JPH11165406A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording apparatus capable of always performing good printing by an ink jet printing head even when a printed matter having a three-dimensional structure is used. SOLUTION: In an ink jet recording apparatus equipped with a movable arm having an ink jet printing head 3 provided at its leading end part 13 and a control apparatus for holding the movable arm to move the movable arm, the printing head 3 is equipped with a distance measuring part 18 for measuring the distance between the printing head 3 and a printed matter 5, and an ink jet control part 19 alters the printing state in the printing head 3, concretely, the amplitude of the pulse signal supplied to the emitting electrode of an ink jet head part 16 or the voltage of bias voltage and the amplitude of the pulse signal corresponding to the distance data obtained by the distance measuring part 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly, to a robot type which can move a print head in accordance with the three-dimensional structure even if the printed matter has a three-dimensional structure. The present invention relates to an inkjet recording apparatus.

[0002]

2. Description of the Related Art Conventionally, an ink jet recording apparatus moves a recording sheet in a one-dimensional direction along a recording sheet in a state where an ink jet print head is arranged to face a printed material (usually a recording sheet), and moves the recording sheet to the ink jet print head. By moving in a one-dimensional direction perpendicular to the moving direction of the recording paper, predetermined printing is performed on recording paper. This type of inkjet recording apparatus is, for example,
It is disclosed in JP-A-58-194540.

On the other hand, when painting the surface of a three-dimensionally structured article such as an automobile body, a painting robot is usually used. The coating robot includes a movable arm having a coating gun disposed at a tip thereof, and a control device for holding the movable arm and moving the movable arm to move the coating gun to a coating position on the surface of the workpiece. It adjusts the moving position of the coating gun according to the defined work program, and paints the surface of the painted object.
One example of this type of painting robot is disclosed in
No. 4982 and JP-A-7-195000.

[0004]

In the known ink jet recording apparatus, when printing is performed on a print (recording paper) using an ink jet print head, the distance between the ink jet print head and the print (recording paper) is kept constant. In this state, printing is performed by moving the inkjet print head substantially two-dimensionally with respect to the printed matter (recording paper) in a state where the ink jet print head and the printed matter are constantly printed in order to perform good printing. It is necessary to keep the distance between the inkjet print head and the printed matter (recording paper) constant if the printed matter has a three-dimensional structure or for some reason. In the case where it disappears, there is a problem that good printing cannot be performed.

[0005] The known painting robot can move the painting gun appropriately by using a movable arm.
Although it is possible to perform coating of relatively good quality on a painted object having a three-dimensional structure, when painting a painted object having a three-dimensional structure, the moving position of the painting gun is determined by moving the painted gun having the three-dimensional structure. Since the shape is represented using the coordinates of the representative point of the painted object, when the painting gun is moved, it cannot be completely moved along the shape of the painted object having a three-dimensional structure. There is a problem that it is difficult to always maintain a constant distance between the gun and the coating having a three-dimensional structure.

[0006] From these points, even if the moving means of the coating gun in the known coating robot is simply used as the moving means of the ink jet print head in the known ink jet recording apparatus, the printed matter and the ink jet print head are always used. Therefore, it is impossible to obtain an ink jet recording apparatus capable of performing good printing by the ink jet print head because the distance between the ink jet recording head and the ink jet recording head cannot be kept constant.

The present invention solves these problems, and an object of the present invention is to always perform good printing with an ink jet print head even when using a printed material having a three-dimensional structure. Another object of the present invention is to provide a simple ink jet recording apparatus.

[0008]

In order to achieve the above object, an ink jet recording apparatus according to the present invention comprises a movable arm having an ink jet print head at a front end, a control for holding the movable arm and moving the movable arm. A distance measuring unit for measuring a distance between the print head and the printed matter in the print head, and a controller for changing a printing state of the print head in accordance with the distance information obtained by the distance measuring unit in the control device. Is provided.

According to the above means, when the movable arm is moved to move the ink jet print head to a predetermined print area on the surface of the printed matter, the distance between the print head and the printed matter is measured, and the measurement result is obtained. The print state of the print head is changed in accordance with the print condition, for example, the amount of ink discharged from the print head is changed, so that good quality printing is always performed on the surface of the printed matter.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In an embodiment of the present invention, an ink jet recording apparatus includes a movable arm having an ink jet print head at a leading end, and a control device for holding the movable arm and moving the movable arm. Wherein the print head includes a distance measuring unit that measures an interval between the print head and the printed matter, and the control device changes a printing state of the print head according to the distance information obtained by the distance measuring unit. .

