejected is calculated, and this print data, driving signal selection data, and various sensors are used. Based on the input data, a control signal is output to each of the drivers 63-66. A drive signal is output from each of the drivers 63 to 66, and the paper feed roller motor 23, the printing carriage motor 17, the image reading carriage motor 7, the nozzle actuator in the liquid ejecting head 2, and the like are operated, respectively. Paper feed, conveyance, paper discharge, and print processing on the print medium 1 are executed. Each component in the control unit 62 is electrically connected through a bus (not shown).

  FIG. 4 shows an example of a drive signal COM that is supplied from the control device 13 of the printing apparatus of the present embodiment to the liquid ejecting head 2 and drives a nozzle actuator made of a piezoelectric element. In the present embodiment, a signal whose potential changes around an intermediate potential is used. This drive signal COM is a time series connection of drive pulses PCOM as unit drive signals for driving the nozzle actuator to eject liquid, and the rising portion of each drive pulse PCOM communicates with the nozzle (pressure). The volume of the chamber is expanded and the liquid is drawn in (it can be said that the meniscus is drawn in considering the liquid ejection surface), and the falling portion of the drive pulse PCOM reduces the cavity volume and pushes out the liquid (liquid In this stage, it can be said that the meniscus is extruded), and as a result of extruding the liquid, droplets are ejected from the nozzle.

  By variously changing the voltage increase / decrease slope and peak value of the driving pulse PCOM composed of this voltage trapezoidal wave, the liquid drawing amount and drawing speed, the liquid pushing amount and the pushing speed can be changed. It is possible to obtain dots of different sizes by changing the amount of injection. Therefore, even when a plurality of drive pulses PCOM are connected in time series, a single drive pulse PCOM is selected and supplied to the actuator, and droplets are ejected or a plurality of drive pulses PCOM are selected and the actuator is selected. In this way, dots of various sizes can be obtained by ejecting droplets a plurality of times. That is, if a plurality of droplets land on the same position before the liquid dries, it is substantially the same as ejecting a large droplet, and the size of the dot can be increased. By combining such techniques, it is possible to increase the number of gradations. Note that the driving pulse PCOM1 at the left end in FIG. This is called microvibration, and is used, for example, to suppress or prevent thickening of ink at the nozzle portion without ejecting droplets.

  In addition to the drive signal COM, each liquid ejecting head 2 selects a nozzle to be ejected based on print data as a control signal from the control device 13 in FIG. 3 and also to a drive signal COM for a nozzle actuator such as a piezoelectric element. Drive signal selection data SI & SP for determining the connection timing of the signal, serially latch signal LAT and channel signal CH for connecting the drive signal COM and the nozzle actuator of the liquid ejecting head 2 based on the drive signal selection data SI & SP, and drive signal selection data SI & SP A clock signal CLK for transmitting to the liquid jet head 2 as a signal is input.

FIG. 5 shows a flowchart of generic calculation processing for print control. In this calculation process, first, in step S1, the drive signal selection data SI & SP is read.
Next, the process proceeds to step S2, and the relationship between the positions of the printing carriage 14 and the print medium 1 and the selected drive signal COM (drive pulse PCOM) is stored.
Next, the process proceeds to step S3, and the movement control and printing control of the printing carriage 14 are performed as described above in accordance with individual arithmetic processing (not shown). The movement control is to control the position and speed of the printing carriage 14 as described above, and the printing control is to select the drive signal COM (drive pulse PCOM) in relation to the position of the printing carriage 14. In other words, the liquid is ejected to a predetermined position of the print medium 1. Note that the print control is also performed in association with the conveyance state of the print medium 1 in the subsequent step S6.

In step S4, the image reading carriage 4 is controlled to move at a constant speed and in the opposite direction to the printing carriage 14 according to an individual calculation process (not shown). Specifically, the speed control of the movement control of the printing carriage 14 in step S3 is read, and the rotation state of the image reading carriage motor 7 is controlled so that the image reading carriage 4 moves in the reverse direction at the same speed. To do.
Next, the process proceeds to step S5, the movement control of the print medium 1 is performed according to an individual calculation process (not shown), and then the process returns to the main program. Specifically, every time the printing carriage 14 completes moving the print medium 1 in the main scanning direction, the paper feed roller motor 23 is rotated by a predetermined rotation, and the print medium 1 is conveyed by a predetermined amount.

