JP3212062B2 - Ink jet device - Google Patents

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 an ink-jet recording apparatus for executing a simple high-speed printing mode without missing dots.

[0002]

2. Description of the Related Art Among non-impact print heads, which are replacing the impact type print heads and expanding the market, the principle is the simplest and the multi-gradation print head is available. An ink jet print head is one that is easy to colorize.
Above all, the drop-on-demand type, which ejects only ink droplets used for printing, is rapidly spreading due to its good ejection efficiency and low running cost.

The Kaiser type disclosed in Japanese Patent Publication No. 53-12138 as a drop-on-demand type,
Alternatively, a thermal jet type disclosed in Japanese Patent Publication No. 61-59914 is a typical method.
However, among them, the former is difficult to miniaturize, and the latter requires a heat resistance of the ink to apply high heat to the ink, and each has a very difficult problem. Therefore, an ink jet recording apparatus using a shear mode type printing head disclosed in Japanese Patent Application Laid-Open No. 63-247051 has been proposed as a new method for solving the above-mentioned defects at the same time.

In such an ink jet recording apparatus, in general, a normal print mode in which ink droplets are ejected from nozzles in a one-to-one correspondence with each dot print signal in print data to perform printing, and a print head in a normal print mode. The so-called high-speed printing mode, in which ink droplets are ejected from nozzles while printing is performed while thinning a predetermined number of dots from the total number of dots printed based on each dot printing signal while moving on the paper surface at high speed, It is selectable.

[0005]

However, in the high-speed printing mode performed in the above-described conventional ink jet recording apparatus, there are the following problems. That is, in the above-described conventional ink jet recording apparatus, the pitch between dots is the same in the main scanning direction and the sub scanning direction as shown in FIG. Therefore, when performing high-speed printing mode, it will simply empty occurs white spots as shown in FIG. 15 between the thinned out print data at every other dot dot occurs. Further, in order to prevent the white spots and execute the high-speed printing mode, complicated processing is required, which causes an increase in the cost of the ink jet recording apparatus itself.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet recording apparatus capable of printing at high speed without causing white spots in dots constituting characters and the like.

[0007]

According to a first aspect of the present invention, there is provided an ink jet recording apparatus, comprising: an ink jet head having a plurality of nozzles for ejecting ink droplets from each nozzle; Pulse signal output means for outputting a pulse signal based on each dot print signal in the print data including the signal, and a plurality of ink droplet landing positions different from each other corresponding to one pulse signal output from the pulse signal output means . A first print mode for outputting a plurality of drive signals for ejecting ink droplets and a drive signal for ejecting a smaller number of ink droplets than the number of drive signals for the first print mode in response to one pulse signal. A print mode switching means for selecting a second print mode to be output, and the plurality of drives when the first print mode is selected by the print mode switching means. Ink droplets from each nozzle on the basis of the causes plural ejecting ink droplets from the nozzles, the number of drive signals less than the first printing mode when the second printing mode is selected by the print mode switching means based on the No. and drive means for ejecting said moving said ink jet head and the recording medium when the first print mode is selected by the printing mode switching means at a relatively first speed, the printing mode switching means second print mode A head scanning unit for relatively moving the ink jet head and the recording medium at a second speed higher than the first speed when selected.

According to a second aspect, the pulse signal output means outputs the pulse signal in the second print mode to the first signal.
The pulse signal is output at 1 / N times the output period of the pulse signal in the printing mode, and the head runner sets the second speed to N times the first speed.

[0009] According to claim 3, the amount of the ink droplets ejected before Symbol second printing mode is characterized by greater than the amount of ink droplets at the time of the first printing mode.

[0010]

In the ink jet recording apparatus of the present invention having the above configuration, first, the first print mode or the second print mode is selected via the print mode switching means. When the first print mode is selected by the print mode switching means, a plurality of ink droplet landing positions corresponding to one pulse signal output from the pulse output means based on each dot print signal in the print data are different . Eject ink drops
A driving signal is output, and ink droplets are ejected from each nozzle by the driving means based on the driving signal. The head scanning means relatively moves the ink jet head and the recording medium.