In one embodiment of the present invention, in an ink jet recording apparatus, a print head supplies ink to an ink ejection electrode, a bias voltage supply unit for supplying a bias voltage to the ink ejection electrode, and ink. An ink supply unit, comprising a recording voltage supply unit that selectively supplies a recording voltage to the ink ejection electrode, when a recording voltage superimposed on the bias voltage is supplied to the ink ejection electrode,
Ink is ejected from the ink ejection electrode to the print in accordance with the recording voltage.

In another embodiment of the present invention, in an ink jet recording apparatus, a print head includes an ink ejection electrode, an ink ejection electrode, and a print head arranged in front of the ink ejection electrode and having an opening at a portion facing the tip of the ink ejection electrode. A control electrode;
A bias voltage supply unit that supplies a different bias voltage to the ink ejection electrode and the control electrode; an ink supply unit that supplies ink to the ink ejection electrode; and a recording voltage supply unit that selectively supplies a recording voltage to the ink ejection electrode. When a recording voltage superimposed on a bias voltage is supplied to the ink ejection electrode, the ink is ejected from the ink ejection electrode to the print through the opening of the control electrode in accordance with the recording voltage.

[0013] In one specific example of one or another embodiment of the present invention, the ink-jet recording apparatus changes the printing state of the print head in accordance with the distance information obtained by the distance measuring unit. Is performed by changing the amplitude value.

[0014] In another specific example of one or another embodiment of the present invention, the ink jet recording apparatus changes the printing state of the print head in accordance with the distance information obtained by the distance measuring unit. And the amplitude value of the recording voltage.

[0015] In still another specific example of one or another embodiment of the present invention, the ink jet recording apparatus changes the print state of the print head in accordance with the distance information obtained by the distance measurement unit. This is done by changing the distance between the print head and the print head to the original distance.

According to each of these embodiments of the present invention, the movable arm is moved under the control of the control device when the ink jet print head is attached to the tip end,
When the inkjet print head is moved to a preset print area on the surface of a printed material in accordance with input data that has been input in advance, every time the movement is performed, the print head is printed by a distance measuring unit disposed inside. Measure the distance between the head and the printed matter, the control device changes the printing state by the print head according to the measurement result of the distance measurement unit, for example, or change the amplitude width of the recording voltage corresponding to the measurement result, By changing the voltage value of the bias voltage and the amplitude value of the recording voltage to change the ejection amount of the ink ejected from the print head, or without changing the ejection amount of the ink ejected from the print head. Since the distance between the print head and the printed matter is changed so as to be the original distance, even if the printed matter has a three-dimensional structure, the printing is always performed. It is possible to perform printing of good quality at the object surface.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of an ink jet recording apparatus according to the present invention, which constitutes a robot type ink jet recording apparatus, and shows an example in which printing (painting) is performed on the body of an automobile. Things.

In FIG. 1, 1 is a control device, 2 is a movable (robot) arm, 3 is an ink jet print head,
4 is a pedestal, 5 is a main body, 6 is a movable arm controller, 7 is an arm, 8 is a support, 9 is a wrist, 10 is a first joint, 11 is a second joint, and 12 is a third joint. An articulation portion, 13 is a tip portion, and 14 is an ink supply hose.

The control device 1 comprises a pedestal part 4, a main body part 5 rotatably supported on the pedestal part 4, and a movable arm control part 6 connected to the pedestal part 4 by a connection line. . Further, the movable arm 2 is provided with a first arm fixed to the main body 5.
A joint part 10, a support part 8 pivotally supported at one end by the first joint part 10, a second joint part 11 fixed to the other end of the support part 8, An arm 7 pivotally supported by the two joints 11, a wrist 9 fixed to the other end of the arm 7, a third joint 12 pivotally supported at one end by the wrist 9, A tip 13 is fixed to the other end of the third joint 12, and the inkjet print head 3 is attached to the other end of the tip 13. Further, one end of the ink supply hose 14 has an ink supply tank (not shown).
The other end is connected to the ink jet print head 3 through the second joint 11, the arm 7, the wrist 9, the third joint 12, and the tip 13, respectively.