According to this arithmetic processing, when printing on the print medium 1, the image reading carriage 4 moves in the opposite direction to the movement of the printing carriage 14 at the same speed and in the opposite direction. The acting force during deceleration cancels out, and the vibration of the apparatus can be suppressed and prevented. In addition, since the image reading optical head 5 is mounted on the image reading carriage 4 which is a balance moving body, the function of the image reading device is added to the liquid jet type printing device, and an efficient composite type printing device is obtained. Obtainable.
In the above embodiment, at the time of printing, the image reading carriage 4 is simply moved at the same speed as the printing carriage 14 and in the reverse direction. However, for example, the reading speed of the image reading optical head 5 is high. Then, the printing state of the liquid ejected from the liquid ejecting head 2 of the printing carriage 14 is read by the image reading optical head 5 of the image reading carriage 4 that is moved in the reverse direction at the same speed as the printing carriage 14. It is also possible to feed back the read contents to the print control.

  In the above-described embodiment, the liquid jet printing apparatus of the present invention is embodied as one that ejects liquid such as ink. However, the present invention is not limited to this, and other liquids other than ink (in addition to liquids, functional materials It may be embodied in a liquid ejecting apparatus that ejects or discharges a fluid other than a liquid (including a liquid material in which particles are dispersed, a fluid such as a gel), or a fluid other than a liquid (such as a solid that can be ejected as a fluid). it can. For example, a liquid material ejecting apparatus that ejects a liquid material that contains materials such as electrode materials and color materials used in the manufacture of liquid crystal displays, EL (electroluminescence) displays, surface-emitting displays, color filters, and the like in a dispersed or dissolved form. Further, it may be a liquid ejecting apparatus that ejects a bio-organic matter used for biochip manufacturing, or a liquid ejecting apparatus that ejects a liquid that is used as a precision pipette to become a sample. In addition, transparent resin liquids such as UV curable resins for forming liquid injection devices that inject lubricating oil onto precision machines such as watches and cameras, micro hemispherical lenses (optical lenses) used in optical communication elements, etc. Examples include a liquid ejecting apparatus that ejects a liquid onto a substrate, a liquid ejecting apparatus that ejects an etching solution such as acid or alkali to etch the substrate, a fluid ejecting apparatus that ejects a gel, and a powder such as toner. It may be a fluid ejection recording apparatus that ejects a solid. The present invention can be applied to any one of these injection devices.

1 is an overall configuration diagram illustrating an embodiment of a liquid jet printing apparatus according to the present invention. FIG. 2 is a detailed explanatory diagram of the liquid jet printing apparatus of FIG. 1. FIG. 2 is a block diagram of a control device of the liquid jet printing apparatus of FIG. 1. FIG. 3 is an explanatory diagram of a drive signal that drives a nozzle actuator in the liquid jet head of FIG. 2. 4 is a flowchart of print control performed by a control unit in FIG. 3.

Explanation of symbols

  1 is a print medium, 2 is a liquid ejecting head, 3 is a liquid ejecting printing apparatus, 4 is an image reading carriage (balance moving body), 5 is an image reading optical head, 6 is a guide, and 7 is an image reading carriage motor. 8 is an image reading drive pulley, 9 is an image reading driven pulley, 10 is an image reading conveying belt, 11 is a flexible flat cable, 12 is a platen roller, 13 is a control device, and 14 is a printing carriage (moving for printing). Body), 16 is a guide, 17 is a printing carriage motor, 18 is a driving pulley for printing, 19 is a driven pulley for printing, 20 is a conveying belt for printing, 21 is a flexible flat cable, 22 is a cartridge, and 23 is a feeding roller. Motor, 24 cleaning device, 25 capping device

Claims (2)

  A printing moving body that includes a liquid ejecting head that ejects liquid and reciprocates in a predetermined direction with respect to a print medium to eject the liquid from the liquid ejecting head, and is opposite to the printing moving body The balance moving body capable of reciprocating in the direction and the printing moving body are reciprocated to perform printing, and the balancing moving body is reciprocated in the opposite direction at the same speed as the printing moving body. And a liquid ejecting type printing apparatus.   The liquid jet printing apparatus according to claim 1, wherein an image reading optical head is mounted on the balance moving body.

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