When the first printing mode is selected, the ink jet head and the recording medium are relatively moved at the first speed by the head scanning means, and each nozzle is moved in response to one pulse signal. A plurality of ink droplets having different landing positions are ejected, and characters and the like are printed with high quality.

When the second print mode is selected by the print mode selecting means, unlike the above, the first print mode corresponding to one pulse signal output from the pulse output means based on each dot print signal. The number of drive signals smaller than the number of drive signals is output, and ink droplets are ejected from each nozzle by the drive means based on the drive signals.

The head scanning means moves the ink jet head and the recording medium at a second speed higher than the first speed. Thus, when the second print mode is selected, one ink droplet is ejected from each nozzle in response to a smaller number of drive signals than in the first print mode, and the inkjet head scans at high speed. As a result, printing can be performed at high speed without causing white spots on dots constituting characters and the like.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 4, the piezoelectric ink jet head 1 includes a piezoelectric ceramic plate 2, a cover plate 3, a nozzle plate 4, and a manifold member 18. The piezoelectric ceramic plate 2 is formed of a ceramic material such as lead zirconate titanate (PZT), and has a plurality of lateral grooves 21 cut by a diamond blade or the like.
In addition, the partition 22 which is the side surface of the lateral groove 21 is polarized in the direction of arrow A. The lateral grooves 21 are parallel to each other at the same depth, and are processed so as to open from the opposing end surface 23a to the end surface 23b of the piezoelectric ceramic plate 2.

A longitudinal groove 25a is formed on the end face 23a of the piezoelectric ceramic plate 2 so as to communicate with the lateral groove 21.
Every other is formed. Piezoelectric ceramic plate 2
In the end face 23b, every other vertical groove 25b is formed so as to communicate with the horizontal groove 21. The vertical grooves 25a and the vertical grooves 25b are formed alternately, and the vertical grooves 25a and the vertical grooves 25b are formed in adjacent horizontal grooves 21. still,
The vertical grooves 25a are provided in the lateral grooves 21 on both outer sides. Further, patterns 5 and 6 are formed on the lower surface 24 of the piezoelectric ceramic plate 2 on the opposite side to the processing side of the lateral groove 21.

Metal electrodes 7, 8, and 9 are formed via sputtering or the like which is disposed obliquely above the grooved surface of the piezoelectric ceramic plate 2 and the end surface 23a. From the direction of).
It should be noted that masking is performed so that metal electrodes are not formed on the end face 23a of the piezoelectric ceramic plate 2 and the top of the partition wall 22. Then, as shown in FIG. 1, the metal electrode 7 is formed in the upper half area of both end faces of the lateral groove 21 and the metal electrode 8 is formed.
Is the end face 23 of the horizontal groove 21 in which the vertical groove 25a is not formed.
The metal electrode 9 is formed on a part of the side surface and the bottom surface on the side a, and the metal electrode 9 is formed on the end surface 23a side among the side surfaces of the vertical groove 25a. The metal electrode 7 and the metal electrode 8 are electrically connected, and the metal electrode 7 and the metal electrode 9 are electrically connected.

Next, as shown in FIG. 4, metal electrodes 10 and 11 are formed via sputtering or the like which is disposed obliquely above the lower surface 24 of the piezoelectric ceramic plate 2 and the end surface 23b. (Evaporated from the directions of arrows D and E). It should be noted that a mask is formed so that the metal electrodes are not formed in the regions where the patterns 5 and 6 are formed on the end surface 23b and the lower surface 24 of the piezoelectric ceramic plate 2. Then, the metal electrode 10 is located on the lower surface 24 of the piezoelectric ceramic plate 2 from the bottom surface of the vertical groove 25a to the end surface 23a.
And a part of the side surface of the inner surface of the vertical groove 25a. At this time, the metal electrode 10 is also formed on the metal electrode 9 formed in the vertical groove 25a, and the metal electrode 10 formed on the side surface of the vertical groove 25a is electrically connected to the metal electrode 7 via the metal electrode 9. Is done. For this reason, the metal electrode 7 formed on the partition 22 on one side of the horizontal groove 21a in which the vertical groove 25a is formed.
Is electrically connected to the metal electrode 7 formed on another partition 22 forming the horizontal groove 21b in another horizontal groove 21a sandwiching the horizontal groove 21b formed by the partition 22. Further, the metal electrode 10 is electrically connected to the pattern 5.