In the ink jet recording apparatus having the above configuration, the position of the ink jet print head 3 is three-dimensionally moved by the movement of the movable arm 2. In the control device 1, the main body 5 is rotatable with respect to the base 4. In the movable arm 2, the support portion 8 is rotatably supported by the first joint portion 10, and the arm portion 7 is supported by the second joint portion 11.
Are rotatably supported by the third joint portion 12 and rotatably supported by the wrist portion 9. By appropriately controlling the rotation state and the rotation state, the movable arm 2 Ink jet print head 3 attached to tip 9
The moving position and the moving angle of can be changed freely. In this case, the control of the rotation state and the rotation state is performed according to a predetermined operation procedure based on data input to the movable arm control unit 6,
The ink is supplied from the ink supply tank to the ink jet print head 3 through the ink supply hose 14, and required printing is performed.

FIG. 2 is a schematic diagram showing an example of the configuration of an ink jet print head used in the ink jet recording apparatus of the present invention.

In FIG. 2, reference numeral 15 denotes a printed matter (vehicle body), 16 denotes an ink jet head, 17 denotes an ink supply unit, 18 denotes a distance measuring unit, 19 denotes an ink jet control unit, and other components shown in FIG. The same reference numerals are given to the same constituent elements as the elements.

The ink-jet print head 3 is used for the printed matter 1
The inkjet head unit 16 ejects ink toward the ink jet head 5, a distance measuring unit 18 that measures the distance between the inkjet print head 3 and the printed matter 15, and outputs the measurement result as distance information. And an ink supply unit 17 for temporarily accumulating the collected ink and supplying the ink to the inkjet head unit 16 as appropriate. The ink jet control unit 19 is disposed in the movable arm control unit 6 and, based on print data to be printed and distance information supplied from the distance measuring unit 18, as described later, an ink jet print head Change the printing condition of No. 3.

FIG. 3 is a schematic diagram showing an example of the details of the configuration of the ink jet head unit and the ink supply unit in the ink jet recording apparatus shown in FIG.

In FIG. 3, reference numeral 20 denotes an ink tank;
Denotes an ink carrier, 22 denotes an ink flow rate adjuster, and other components which are the same as those shown in FIG. 2 are denoted by the same reference numerals.

The ink supply unit 17 includes an ink supply hose 1
An ink tank 20 for temporarily storing the ink supplied through the ink tank 4, an ink carrier 21 for returning the remaining amount of ink used for printing by the inkjet head unit 16 to the ink tank 20, Flow rate adjusting body 22 for supplying ink to the inkjet head unit 16
The ink flow rate adjusting body 22 is configured by a pressurizing device such as a pump, a valve device, and the like.

In the ink supply unit 17, the ink stored in the ink tank 20 is supplied to an ink flow control unit 22.
A suitable amount is supplied to the inkjet head unit 16, and a part of the ink is
The remaining ink that is discharged from the printer to the printed material 15 and used for printing is returned to the ink tank 20 through the carrier 21 and supplied to the inkjet head unit 16 again.

FIGS. 4A and 4B are schematic views showing an example of a detailed configuration of the ink jet head unit and the ink jet control unit in the ink jet recording apparatus shown in FIG. 3 is an overall configuration diagram, and FIG. 3B is a detailed configuration diagram of a part of the inkjet control unit 19.

4 (a) and 4 (b), reference numeral 23 denotes a discharge electrode, 24 denotes a guide member, 25 denotes an electrode substrate, 26 denotes a spacer, 27 denotes a first control electrode, 28 denotes a second control electrode,
9 is a counter control electrode, 30 is a voltage corrector, 31 is a data converter, 32 is a pulse driver, 33 is a variable bias power supply,
Numeral 34 denotes a pulse generation source, and other components that are the same as those shown in FIG.

In the ink-jet head unit 16, the electrode substrates 25 and the spacers 26 are alternately laminated, and each electrode substrate 2
5 has a ribbon-shaped discharge electrode 23 and guide members 24 on both sides thereof. in this case,
The metallic print 15 is at ground potential. First control electrode 2
A constant voltage is applied to each of the seventh and second control electrodes 28.

The inkjet control unit 19 is supplied with the distance information measured by the distance measuring unit 18, supplied with a voltage correction unit 30 for outputting a control voltage, and supplied with data for printing on the printed matter 15. A data conversion unit 31 that outputs print data, a control voltage from the voltage correction unit 30 and print data from the data conversion unit 31 are supplied,
A pulse drive unit 32 that outputs an amplitude control signal corresponding to the control voltage and the print data; a variable bias power supply 33 whose output bias voltage value is adjusted by the control voltage from the voltage correction unit 30; A pulse generator 34 that outputs a variable amplitude pulse according to an amplitude control signal
And is constituted by. The pulse generation source 34 applies the pulse generation source 3 to the output bias voltage of the variable bias power supply 33.
The output on which the four output pulses are superimposed is supplied to the ejection electrode 23.