As shown in FIGS. 3 and 4, the metal electrode 11 is formed in the area of the end face 23b from the center of the piezoelectric ceramic plate 2, the entire inner side face of the vertical groove 25b, and the end face 23b of the horizontal groove 21a. Is done. At this time, the metal electrode 11 is also formed on the metal electrode 7 in the horizontal groove 21b communicating with the vertical groove 25b, and is electrically connected to the metal electrode 11 formed on the side surface of the vertical groove 25b. For this reason, the vertical groove 25
All the metal electrodes 7 in the lateral groove 21b in which b is formed are electrically connected by the metal electrode 11. In addition, metal electrode 1
1 is electrically connected to the pattern 6.

FIG. 5 is a sectional view of the piezoelectric ink jet head 1. As shown in FIG. 5, at least the metal electrodes 7 and the electrodes 8, 11 of the piezoelectric ceramic plate 2 are made of epoxy resin by spin coating. It is covered with the protective film 12.

Incidentally, the coating with the protective film may be performed by using the epoxy resin by the spin coating method, the dipping method, or the CV method.
It may be covered with a protective film of another organic material such as an acrylic resin or an inorganic material such as SiO2 by the method D or the like.

On the other hand, the metal electrode 9 and an air chamber 13 described later
Since the metal electrode 7 formed in the lateral groove 21a forming the contact is not in contact with the ink, it is not always necessary to cover the metal electrode 7 with the protective film 12.

Next, the cover plate 3 is formed of a ceramic material, a glass material, a resin material, or the like.
A surface of the piezoelectric ceramic plate 2 on the processing side of the lateral groove 21;
The cover plate 3 is bonded with an epoxy resin adhesive 14. Therefore, the upper surface of the horizontal groove 21 is covered in the piezoelectric ink jet head 1 to form an ink chamber 15 communicating with the vertical groove 25b and an air chamber 13 as a non-ejection device communicating with the vertical groove 25a. The ink chamber 15 corresponds to the lateral groove 21b, and the air chamber 13 corresponds to the lateral groove 21a. The ink chambers 15 and the air chambers 13 have an elongated shape with a rectangular cross section. All the ink chambers 15 are filled with ink, and the air chambers 13 are areas filled with air.

The ink chambers 15 are provided on the end face 23a of the piezoelectric ceramic plate 2 and the end face of the cover plate 3.
The nozzle plate 4 provided with the nozzles 41 is bonded at a position corresponding to the above. The nozzle 41 formed on the nozzle plate 4 includes a tapered portion 42 and an orifice portion 43 as shown in FIG. A water-repellent film is provided on the surface of the nozzle plate 4 on the ink ejection side. Also, 50 nozzles 41 are formed on the nozzle plate 4 at a pitch of l = 308 μm on a straight line.

The manifold member 18 is bonded to the end face 23b of the piezoelectric ceramic plate 2 and the lower surface 24 of the piezoelectric ceramic plate 2 on the side of the vertical groove 25b. A manifold 51 is formed on the manifold member 18, and the manifold 51 surrounds the vertical groove 25b.

The patterns 5 and 6 formed on the lower surface 24 of the piezoelectric ceramic plate 2 are connected to a wiring pattern of a flexible printed board (not shown). The wiring pattern of the flexible printed board is connected to a rigid board (not shown) connected to a control unit described later.

The piezoelectric ink jet head 1 is arranged as shown in the main part of the printer shown in FIG. The platen 61 is framed by a shaft 62
The platen motor 64 is rotatably mounted on the
Driven by The piezoelectric inkjet head 1 is provided so as to face the platen 61. The piezoelectric inkjet head 1 is mounted on a carriage 66 together with the ink cartridge 65. The carriage 66 is slidably supported by two guide rods 67, 67 disposed parallel to the axis of the platen 61, and the timing belt 6 wound around a pair of pulleys 68A, 68B.
9 are connected. Then, the pulley 68A is rotated by the carriage motor 70, and the timing
Is sent, the carriage 66 moves on the paper 71 along the platen 61.

Next, the configuration of the control unit will be described with reference to FIG. 8 which shows a block diagram of the control unit. The patterns 5 and 6 formed on the lower surface 24 of the piezoelectric ceramic plate 2 are individually connected to a drive circuit 81, a clock line 82 for transmitting a clock signal, and a data line for transmitting input print data in synchronization with the clock signal. 83, a fire clock signal line 96 for giving the ejection timing of the piezoelectric ink jet head 1, a voltage line 84 for applying a voltage, and an earth line 85 are also connected to the drive circuit 81. A clock line 8 having one end connected to the drive circuit 81
2. The other ends of the print data line 83 and the fire clock signal line 96 are connected to the microcomputer 86.

The microcomputer 86 has a panel 87 for inputting switching between a normal printing mode and a high-speed printing mode, and an R for temporarily storing data input from the panel 87.
AM 88, ROM 89 in which print patterns for print characters and the like are stored, and respective motor drivers 90 and 9
1, the platen motor 64 and the carriage motor 7
0, and a paper sensor 92 for detecting a deviation of the fed paper 71 in the main scanning direction or the sub-scanning direction, and an origin for detecting whether the scanning start position of the piezoelectric inkjet head 1 with respect to the paper 71 has returned to the origin. The sensor 93 is connected.

When the normal print mode is selected via the panel 87, the microcomputer 86 sends one print to the drive circuit 81 via the fire clock signal line 96 and the data line 83 as shown in FIG. Two fire signals (described later) are output for data transfer.

When the high-speed print mode is selected via the panel 87, the transfer cycle of the print data is reduced to 1/2 while the cycle of the fire signal is kept as shown in FIG.
To At the same time, the carriage motor 70 is rotated via the motor driver 91 so that the carriage 66 moves on the paper 71 along the platen 61 at twice the speed of the normal mode.

The driving circuit 81 further has the following configuration. FIG. 9 shows a block diagram of the drive circuit. In the drive circuit 81, the clock line 82 and the data line 83 are both connected to a converter 95, which converts a serial signal (dot print signal) transmitted from the data line 83 from the clock line 82. Is converted into a parallel signal based on the clock signal. Further, an output line 95 a corresponding to each nozzle 41 is connected to the converter 95, and each output line 95 a is connected to one input terminal of the AND circuit 97.

The other input terminal of each AND circuit 97 has
A fire clock signal line 96 for transferring a fire clock signal is connected. Here, each AND circuit 9
7 is parallelized by a converter 95 and output line 95a
And a fire clock signal output from the fire clock signal line 96, and calculates a fire signal (see FIG. 7) for a driver 98 provided for each nozzle 41. 10, see FIG. 12). Then, each driver 98 drives each nozzle 41 to eject an ink droplet by applying a predetermined voltage from a voltage line 84 to an electrode in each nozzle 41 based on a fire signal.

Next, the operation of the ink jet recording apparatus having the above configuration will be described. Ink chamber 1 shown in FIG.
5b, the ink chamber 15 is ejected.
A voltage pulse is applied to the metal electrodes 7c and 7f on the ink chamber 15b side of the air chambers 13b and 13c on both sides of b through the pattern 5, and to the other metal electrodes 7 through the other patterns 5 and 6 Ground. Then, as shown in FIG. 6, an electric field in the direction of arrow F is generated in the partition 22b, an electric field in the direction of arrow G is generated in the partition 22c, and the partitions 22b and 22c move away from each other. Then, the volume of the ink chamber 15b increases, and the pressure in the ink chamber 15b including the vicinity of the nozzle 41 decreases. This state is maintained for a time indicated by L / a. Then, ink is supplied from the manifold 51 to the ink chamber 15b through the vertical groove 25b. still,
The above L / a indicates that the pressure wave in the ink chamber 15 is
5 is a time required for one-way propagation in the longitudinal direction (from the vertical groove 25b to the nozzle plate 4 or vice versa), and is determined by the length L of the ink chamber 15 and the sound velocity a in the ink. .