The operation of the ink jet recording apparatus according to the present embodiment having the above-described configuration will be described with reference to FIGS.
This will be described with reference to FIG.

When any printing (including a shape and a pattern) or painting is performed on the metallic printed matter 15, a control signal according to a program registered in advance in the movable arm controller 6 is supplied to the main body 5. Then, the main body unit 5 supplies the control signal to the movable arm 2 to move the movable arm 2 according to the control signal. In this case, the movable arm 2 is movable
Angle adjustment of the support part 8 by adjustment of the first joint part 10, second
The adjustment of the angle of the arm 7 with respect to the support 8 by adjusting the joint 11 and the angle of the tip 13 with respect to the arm 7 by adjusting the third joint 12 are performed.
The ink jet print head 3 attached to 3 moves to a position close to the metallic print 15.

At this time, data for printing is supplied to the ink jet control unit 19 in accordance with a program previously registered in the movable arm control unit 6. The ink jet control unit 19 converts the data supplied from the data conversion unit 31 into print data suitable for printing and sends the print data to the pulse drive unit 32, and converts the print data supplied from the pulse drive unit 32 into a corresponding pulse width control. The pulse signal is converted into a signal and sent to the pulse generation source 34, and a pulse signal having a pulse width corresponding to the pulse width control signal supplied from the pulse generation source 34 is generated.

This pulse signal is supplied to the variable bias power supply 33
Is supplied to the ejection electrode 23 of the inkjet head unit 16 while being superimposed on the bias voltage output from the inkjet head unit 16. In this case, the ink jet head 16 discharges ink flowing toward the tip of the discharge electrode 23 toward the metal print 15 by an electrostatic force obtained by a voltage applied between the discharge electrode 23 and the metal print 15. The ink jet head operates by a so-called electrostatic suction method, and the metallic print 15
A small amount of ink is ejected toward the metallic printed matter 15
A predetermined printing is performed by adhering ink droplets to the surface of the printer.

The ink used in the ink jet recording apparatus according to the present embodiment is formed by dispersing a chargeable colorant in an insulating solvent. The ink is supplied to the ink-jet head 16 via the nozzle 22 and flows in the ink-jet head 16 in the direction indicated by the arrows in FIGS. 4A and 4B. At this time, the inkjet head 1
6, the thickness of the spacer 26 is set to 0.1 to 0.3.
mm and the spacer 26
If the width of the step between the substrate and the electrode substrate 25 is selected so as to be in the range of 0.1 to 0.3 mm in the same manner as the thickness of the spacer 26, the ink flows in the inkjet head unit 16 in a stable state. Become. In this case, the number of stacked layers of the electrode substrate 25 and the spacer 26 constituting the inkjet head unit 16 varies depending on the type and use of the inkjet recording apparatus, but it is usually preferable to select a number of steps from 20 to 200.

In the ink-jet head section 16, the voltage applied to the first control electrode 27 and the second control electrode 28 and the bias voltage applied to the ejection electrode 23 are always applied to the ink. It flows through the action of the electrostatic field created by the voltage. The charged colorant in the ink aggregates at the tip of the discharge electrode 23 due to the electrostatic field. That is, the electrostatic field is generated by the first control electrode 27 and the second control electrode 28.
, And from the downstream of the ink flow path to the upstream direction, the colorant in the ink is most aggregated at the tip of the discharge electrode 23 by electrostatic force. In this case, the voltage applied to the first control electrode 27 is
The voltage applied is about 100 to 200 V higher than the bias voltage, and the voltage applied to the second control electrode 28 is an intermediate voltage between the bias voltage and the first control electrode 27. It is.

When only these voltages are applied, the ink jet head 16 is used to
Ink is not ejected from the tip of the nozzle 5, but when a pulse signal is applied to the ejection electrode 25 from the pulse generation source 34 in addition to these voltages, the ejection electrode 25 is applied only during the period when the pulse signal is applied. The ink forms a thread from the tip and flies toward the metallic print 15 and adheres to the surface of the metallic print 15. The amount of ink flying at this time increases as the pulse width of the pulse signal supplied from the pulse generation source 34 increases, and the diameter of the ink dots adhering to the surface of the metallic print 15 increases.

As described above, the ink jet recording apparatus of this embodiment can perform high-definition printing because different size steps are provided for each ink dot at the time of printing. A recorded image can be obtained.