According to the pressure wave propagation theory, the pressure in the ink chamber 15b reverses and changes to a positive pressure when the time of L / a elapses from the start-up, but the electrode is included in this timing. The voltage applied to 7c and 7f is returned to 0V. Then, the partition walls 22b and 22c return to the state before deformation (FIG. 5), and pressure is applied to the ink. At this time, the pressure turned forward and the pressure generated by the partition walls 22b and 22c returning to the state before the deformation are combined, and a relatively high pressure is applied to the ink in the ink chamber 15b, and the ink droplet is discharged from the nozzle 41. It is gushing.

In the above embodiment, first, the drive voltage is applied in the direction in which the volume of the ink chamber 15b increases, and then the application of the drive voltage is stopped to reduce the volume of the ink chamber 15b to a natural state. Although ink droplets were ejected from the ink chamber 15b, first, a drive voltage was applied so as to reduce the volume of the ink chamber 15b to eject ink drops from the ink chamber 15b, and then application of the drive voltage was stopped. The ink may be supplied into the ink chamber 15b by increasing the volume of the ink chamber 15b from the reduced state to the natural state.

Next, the drive control for driving the head as described above will be described. Document data and the like are input to the microcomputer 8 via the Centro interface.
6, the data is temporarily stored in the RAM 88. Then, print data relating to character data and the like stored in the RAM 88 is sequentially extracted from the RAM 88, and a serial signal is supplied to the drive circuit 81 via the data line 83. At this time, the corresponding nozzle 41 to eject the corresponding ink droplet is determined based on the transferred print data, and the nozzle 41 is connected to the metal electrode 7 of the air chamber 13 located on both sides of the ink chamber 15 corresponding to the corresponding nozzle 41 to eject. The voltage V of the voltage line 84 is applied to the pattern 5 to be performed. Further, the other pattern 5 and the pattern 6 which is electrically connected to the metal electrode 7 of the ink chamber 15 are connected to the ground line 85.

When the normal print mode is selected via the panel 87, the fire clock signal is sent to the input terminal of each AND circuit 97 in the drive circuit 81 via the fire clock signal line 96 as described above. Is output. At the same time, the clock line 8
The serial signal (dot print signal) sent from the data line 83 in synchronization with the clock signal from
Are output to the AND circuit 97 from each output line 95a. In each AND circuit 97, an AND of the fire clock signal from the common fire clock signal line 96 and the serial signal from the output line 95a is obtained, and the fire signal is output to each driver 98 based on the result of the AND sum. Is output selectively. Each nozzle 41 is driven through such a fire signal, and ink droplets are ejected from each nozzle 41 to print a character or the like.

Here, the relationship between the serial signal and the fire signal will be described with reference to FIG. FIG.
5 is a timing chart showing a relationship between print data (dot print signal) based on a serial signal from a data line 83 and a fire signal output to each driver 98 in a normal print mode. According to this, after the transfer of one serial signal and before the transfer of the next serial signal, two fires are performed.
It can be seen that the signal is transmitted from the microcomputer 86 and output to each driver 98. That is, the transfer of two fire signals for one serial signal is printed as one set. Therefore, two dots are continuously formed for one print data.
It will be printed at the location. The printing result is shown in FIG. 11, and by controlling the timing of the fire signal and the moving speed of the carriage, control is performed so that the printing dot pitch formed in the main scanning direction is printed at half the pitch in the sub-scanning direction. I do.

On the other hand, when the high-speed print mode is selected via the panel 87, the cycle of the fire signal is the same as the normal print mode, and the transfer cycle of the serial signal is halved, as described above. , A fire clock signal is output to each AND circuit 97. At the same time, a serial signal (dot print signal) sent from the data line 83 in synchronization with the clock signal from the clock line 82
Are parallelized by the converter 95, and then each output line 9
5a is output to the AND circuit 97. In each AND circuit 97, an AND of the fire clock signal from the common fire clock signal line 96 and the serial signal from the output line 95a is obtained, and the fire signal is sent to each driver 98 based on the result of the AND sum. Output selectively. Each nozzle 41 is driven through such a fire signal, and ink droplets are ejected from each nozzle 41 to print a character or the like.

Here, the relationship between the serial signal and the fire signal will be described with reference to FIG. FIG.
This is a timing chart showing the relationship between print data (dot print signal) based on a serial signal from the data line 83 and a fire signal output to each tripper 98 in the high-speed print mode. According to this, after the transfer of one serial signal and before the transfer of the next serial signal, one fi
It can be seen that the re signal is transmitted from the microcomputer 88 according to the support of the panel 87 and output to each driver 98.
That is, printing of one fire signal is performed as one set for one print data. The cycle of the fire signal is the same as in the normal print mode. Note that the cycle of the serial signal in the high-speed print mode is half the cycle in the normal print mode. FIG. 13 shows the printing result. In the normal mode, the carriage moving speed was controlled so that the printing dot pitch in the main scanning direction was half the pitch in the sub-scanning direction. Since the speed is controlled to be twice that of the normal print mode, printing is performed so that the print dot pitch formed in the main scanning direction is the same as the pitch in the sub-scanning direction.

The embodiment of the ink jet recording apparatus according to the present invention has been described in detail. According to this, in the normal printing mode, the resolution in the main scanning direction is doubled in the sub-scanning direction. While two fire signals are transferred for data, in the high-speed print mode, one fire signal is used, and the carriage movement speed is increased to increase the resolution in the main scanning direction and the sub-scanning direction. As a result, printing without white spots can be performed without performing complicated processing. Further, in the normal printing mode, the resolution in the main scanning direction is set to be twice the resolution in the sub-scanning direction, so that the amount of ink droplets per dot can be reduced, which leads to a reduction in the amount of ink used.

It should be noted that the present invention is not limited to the above embodiment, and various changes can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the ink head using the piezoelectric ceramic plate has been described.

In this embodiment, the normal print mode is set to 1
Two fire signals are output for one print data,
In the normal print mode, three or more fire signals may be output for one print data. Further, in this embodiment,
Although one fire signal is output for one print data in the high-speed print mode, a smaller number of fire signals may be output for one print data in the high-speed print mode than in the normal print mode. .

In this embodiment, the cycle at which the serial signal is output in the high-speed print mode is half the cycle at which the serial signal is output in the normal print mode. The moving speed of the carriage was twice the moving speed of the carriage in the normal printing mode, but this is not a limitation. The cycle in which the serial signal in the high-speed printing mode is output is the same as the serial signal in the normal printing mode. when the 1 / N times the period to be a fast moving speed of the print mode of the carriage, usually it may be set to N times the moving speed of the print mode of the carriage.

In this embodiment, the amount of ink droplets is the same in the normal print mode and in the high-speed print mode. May be larger than the amount of the ink droplet. In this case, the difference in printing quality between the normal printing mode and the high-speed printing mode can be reduced, and the printing quality in the high-speed printing mode is better than in the above embodiment.

In this embodiment, there are two modes, that is, a normal printing mode and a high-speed printing mode. However, a plurality of modes having a large number of printing speeds may be used.

[0048]

As described above, according to the ink jet recording apparatus of the present invention, the first printing mode is switched by the printing mode switching means.
When the print mode is selected, the ink jet head and the recording medium are relatively moved at the first speed by the head scanning means, and ink droplets having different landing positions are ejected from each nozzle in response to one pulse signal. By jetting a plurality of characters, characters and the like are printed with high quality. Also, compared with the case where the second print mode is selected by the print mode selection means, unlike the above, when the first print mode corresponding to one of the pulse signal outputted from the pulse output means based on respective dot printing signals with the number of Lee ink droplets less is injected, to be printed from the previous SL first speed faster second speed
Can Ru. Moreover, as of claim 2, when the second print mode is selected, with each nozzle or leprosy ink droplets are ejected in accordance with the number of the drive signal is less than the first printing mode, While the inkjet head is scanned at a speed N times the first speed, the output period of the pulse signal is 1 / N.
Double and Ri'll be able to, which is, can be printed at high speed without missing white dots that make up the character or the like is generated.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a piezoelectric ceramic plate and a cover plate constituting a head of an ink jet recording apparatus according to one embodiment of the present invention.