When the ink jet print head 3 is moved by using the movable arm 2 as in the ink jet recording apparatus of the present embodiment, the printing state changes depending on the positioning accuracy of the movable arm 2 and extremely. In such a case, a situation may occur in which the ejected ink does not reach the metallic printed matter 15, and predetermined printing may not be performed.

Therefore, the ink jet recording apparatus of this embodiment measures the distance between the ink jet print head 3 and the metallic print 15 in the ink jet print head 3, and indicates the distance indicating the degree of separation from the original distance. A distance measuring unit 18 for generating information is provided.
It detects that the distance (distance) between the inkjet print head 3 and the metallic print 15 has fluctuated from a specified value based on the distance information constantly output from the printer, and changes the printing state according to the detection result. Thus, predetermined printing can be always performed without changing the printing quality.

That is, the distance information obtained by the distance measurement unit 18 is supplied to the voltage correction unit 30 of the ink jet control unit 19, and the voltage correction unit 30 generates two control voltages corresponding to the distance information. One control voltage is supplied to the variable bias power supply 33,
Is adjusted, and the other control voltage is supplied to the pulse driving unit 32 to change the amplitude control signal generated by the pulse driving unit 32, and the pulse signal generated from the pulse generation source 34 Adjust the pulse amplitude of.

Here, when the distance information obtained by the distance measuring unit 18 is distance information indicating that the distance is equal to the original distance, the voltage correcting unit 30 determines the voltage value of the bias voltage generated by the variable bias power supply 33. One control voltage that does not change is generated, and the other control voltage that does not change the pulse amplitude of the pulse signal generated from the pulse generation source is generated. When the distance information indicates that the distance information is larger than the original distance, the voltage correction unit 30 increases the voltage value of the bias voltage generated by the variable bias power supply 33 in proportion to the difference. And the other control voltage is generated so as to increase the pulse amplitude of the pulse signal generated from the pulse generation source 34 in proportion to the difference. On the other hand, when the distance information is smaller than the original distance, the voltage corrector 30 reduces the voltage value of the bias voltage generated by the variable bias power supply 33 in proportion to the difference. And the other control voltage is generated such that the pulse width of the pulse signal generated from the pulse generation source 34 is reduced in proportion to the difference.
At this time, it is preferable that the variable range of the voltage value of the bias voltage generated by the variable bias power supply 33 is adjusted between 2 and 3 KV, and the variable range of the amplitude value of the pulse signal is adjusted between 200 and 1000 V. However, it is desirable that the amplitude value of the pulse signal be selected to be as small as possible, since the response speed at the time of ON / OFF is improved by selecting a small value.

As described above, according to the ink jet recording apparatus of this embodiment, at the time of printing, the distance between the ink jet print head 3 and the metallic print 15 is originally based on the distance information constantly output from the distance measuring unit 18. Is detected, and the flying amount of the ink is changed in accordance with the detection result, so that the predetermined printing can be always performed without changing the printing quality.

In the ink jet recording apparatus according to the present embodiment, the variable bias power supply 33 corresponds to the distance information.
Of the bias voltage generated by the pulse generator 34 and the pulse generator 34
Although the example in which the pulse amplitude of the pulse signal generated by the pulse generation is adjusted has been described above, only the pulse amplitude of the pulse signal generated by the pulse generation source 34 may be adjusted in accordance with the distance information. , To a lesser extent,
By changing the flying amount of the ink, predetermined printing can always be performed without changing the printing quality.

Next, FIGS. 5A, 5B and 5C are explanatory views showing the principle of distance measurement by the distance measuring section 18 used in the ink jet recording apparatus of the present invention. (B) is when the interval is larger than the original interval, and (c) is when the interval is smaller than the original interval. .

In FIGS. 5A, 5B and 5C, 3
Reference numerals 5, 36, 37 and 38 denote lenses, reference numerals 39 and 40 denote position detectors, and other components which are the same as those shown in FIG.

The distance measuring section 18 of this embodiment uses a distance measuring method used in an autofocus camera, and the lens 35 can be appropriately moved in the axial direction of the lens. Now, as shown in FIG. 5A, when the distance between the inkjet print head 3 and the printed matter 15 is equal to the original distance, the light emitted from the printed matter 15 forms an image on the lens 35, and then, The light passing through the lens 36 is re-imaged on the position detector 39 by the lens 37 and on the position detector 40 by the lens 38. Here, as shown in FIG. 5B, when the distance between the inkjet print head 3 and the printed matter 15 is larger than the original distance, that is, the distance between the lens 35 and the printed matter 15 is longer than the original distance. In this case, when the distance between the two image forming points is widened, and conversely, as shown in FIG. 5C, when the distance between the inkjet print head 3 and the printed matter 15 is smaller than the original distance, That is, the lens 35 and the printed matter 15
Is smaller than the original distance, 2
The distance between two imaging points is reduced. The image formation positions on the two position detectors 39 and 40 are exactly the same as the printed matter 15
By controlling the position of the lens 35 so that the image is formed on the two position detectors 39 and 40, the position of the lens 35 at the time when the two position The distance between the print head 3 and the printed matter 15 can be obtained. If the surface of the printed matter 15 is smooth and it is difficult to achieve focus, the printed matter 15 may be irradiated with pattern light, and the reflected light obtained at this time may be imaged.