FIG. 2 is a sectional perspective view showing a nozzle plate constituting a head of the ink jet recording apparatus according to one embodiment of the present invention.

FIG. 3 is a perspective view showing a piezoelectric ceramic plate constituting a head of the ink jet recording apparatus according to one embodiment of the present invention.

FIG. 4 is a perspective view showing a piezoelectric ceramic plate and a manifold member constituting a head of the ink jet recording apparatus according to one embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a part of a head of an ink jet recording apparatus according to one embodiment of the present invention.

FIG. 6 is an explanatory diagram showing the operation of the head of the ink jet recording apparatus according to one embodiment of the present invention.

FIG. 7 is a partial perspective view of an ink jet recording apparatus according to one embodiment of the present invention.

FIG. 8 is a block diagram showing a control device of the ink jet recording apparatus according to one embodiment of the present invention.

FIG. 9 is a block diagram showing a driving circuit of the inkjet recording apparatus according to one embodiment of the present invention.

FIG. 10 is a timing chart showing a relationship between a serial signal from a data line and a fire signal output to a driver in a normal print mode of the inkjet recording apparatus according to one embodiment of the present invention.

FIG. 11 is an explanatory diagram showing a printing mode in a normal printing mode of the inkjet recording apparatus according to one embodiment of the present invention.

FIG. 12 is a timing chart showing a relationship between a serial signal from a data line and a fire signal output to a driver in a high-speed printing mode of the inkjet recording apparatus according to one embodiment of the present invention.

FIG. 13 is an explanatory diagram showing a printing mode in a high-speed printing mode of the inkjet recording apparatus according to one embodiment of the present invention.

FIG. 14 is an explanatory diagram showing a printing mode in a normal mode of a conventional inkjet recording apparatus.

FIG. 15 is an explanatory diagram showing a printing mode in a high-speed printing mode of a conventional inkjet recording apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric ink jet 2 Piezoelectric ceramic plate 3 Cover plate 4 Nozzle plate 18 Manifold member 41 Nozzle 66 Carriage 70 Carriage motor 81 Drive circuit 82 Clock line 83 Data line 86 Microcomputer 87 Panel

Claims (3)

(57) [Claims] An ink jet head having a plurality of nozzles for ejecting ink droplets from each nozzle; a pulse signal output means for outputting a pulse signal based on each dot print signal in print data including a plurality of dot print signals; A plurality of inks having different landing positions of ink droplets corresponding to one pulse signal output from the pulse signal output means;
A first print mode for outputting a plurality of drive signals for ejecting droplets, and a second print mode for outputting a drive signal for ejecting a smaller number of ink droplets than the number of drive signals in the first print mode in response to one pulse signal Print mode switching means for selecting a first print mode by the print mode switching means, and ejecting a plurality of ink droplets from each of the nozzles based on the plurality of drive signals. When the second print mode is selected, drive means for ejecting ink droplets from each nozzle based on a smaller number of drive signals than in the first print mode, and the first print mode is selected by the print mode switching means. In this case, the ink jet head and the recording medium are relatively moved at the first speed, and the print mode switching means is used to move the ink jet head and the recording medium to the second speed.
An ink jet recording apparatus, comprising: a head scanning means for relatively moving an ink jet head and a recording medium at a second speed higher than the first speed when a print mode is selected. 2. The head according to claim 2, wherein the pulse signal output means outputs an output cycle of the pulse signal in the second print mode at 1 / N times an output cycle of the pulse signal in the first print mode. 2. The ink jet recording apparatus according to claim 1, wherein the scanning unit sets the second speed to a speed N times the first speed. 3. The ink jet recording apparatus according to claim 1, wherein the amount of ink droplets ejected in said second print mode is larger than the amount of ink droplets in said first print mode.