As the distance measuring section 18 of this embodiment, in addition to the distance measuring method used in the autofocus camera, a method using optical means used in a general camera, or a method using an ultrasonic wave is used. Methods such as the knife edge method, the critical angle method, the astigmatic difference method, etc., which are usually used for detecting the autofocus of the optical head for optical disks, or the displacement measuring method such as the triangulation method. Can be used.

In the ink jet of this embodiment, an ink jet print head 3 and a spray gun are attached to the tip 13 of the movable arm 2 so that printing is performed by the ink jet print head 3 and painting is performed by the spray gun. It may be. Further, if necessary, a fixing process such as drying of the ink on the printed matter 15 and printing of an image formed on the printed matter 15 can be performed. Furthermore, when printing on the printed matter 15 made of a non-metallic body, the printed matter 15 is subjected to plating treatment or vacuum deposition in advance to form a metal film on the surface, and this metal film is used as an electrode,
What is necessary is just to print on the surface of this metal film.

Next, FIG. 6 is a schematic diagram showing another example of the configuration of the ink jet print head used in the ink jet recording apparatus of the present invention, and shows another embodiment of the ink jet recording apparatus.

In FIG. 6, reference numeral 41 denotes a moving unit, 42 denotes a linear motor, 43 denotes a slider, 44 denotes a linear motor control unit, 45 denotes a linear motor driving unit.
The same components as those shown in FIG. 2 are denoted by the same reference numerals.

The ink jet head section 16, the ink supply section 17, and the distance measuring section 18 are mounted on a moving section 41, and the moving section 41 is connected to a linear motor 42.
It is configured to be able to move as appropriate along the slider 43. The movement of the linear motor 42 is performed by driving the linear motor drive unit 45 based on the control of the linear motor control unit 44.

In the ink jet recording apparatus of this embodiment, the ejection electrodes 2 correspond to the distance information obtained by the distance measuring section 18.
The distance between the ink jet print head unit 3 and the printed matter 15 is adjusted so that the distance information becomes the original distance information instead of changing the amount of ink flying from the ink jet head 3. When the distance information measured by the distance measuring unit 18 is supplied to the linear motor control unit 44, the linear motor control unit 44 sends a control signal corresponding to the supplied distance information to the linear motor driving unit 45, The linear motor driving unit 45 moves the linear motor 42 in response to the supplied control signal.

That is, when the distance information obtained by the distance measuring unit 18 is the distance information indicating that the distance is equal to the original distance, the linear motor control unit 44 controls the linear motor driving unit 45 so that the linear motor 42 is not moved. Generate a control voltage. When the distance information is larger than the original distance, the linear motor controller 44
The linear motor driving unit 45 moves the moving unit 41 in the direction of the printed matter 15 via the linear motor 42, and generates a control voltage such that the distance information becomes distance information indicating that the distance information is equal to the original distance. On the other hand, when the distance information is smaller than the original distance, the linear motor controller 44
Generates a control voltage such that the linear motor driving unit 45 moves the moving unit 41 via the linear motor 42 in the direction opposite to the direction of the printed matter 15 and the distance information becomes distance information indicating that the distance information is equal to the original distance. .

As described above, according to the ink jet recording apparatus of this embodiment, when the distance information is different from the original distance information, the distance between the ink jet print head unit 3 and the printed matter 15 is originally determined by using the distance information. , The predetermined printing can always be performed without changing the printing quality.

In the ink jet recording apparatus of this embodiment, when the moving section 41 is moved, instead of using the linear motor 42, an actuator such as a worm gear that moves the moving section 41 linearly is used. Is also good.

Also in the ink jet recording apparatus of this embodiment, the ink jet print head 3 and the spray gun are attached to the distal end portion 13 of the movable arm 2 to perform printing with the ink jet print head 3 and at the same time paint with the spray gun. May be performed.

FIG. 7 is a schematic diagram showing another configuration of the ink jet print head 3 used in the ink jet recording apparatus of the present invention. The inkjet head unit 16 is divided into blocks, and can be moved individually for each block.

In FIG. 7, the same components as those shown in FIG. 6 are denoted by the same reference numerals.

The ink jet print head 3 of the present embodiment
In each block, the moving unit 41 is provided with the inkjet head unit 16 and the distance measuring unit 18, and the moving unit 41 is coupled with the linear motor 42, and is driven by the linear motor 42. It is configured to be movable as appropriate along the slider 43.

According to the ink jet print head 3 of this embodiment, even when the surface of the printed matter 15 has irregularities,
Since each block can be appropriately moved by driving the linear motor 42, the position of the ink jet print head 3 can be adjusted according to the unevenness on the surface of the printed matter 15.

The ink jet print head 3 of this embodiment
In the above, instead of performing the movement by the linear motor 42 for each block, the amplitude value of the pulse signal applied to the ejection electrode 23 is changed for each block, or the bias voltage applied to the ejection electrode 23 for each block is changed. The voltage value and the amplitude value of the pulse signal may be changed.

FIGS. 8A and 8B are schematic views showing the state near the ejection electrode of the ink jet head unit 16 of another configuration used in the ink jet recording apparatus of the present invention. 8A is a cross-sectional view, FIG. 8B is a perspective view, and FIG. 9 is a cross-sectional view of the inkjet head unit 16 shown in FIG.

8 (a), 8 (b) and FIG.
9H is an opening of the opposing control electrode 29, 46 is ink, 47 is an ink flow path, and the same components as those shown in FIGS. 4A and 4B are denoted by the same reference numerals. .

As shown in FIGS. 8A and 8B, an opening 2 is formed in the opposing control electrode 29 near the tip of the discharge electrode 23.
9H is provided, and the ink flying from the tip of the discharge electrode 23 is attached to the printed matter 15 through the opening 29H. The variable bias power supply 33 is divided into two, the opposing control electrode 29 is applied with a bias voltage from one variable bias power supply 33, and the ejection electrode 23 is superimposed with the bias voltage from one and the other variable bias power supply 33. Applied. Guide members 24 connected to the ground on both sides of the discharge electrodes 23 are arranged to reduce crosstalk between adjacent discharge electrodes 23. The tip of the discharge electrode 23 is rounded with a radius of curvature of 30 to 60 μm, and the electric field is concentrated at the tip. Ink 46
Flows between the electrode substrate 25 and the guide member 24 as indicated by the arrow in the figure.

As shown in FIG. 9, the opening 29H of the opposing control electrode 29 has a slit shape and is provided so as to be substantially orthogonal to the ink flow path 47.

In the ink jet head unit 16 having such a configuration, the ink 46 that has reached the tip of the ejection electrode 23 mainly senses an electrostatic field formed by the potential difference between the ejection electrode 23 and the opposing control electrode 29, When a pulse signal is supplied from the pulse generation source 34 superimposed on the bias voltage from the variable bias power supply 33 and the electric field strength of the electrostatic field exceeds the critical electric field strength, ink is ejected from the ejection electrode 23 and the ejection is performed. The printed ink flies toward the printed matter 15 due to the electric field between the opposing control electrode 29 and the printed matter 15 and printing is performed.

In the above embodiments, the printed matter 15
Has been described with reference to an example in which an automobile body is used. However, when the printed matter 15 by the inkjet recording apparatus of the present invention is not limited to an automobile body and is printed on a printed matter having another three-dimensional structure, for example, a metal film is formed. The present invention can be applied to tableware, accessories, and patterns for houses (brick patterns, tile patterns, and the like), and similarly, can be applied to flat printed matter.

[0071]

As described above, according to the present invention, the movable arm is moved under the control of the control device after the ink jet print head is attached to the tip, and the ink jet print head is moved in accordance with the input data input in advance. When the print head is moved to a preset printing position, the print head measures the distance between the print head and the printed matter by a distance measuring unit disposed inside each time the movement is performed, and the control device Changing the printing state of the print head according to the measurement result of the distance measurement unit, for example, changing the amplitude value of the recording voltage or changing the voltage value of the bias voltage and the amplitude of the recording voltage according to the measurement result. To change the amount of ink ejected from the print head, or print without changing the amount of ink ejected from the print head. Since the distance between the head and the printed matter is changed so as to be the original distance, even if the printed matter has a three-dimensional structure, good quality printing can always be performed on the surface of the printed matter. This has the effect.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embodiment of an ink jet recording apparatus according to the present invention.

FIG. 2 is a schematic diagram showing an example of a configuration of an ink jet print head used in the ink jet recording apparatus of the present invention.

FIG. 3 is an outline diagram illustrating an example of a detailed configuration of an inkjet head unit and an ink supply unit in the inkjet recording apparatus illustrated in FIG. 2;

4 is an outline diagram illustrating an example of a detailed configuration of an inkjet head unit and an inkjet control unit in the inkjet recording apparatus illustrated in FIG.

FIG. 5 is an explanatory diagram showing a principle of distance measurement of a distance measuring unit used in the ink jet recording apparatus according to the present invention.

FIG. 6 is an outline diagram showing another example of the configuration of the ink jet print head used in the ink jet recording apparatus of the present invention.

FIG. 7 is an outline diagram showing another configuration of the ink jet print head used in the ink jet recording apparatus of the present invention.

FIG. 8 is a schematic diagram showing a state near an ejection electrode of an inkjet head having another configuration used in the inkjet recording apparatus of the present invention.

FIG. 9 is a cross-sectional view of the inkjet head section shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control apparatus 2 Movable (robot) arm 3 Ink-jet print head 4 Pedestal part 5 Main part 6 Movable arm control part 7 Arm part 8 Support part 9 Wrist part 10 First joint part 11 Second joint part 12 Third joint part 13 Tip Unit 14 Ink supply hose 15 Printed matter (metallic printed matter) 16 Inkjet head unit 17 Ink supply unit 18 Distance measurement unit 19 Inkjet control unit 20 Ink tank 21 Ink carrier 22 Ink flow rate adjustment unit 23 Discharge electrode 24 Guide member 25 Electrode substrate 26 Spacer 27 First control electrode 28 Second control electrode 29 Opposing control electrode 29H opening 30 Voltage correction unit 31 Data conversion unit 32 Pulse driving unit 33 Variable bias power supply 34 Pulse generation source 35, 36, 37, 38 Lens 39, 40 Position detection Container 41 Moving unit 42 Linear mode Over 43 slider 44 linear motor control unit 45 the linear motor drive unit 46 the ink 47 ink passage

Claims (6)

[Claims] 1. An ink jet recording apparatus comprising: a movable arm having an ink jet print head at a distal end thereof; and a control device for holding the movable arm and moving the movable arm, wherein the print head includes the print head and a printed material. Equipped with a distance measuring unit that measures the distance between
The ink jet recording apparatus according to claim 1, wherein the control device changes a printing state of the print head in accordance with the distance information obtained by the distance measuring section. 2. The print head, comprising: an ink discharge electrode;
A bias voltage supply unit that supplies a bias voltage to the ink ejection electrode; an ink supply unit that supplies ink to the ink ejection electrode; and a recording voltage supply unit that selectively supplies a recording voltage to the ink ejection electrode. Wherein, when the recording voltage superimposed on the bias voltage is supplied to the ink ejection electrode, ink is ejected from the ink ejection electrode to a print in accordance with the recording voltage. The ink-jet recording apparatus according to claim 1. 3. The print head according to claim 1, wherein the print head includes an ink discharge electrode;
A counter control electrode disposed in front of the ink discharge electrode and having an opening at a portion facing the tip of the ink discharge electrode, a bias voltage supply unit that supplies different bias voltages to the ink discharge electrode and the control electrode, An ink supply unit that supplies ink to the ink ejection electrode; and a recording voltage supply unit that selectively supplies a recording voltage to the ink ejection electrode, wherein the recording voltage superimposed on the ink ejection electrode with the bias voltage is provided. 2. The ink jet recording apparatus according to claim 1, wherein when the ink is supplied, ink is ejected from the ink ejection electrode to a print through an opening of the control electrode in accordance with the recording voltage. . 4. The method according to claim 1, wherein the change of the printing state of the print head changes an amplitude value of the recording voltage in accordance with the distance information obtained by the distance measuring unit. 3. The inkjet recording apparatus according to any one of 3. 5. The method according to claim 1, wherein changing the printing state of the print head includes changing a voltage value of the bias voltage and an amplitude value of the recording voltage in accordance with the distance information obtained by the distance measuring unit. The ink jet recording apparatus according to claim 1, wherein: 6. A method of changing a printing state of the print head so that an interval between the print body and the print head becomes an original interval in accordance with distance information obtained by the distance measuring unit. The inkjet recording apparatus according to claim 1, wherein: