CN107415469A - inkjet recording device - Google Patents

Abstract

A kind of ink-jet recording apparatus that can suppress lettering omission is provided, for using pigment ink print image, wherein, average particle size during laser diffraction formula particle size distribution measurement is measured is 0.4 μm~6.5 μm, the difference of particle size when the average particle size and 50% accumulated value is in the range of ± 5%, less than 2 times of particle size when particle size during 90% accumulated value is 50% accumulated value.The ink-jet recording apparatus includes：Balancing gate pit, nozzle plate, ink box, ink supply department, ink feed lines, discharge unit, ink recovery path and circulation portions, the nozzle plate has a diameter of 20 μm~40 μm of nozzle, the nozzle has the size that the ratio of the diameter of the particle size and the nozzle during 50% accumulated value is 0.01~0.325, the circulation portions include configuring the pump on circulating path and circulate the pigment ink in circulating path, and circulating path includes the ink box, ink feed lines, ink recovery path, ink supply department, balancing gate pit and discharge unit.

Description

inkjet recording device

This application is a divisional application of a patent application with an application date of February 26, 2014, an application number of 201410067431.X, and an invention title of "Inkjet Recording Device and Recording Method", the entire contents of which are hereby incorporated by reference.

technical field

Embodiments of the present invention relate to an inkjet recording device and a recording method.

Background technique

Various types of ink jet heads such as piezoelectric type are known. As a piezoelectric inkjet head, for example, a so-called end jet type (End Shutter type) and a side jet type are known.

Sometimes dust or the like enters the ink chamber for supplying ink from the nozzles of the inkjet head. Also, sometimes air bubbles, foreign matter and coarse particles are mixed into the ink. Due to the above factors, the inkjet head has the worry of printing omissions.

In the bottom spray type inkjet head described above, the ink does not circulate. Therefore, much maintenance is performed on the above-mentioned bottom spray type inkjet head in order to eliminate air bubbles and the like to restore performance.

On the other hand, in the side jet type inkjet head, the ink circulates. Therefore, dust, air bubbles, and the like are discharged from the inside of the inkjet head, and nozzle clogging is suppressed.

Contents of the invention

The technical problem to be solved by the invention

Inkjet recording devices use various inks according to their uses. However, for example, if an ink with a large particle size of the pigment is used, there is a possibility that printing omission may occur even if no air bubbles etc. are mixed.

An object of the present invention is to provide an inkjet recording apparatus and a recording method capable of suppressing missing characters.

Technical solutions to technical problems

An inkjet recording device according to one embodiment includes an actuator, a nozzle plate, a supply unit, a discharge unit, and a circulation unit. The actuator has a pressure chamber containing ink, and changes the volume of the pressure chamber. The nozzle plate has a nozzle opening to the pressure chamber and having a diameter of 20 μm to 40 μm. The supply part supplies the ink to the pressure chamber. The discharge unit recovers the ink from the pressure chamber. The circulation section circulates the ink through the supply section, the pressure chamber, and the discharge section. The ink has an average particle size of 0.4 μm to 6.5 μm in laser diffraction particle size distribution measurement, the average particle size is approximately equal to the particle size at 50% cumulative value, and the particle size at 90% cumulative value is the 50% Twice or less the particle diameter at the time of cumulative value.

Description of drawings

FIG. 1 is a diagram schematically showing an inkjet printer according to an embodiment.

Fig. 2 is an exploded perspective view showing part of the inkjet head according to the embodiment.

3 is a cross-sectional view showing a part of the inkjet head according to the embodiment along the line F3-F3 in FIG. 2 .

4 is a table and a graph showing measurement results of a first example of ink used in the embodiment.

5 is a table and a graph showing measurement results of a second example of the ink used in the embodiment.

6 is a table and a graph showing measurement results of examples of inks not used in the embodiment.

Fig. 7 is a graph showing the relationship between ink particle length and printing omission in the embodiment.

FIG. 8 is a graph showing the relationship between ink particle size ratio and printing omission in the embodiment.

detailed description

Next, an embodiment will be described with reference to FIGS. 1 to 8 . In addition, although there are examples where one or more other expressions are added to each element that can have multiple expressions, this does not negate the addition of different expressions to elements that do not have other expressions, nor does it limit the addition of other expressions that are not illustrated.

FIG. 1 is a diagram schematically showing an inkjet printer 10 according to an embodiment. The inkjet printer 10 is an example of an inkjet recording device. As shown in Figure 1, the inkjet printer 10 has a first box 11, a first path 12, a second box 13, a first pump 14, a pneumatic valve 15, a second path 19, an inkjet head 21, a third path 22, The third tank 23 , the valve 24 , the fourth path 25 , the second pump 26 , and the control unit 29 .

The first tank 11 is an example of an ink tank. The first path 12, the second tank 13, and the second path 19 are an example of an ink supply path. The third path 22, the third tank 23, and the fourth path 25 are an example of an ink recovery path. The first pump 14, the pneumatic valve 15, the valve 24, the second pump 26, and the control unit 29 are an example of a circulation unit.

The first tank 11 contains ink. The first tank 11 is detachable from the inkjet printer 10 . When the ink contained in the first tank 11 is exhausted, the empty first tank 11 is replaced with a new first tank 11 by the user.

The first path 12 is connected to the first tank 11 . The first path 12 is, for example, a pipe through which ink passes. One end of the first path 12 is immersed in the ink contained in the first tank 11 .

The second tank 13 contains ink. The second tank 13 is connected to the other end of the first path 12 . The second tank 13 is connected to the first tank 11 through the first path 12 .

The second box 13 is equipped with a sensor 31 . The sensor 31 is, for example, a float sensor. The sensor 31 floats on the ink contained in the second tank 13 . The sensor 31 is turned on when the ink level contained in the second tank 13 is lower than a predetermined height, and is turned off when the ink level is higher than a predetermined height. That is, the sensor 31 detects the increase or decrease of the ink contained in the second tank 13 .

The first pump 14 is arranged in the middle of the first path 12 . The first pump 14 delivers the ink contained in the first tank 11 to the second tank 13 . The first pump 14 is operated or stopped by the control unit 29 .

An ink filter 33 is arranged in the middle of the first path 12 . The ink filter 33 removes dust and the like from the ink conveyed from the first tank 11 to the second tank 13 through the first path 12 .

A pneumatic valve 15 is connected to the second tank 13 . If the pneumatic valve 15 is open, the second tank 13 is open to the atmosphere. If the pneumatic valve 15 is closed, the second tank 13 is blocked from the atmosphere. The pneumatic valve 15 can be opened and closed by the control unit 29 .

Between the pneumatic valve 15 and the second tank 13 there is an overflow collector 34 , an air filter 35 and an overflow sensor 36 . The overflow collector 34 catches the rising ink. The air filter 35 removes dust from the air entering the second tank 13 through the pneumatic valve 15 . An overflow sensor 36 detects rising ink.

The second path 19 is connected to the second tank 13 . The second path 19 is, for example, a pipe through which ink passes. One end of the second path 19 is immersed in the ink contained in the second tank 13 . As described above, the first path 12 , the second tank 13 , and the second path 19 are connected to the first tank 11 .

The third path 22 is connected to the inkjet head 21 . The third path 22 is, for example, a pipe through which ink passes.

The third tank 23 contains ink. The third path 22 is connected to the third tank 23 . The third tank 23 is connected to the inkjet head 21 through the third path 22 .

FIG. 2 is an exploded perspective view showing part of the inkjet head 21 . FIG. 3 is a cross-sectional view showing a part of the inkjet head 21 along the line F3-F3 in FIG. 2 . As shown in FIG. 2 , the inkjet head 21 is a so-called side spray type shared mode shared wall type inkjet head. The inkjet head 21 is a device for discharging ink, and is mounted inside the inkjet printer 10 .

The inkjet head 21 has a base plate 41 , a nozzle plate 42 , a frame member 43 and a pair of actuators 44 . As shown in FIG. 3 , an ink chamber 46 for supplying ink is formed inside the inkjet head 21 .

And, as shown in the two-dot chain line of Fig. 3, various parts are installed on the inkjet head 21, such as the circuit board 47 for controlling the inkjet head 21, and for forming the inkjet head 21 and the second case 13. Manifold 48 for part of the path between.

As shown in FIG. 2 , the base plate 41 is made of ceramics such as alumina and formed into a rectangular plate shape. The base plate 41 has a flat mounting surface 51 . A plurality of supply holes 52 and a plurality of discharge holes 53 are provided on the mounting surface 51 .

The supply holes 52 are located at the central portion of the base plate 41 and are arranged along the length direction of the base plate 41 . As shown in FIG. 3 , the supply hole 52 communicates with the ink supply portion 48 a of the manifold 48 connected to the second path 19 .

The supply hole 52 is connected to the second path 19 through the ink supply portion 48a. The inkjet head 21 is connected to the second tank 13 through the second path 19 . That is, the inkjet head 21 is connected to the first tank 11 through the ink supply part 48 a of the multi-manifold 48 , the second path 19 , the second tank 13 , and the first path 12 .

As shown by the arrow in FIG. 3 , the ink in the second tank 13 passes through the second path 19 and the ink supply portion 48 a of the manifold 48 , and is supplied to the ink chamber 46 through the supply hole 52 . The first tank 11 , the first path 12 , the second tank 13 , the second path 19 , the ink supply portion 48 a of the manifold 48 , and the supply hole 52 are examples of the supply portion.

As shown in FIG. 2 , the discharge holes 53 are arranged in two rows so as to sandwich the supply holes 52 . As shown in FIG. 3 , the discharge hole 53 communicates with the ink discharge portion 48 b of the manifold 48 connected to the third path 22 . The discharge hole 53 , the ink discharge portion 48 b of the manifold 48 , the third path 22 , the third tank 23 , and the fourth path 25 are examples of the discharge portion.

The discharge hole 53 is connected to the third path 22 through the ink discharge portion 48b. As indicated by arrows in FIG. 3 , the ink in the ink chamber 46 passes through the ink discharge portion 48 b of the manifold 48 and the third path 22 , and is discharged from the discharge hole 53 to the third tank 23 .

As shown in FIG. 2 , the nozzle plate 42 is formed of, for example, a rectangular film made of polyimide. In addition, the nozzle plate 42 may be formed of other materials such as stainless steel. The nozzle plate 42 faces the mounting surface 51 of the base plate 41 .

A plurality of nozzles 55 are attached to the nozzle plate 42 . The number of nozzles in this embodiment is 636. The plurality of nozzles 55 are arranged in two rows along the length direction of the nozzle plate 42 . The nozzle 55 is opposed to a portion of the mounting surface 51 between the supply hole 52 and the discharge hole 53 . The nozzle 55 has a diameter of 24 μm. In addition, the diameter of the nozzle 55 is not limited to this, and it should just be 20 micrometers - 40 micrometers.

The frame member 43 is formed into a rectangular frame shape from a material such as nickel alloy. The frame member 43 is interposed between the mounting surface 51 of the base plate 41 and the nozzle plate 42 . The frame member 43 is bonded to the mounting surface 51 and the nozzle plate 42 respectively. That is, the nozzle plate 42 is attached to the base plate 41 via the frame member 43 .

As shown in FIG. 3 , the ink chamber 46 is surrounded by the base plate 41 , the nozzle plate 42 and the frame member 43 . The ink chamber 46 is formed between the base plate 41 and the nozzle plate 42 .

The pair of actuators 44 are each formed of two plate-shaped piezoelectric bodies made of, for example, lead zirconate titanate (PZT). Bonding the two piezoelectric bodies ensures that the polarization directions of the two piezoelectric bodies are opposite to each other in the thickness direction.

A pair of actuators 44 is bonded to the mounting surface 51 of the base plate 41 . The actuator 44 is bonded to the mounting surface 51 with, for example, a thermosetting epoxy resin adhesive. As shown in FIG. 2 , the actuator 44 corresponds to the nozzles 55 arranged in two rows, and is arranged in parallel in the ink chamber 46 . The cross section of the actuator 44 forms a trapezoidal shape. The top of the actuator 44 is bonded to the nozzle plate 42 .

As shown in FIG. 3 , the actuator 44 is provided with a plurality of pressure chambers 57 . The pressure chamber 57 is a groove formed in the actuator 44 . The actuator 44 has a plurality of side walls 58 forming a pressure chamber 57 . Each of the pressure chambers 57 extends in a direction intersecting the longitudinal direction of the actuator 44 and is arranged along the longitudinal direction of the actuator 44 .

The plurality of nozzles 55 of the nozzle plate 42 open to the plurality of pressure chambers 57 . As shown in FIG. 3 , the pressure chamber 57 is open to the ink chamber 46 . Accordingly, the ink passes through the pressure chamber 57 of the actuator 44 as indicated by the arrow in FIG. 3 . That is, the ink supplied from the supply hole 52 to the ink chamber 46 passes through the pressure chamber 57 of the actuator 44 and is discharged from the discharge hole 53 .

The pressure chambers 57 are each provided with electrodes 61 . The electrode 61 is formed of, for example, a nickel thin film. The electrode 61 covers the inner surface of the pressure chamber 57 .

As shown in FIG. 2 , a plurality of wiring patterns 62 are provided over the entire actuator 44 from the mounting surface 51 of the base plate 41 . The wiring pattern 62 is formed of, for example, a nickel thin film. The wiring patterns 62 each extend from the electrodes 61 formed at the pressure chamber 57 of the actuator 44 to one side end of the mounting surface 51 .

As shown in FIG. 3 , the circuit board 47 is a film carrier package (FCP), each having a thin film 65 and an IC, wherein the thin film 65 is made of resin, and has a plurality of wirings and has flexibility. The IC and the thin film 65 are described above. Multiple wiring connections. In addition, FCP is also known as tape-carrying package (TCP).

Film 65 is tape automated bonding (TAB). The IC is a part for applying a voltage to the electrode 61 . The IC is fixed to the film 65 with resin, for example.

The end of the thin film 65 is thermocompression-bonded to the wiring pattern 62 via an anisotropic conductive film (ACF) 66 . Thus, the plurality of wirings of the thin film 65 are electrically connected to the wiring pattern 62 . Since the thin film 65 is connected to the wiring pattern 62 , the IC is electrically connected to the electrode 61 through the wiring of the thin film 65 .

As shown in FIG. 1 , the valve 24 is arranged in the middle of the third path 22 . If the valve 24 is closed, the third path 22 is blocked and blocked. If the valve 24 is opened, the third path 22 is unblocked. The opening and closing of the valve 24 is controlled by the control unit 29 .

The fourth path 25 connects the third tank 23 and the first tank 11 . The fourth path 25 is, for example, a pipe through which ink passes. One end of the fourth path 25 is immersed in the ink contained in the third tank 23 .

As described above, the inkjet head 21 is connected to the first tank 11 through the ink discharge portion 48 b of the multi-manifold 48 , the third path 22 , the third tank 23 , and the fourth path 25 .

The second pump 26 is arranged in the middle of the fourth path 25 . The second pump 26 delivers the ink contained in the third tank 23 to the first tank 11 . The second pump 26 is operated or stopped by the control unit 29 .

The control unit 29 shown in FIG. 1 functions by various electronic components such as an integrated circuit or a memory. For example, the control unit 29 issues a printing command based on a user's operation. The printing command is, for example, information for image printing based on user operations. Although the control section 29 in FIG. 1 is connected only to the sensor 31, the control section 29 is connected to various components. The control unit 29 controls, for example, the first pump 14 , the pneumatic valve 15 , the inkjet head 21 , the valve 24 , and the second pump 26 .

The inkjet printer 10 and the controller 29 are switched among, for example, a standby state, a maintenance state, and a printing state. In the standby state, the control unit 29 opens the valve 24 to operate the second pump 26 . As the second pump 26 operates, the ink contained in the third tank 23 is sent to the first tank 11 . If the internal pressure of the third tank 23 decreases due to the ink being transported, the ink contained in the second tank 13 is transported to the third tank 23 by the inkjet head 21 . The ink passes through the pressure chamber 57 of the actuator 44 in the inkjet head 21 .

The water level of the ink contained in the second tank 13 drops due to the ink being transported. If the ink level of the second tank 13 is lower than a predetermined height, the sensor 31 is turned on. When the sensor 31 is turned on, the control unit 29 operates the first pump 14 . In other words, when the sensor 31 detects that the ink in the second tank 13 has decreased below a predetermined amount, the control unit 29 operates the first pump 14 . The ink contained in the first tank 11 is sent to the second tank 13 by the operation of the first pump 14 . When the ink level in the second tank 13 reaches a predetermined height due to ink delivery, the sensor 31 is cut off. When the sensor 31 is turned off, the control unit 29 stops the first pump 14 .

As described above, the first pump 14 , the pneumatic valve 15 , the valve 24 , the second pump 26 , and the control unit 29 circulate the ink in the first tank 11 in the inkjet printer 10 .

Next, the ink used in the inkjet printer 10 will be described. The ink used in the inkjet printer 10 (hereinafter simply referred to as "used ink") contains, for example, an aluminum pigment. In addition, the use of inks can also contain other types of pigments, not limited to aluminum pigments.

Fig. 4 is a table and a graph showing measurement results of a first example using ink. Fig. 5 is a table and a graph showing measurement results of a second example using ink. FIG. 6 is a table and a graph showing measurement results of examples of ink not used by the inkjet printer 10 (non-used ink). Measurements from FIG. 4 to FIG. 6 were performed by laser diffraction particle size distribution measurement. The "average particle diameter" described below is the average particle diameter obtained by laser diffraction particle size distribution measurement.

As shown in FIG. 4 , in the first example using the ink, the average particle diameter (mean value) of the pigment was 1.009 μm, and the particle diameter at the 50% cumulative value of the pigment was 0.995 μm. The particle diameter of the pigment at the 50% cumulative value means that when the powder is divided into two parts with a certain particle size, the diameter of the side with the larger diameter is equal to the diameter of the side with the smaller diameter.

As shown in FIG. 5 , in the second example using the ink, the average particle diameter (mean value) of the pigment was 0.596 μm, and the particle diameter at the 50% cumulative value of the pigment was 0.582 μm.

As shown in FIG. 6 , in the example where no ink is used, the average particle diameter (mean value) of the pigment is 1.600 μm, and the particle diameter at the 50% cumulative value of the pigment is 1.563 μm.

As described above, in the first and second examples using ink and the example not using ink, the average particle diameter of the pigment is approximately equal to the particle diameter at 50% cumulative value. In the first and second examples using the ink and the example not using the ink, the difference in the particle diameter at the 50% cumulative value of the pigment with respect to the average particle diameter of the pigment is within ±5%. In the first and second examples using the ink, the average particle diameter of the pigment is between 0.4 μm and 1.3 μm.

In the first example using the ink, the particle diameter (1.912 μm) at the 90% cumulative value of the pigment is twice or less than the particle diameter (0.995 μm) at the 50% cumulative value of the pigment. In the second example using the ink, the particle diameter (1.113 μm) at the 90% cumulative value of the pigment is twice or less than the particle diameter (0.582 μm) at the 50% cumulative value of the pigment. In an example not using ink, the particle diameter (2.792 μm) at the 90% cumulative value of the pigment is twice or less than the particle diameter (1.563 μm) at the 50% cumulative value of the pigment.

The standard deviation of the pigment of the first example using ink was 0.206, the standard deviation of the pigment of the second example using ink was 0.196, and the standard deviation of the pigment of the example not using ink was 0.174. That is, the standard deviation of the pigments in the first and second examples using ink and the example not using ink was 0.21 or less.

In the first and second examples using ink and the example not using ink, the particle diameter at 50% cumulative value of the pigment is between 0.01 and 0.325 times the diameter of the nozzle 55 . In other words, in the present embodiment, the particle diameters at the 50% cumulative value of the pigments of the first and second examples using the ink and the example not using the ink are between 0.24 μm and 7.8 μm.

The aluminum pigment is in the form of scales (approximately rectangular plates) and has a thickness, a grain width, and a grain length. In other words, the shape of the aluminum pigment is non-spherical. Thickness is the shortest dimension of the pigment particle. The grain width is the shortest dimension in the pigment grain in the direction crossing the thickness. The particle length is the longest dimension in the pigment particle in the direction crossing the thickness. In addition, in inks containing spherical pigments, the particle diameters measured from any angle are the same, and the average particle diameter is equal to the average particle length.

In the first and second examples using ink and the example not using ink, the thickness of the pigment is 20 nm to 100 nm, and the particle width is 0.5 μm to 3 μm. In the first and second examples using ink and the example not using ink, the average particle length was about 5 times the average particle diameter. That is, in the first example using the ink, the average particle length of the pigment is about 5 μm, in the second example using the ink, the average particle length of the pigment is about 3 μm, and in the example not using the ink, the average particle length of the pigment is The length is about 8 μm. In addition, the average particle length of the pigment used in the ink is not limited thereto, and may be 1 to 5 times the average particle diameter of the pigment.

Next, an example of an image forming method of the inkjet printer 10 will be described. First, the inkjet printer 10 and the control unit 29 enter the above-mentioned standby state. The description of the operations of the inkjet printer 10 and the control unit 29 in the standby state is as described above, and is omitted here.

In the standby state, the control unit 29 waits, for example, for an operation from a user. For example, when the control unit 29 issues a printing command according to a user's operation, the inkjet printer 10 passes through the maintenance state and enters the printing state. In the maintenance state, the control unit 29 cleans the nozzles 55 of the inkjet head 21 .

In the printing state described above, the printing medium P such as recording paper is arranged below the inkjet head 21 . The inkjet head 21 deforms the actuator 44 to the shared mode in accordance with a printing command from the control unit 29 .

The actuator 44 deforms through the shared mode, causing the volume of the pressure chamber 57 to increase and decrease. Accordingly, the ink contained in the pressure chamber 57 is decompressed and pressurized, and is discharged from the nozzle 55 . The ink remaining in the pressure chamber 57 without being discharged is returned to the first tank 11 through the discharge hole 53 .

The ejected ink adheres to the printing medium P. As shown in FIG. After the ink is discharged, the inkjet head 21 and the printing medium P move. An image is formed on the printing medium P by repeatedly ejecting ink according to a printing command by the inkjet head 21 .

After an image is formed on the printing medium P according to the printing command, the above-mentioned printing state ends. After the above-mentioned printing state is completed, the inkjet printer 10 and the control unit 29 switch to the above-mentioned standby state. As described above, the inkjet printer 10 forms images.

Fig. 7 is a graph showing the relationship between the particle length of the ink pigment and the printing omission. Table 1 shows various conditions of the ink pigments in the experiment of the profile of FIG. 7 . The experiment in FIG. 7 and Table 1 is an experiment in which printing omission was measured when various voltages were applied to the actuator 44, and an average value was obtained. The multiple voltages are a voltage (predetermined voltage) for ejecting 42 pl of ink, a voltage that differs from the predetermined voltage by ±2 V, and a voltage that differs from the predetermined voltage by ±1 V in five levels.

In FIG. 7 and Table 1, the 90% particle diameter, 50% particle diameter, and 10% particle diameter represent the particle diameters of the pigments at the 90% cumulative value, 50% cumulative value, and 10% cumulative value. The sizes of the ink pigments in Table 1 are measured by laser diffraction particle size distribution measurement.

In Table 1, ink number 6 is the first example of using the ink shown in FIG. 4 . Ink number 7 is the second example of using the ink shown in FIG. 5 . Ink number 8 is an example of the non-used ink shown in FIG. 6 .

Table 1

As shown in Table 1, in the experiment of FIG. 7 and Table 1, the ratio of the 90% particle diameter to the 50% particle diameter of ink No. 1 to ink No. 10 was 2.0 or less. In addition, the average particle diameter of ink No. 1 to ink No. 10 is substantially equal to the 50% particle diameter. As shown in the approximate curve L of FIG. 7, if the average particle length exceeds 6.5 μm (ie, if the average particle diameter exceeds 1.3 μm), the average number of missing prints increases rapidly.

As mentioned above, when the average particle diameter of the pigment used in the ink is 1.3 μm or less, the average particle diameter is approximately equal to the 50% particle diameter, and the 90% particle diameter is less than twice the 50% particle diameter, the average printing omission number decreased.

In addition, in the case of using an ink containing an aluminum pigment, it is difficult to pulverize aluminum to a size of 0.4 μm or less. Therefore, the average particle size of the ink pigment with reduced average number of missing prints is 0.4 μm to 1.3 μm.

Consider the case where the pigment of the ink used is spherical. The factor affecting print dropout is the largest dimension in the pigment, which in aluminum pigments is the particle length. As mentioned above, the particle length in aluminum pigments is about 5 times the particle diameter. On the other hand, spherical pigments have a particle length equal to the particle diameter. Therefore, in inks containing spherical pigments, the average particle diameter of the ink pigments in which the average number of printing omissions is reduced is 6.5 μm or less.

Fig. 8 is a distribution diagram showing the relationship between the particle size ratio of ink pigments and printing omission. Table 2 shows various conditions of the ink pigments in the experiment of the profile of FIG. 8 . The experiment in FIG. 8 and Table 2 is an experiment in which printing omission was measured when various voltages were applied to the actuator 44 and an average value was obtained. The above-mentioned multiple voltages are a voltage (predetermined voltage) for ejecting 42 pl of ink, a voltage that differs from the predetermined voltage by ±2 V, and a voltage that differs from the predetermined voltage by ±1 V in five levels.

In FIG. 8 and Table 2, the 90% particle diameter, 50% particle diameter, and 10% particle diameter represent the particle diameters of the pigments at the 90% cumulative value, 50% cumulative value, and 10% cumulative value. The sizes of the ink pigments in Table 2 are measured by laser diffraction distribution measurement.

In Table 2, ink number D is the second example of using the ink shown in FIG. 5 .

Table 2

As shown in Table 2, in the experiment of FIG. 8 and Table 2, the average particle diameter of the inks of ink numbers A to H was 1.3 μm or less. In addition, the average particle diameter of the inks of ink number A to ink number H is substantially equal to the 50% particle diameter. As shown in FIG. 8, when the ratio of the 90% particle size to the 50% particle size exceeds 2.0, the average number of missing characters increases. As shown in Figure 8 and Table 2, when the average particle size of the pigment used in the ink is 1.3 μm or less, the average particle size is approximately equal to the 50% particle size, and the 90% particle size is less than twice the 50% particle size , the average number of printing omissions is reduced. In FIG. 8 , the number of print omissions in a good range is surrounded by a two-dot chain line.

According to the inkjet printer 10 of this embodiment, it is possible to discharge ink having a large pigment particle size. In other words, the inkjet printer 10 of the present embodiment can use ink containing an average particle diameter of 0.4 μm to 1.3 μm while suppressing printing omissions. In the case where the ink pigment is spherical, the average particle diameter at which printing omission is suppressed is 0.4 μm to 6.5 μm.

In inks containing aluminum pigments, the larger the particle size of the pigments, the better the gloss of the printed image. Not limited to aluminum pigments, but all pigments with metallic luster.

If the particle diameter of the pigment is large, there is a possibility that printing omission may occur even if air bubbles and the like are not mixed. However, as shown in this embodiment, by using an ink containing a pigment whose average particle diameter is 1.3 μm or less, the average particle diameter is approximately equal to the 50% particle diameter, and the 90% particle diameter is twice or less than the 50% particle diameter, it is possible to Omission of printing is suppressed.

In addition, the inkjet printer 10 of this embodiment can also use ink with a smaller particle size. Accordingly, the inkjet printer 10 can handle various inks.

According to at least one inkjet recording device and recording method described above, the average particle diameter in the circulation type inkjet recording device using laser diffraction particle size distribution measurement is 0.4 μm to 6.5 μm, the average particle diameter and 50% The particle diameters at the cumulative value are approximately equal, and the particle diameter at the 90% cumulative value is not more than twice the particle diameter at the above-mentioned 50% cumulative value. Thereby, it is possible to use ink containing a large-diameter pigment while suppressing printing omissions.

Although some embodiments of the present invention have been described, these embodiments are merely illustrative of the present invention and are not intended to limit the scope of the present invention. The various new embodiments described herein can be implemented in various other ways, and various omissions, substitutions and changes can be made without departing from the spirit of the present invention. The appended claims and their equivalents cover such embodiments and modifications as fall within the scope and spirit of the invention.

Symbol Description

10 inkjet printer, 11 first box, 12 first path, 13 second box

14 first pump, 15 pneumatic valve, 19 second path, 21 inkjet head

22 third path, 23 third box, 24 valve, 25 fourth path

26 second pump, 29 control section, 42 nozzle plate, 44 actuator

52 supply hole, 53 discharge hole, 55 nozzle, 57 pressure chamber

Claims (10)

1. a kind of ink-jet recording apparatus, for using the pigment ink print image comprising pigment, wherein, pass through laser diffraction formula The average particle size of the pigment measured by particle size distribution measurement is 0.4 μm~6.5 μm, the average particle size and The difference of the particle size of pigment during 50% accumulated value is in the range of ± 5%, pigment during 90% accumulated value Less than 2 times of particle size of particle size when being 50% accumulated value, the ink-jet recording apparatus includes：

Balancing gate pit, accommodate the pigment ink and change the volume of balancing gate pit to spray the pigment ink；

Nozzle plate, having to balancing gate pit's opening and a diameter of 20 μm~40 μm of nozzle, the nozzle has described 50% The ratio of the diameter of particle size and the nozzle during accumulated value is 0.01~0.325 size；

Ink box, accommodate the pigment ink；

Ink supply department, the pigment ink is supplied to the balancing gate pit；

Ink feed lines, including the end being connected with the ink box and the end being connected with the ink supply department；

Discharge unit, the pigment ink is reclaimed from the balancing gate pit；

Ink reclaims path, including the end being connected with the ink box and the end being connected with the discharge unit；And

Circulation portions, including configure the pump on circulating path and circulate the pigment ink in the circulating path, the circulation Path includes the ink box, the ink feed lines, ink recovery path, the ink supply department, the pressure Room and the discharge unit.

2. ink-jet recording apparatus according to claim 1, wherein,

The pump configuration is on ink recovery path.

3. ink-jet recording apparatus according to claim 1, wherein,

The standard deviation of the particle size distribution of the pigment is less than 0.21 μm.

4. a kind of ink-jet recording apparatus, for using the pigment ink print image comprising pigment, wherein, pass through laser diffraction formula The average particle size of pigment measured by particle size distribution measurement is 0.4 μm~6.5 μm, and the average particle size and 50% tires out The difference of the particle size of pigment during product value is in the range of ± 5%, the standard of the particle size distribution of the pigment Deviation is less than 0.21 μm, and the ink-jet recording apparatus includes：

Balancing gate pit, accommodate the pigment ink and change the volume of balancing gate pit to spray the pigment ink；

Nozzle plate, having to balancing gate pit's opening and a diameter of 20 μm~40 μm of nozzle, the nozzle has described 50% The ratio of the diameter of particle size and the nozzle during accumulated value is 0.01~0.325 size；

Ink box, accommodate the pigment ink；

Ink supply department, the pigment ink is supplied to the balancing gate pit；

Ink feed lines, including the end being connected with the ink box and the end being connected with the ink supply department；

Discharge unit, the pigment ink is reclaimed from the balancing gate pit；

Ink reclaims path, including the end being connected with the ink box and the end being connected with the discharge unit；And

Circulation portions, including configure the pump on circulating path and circulate the pigment ink in the circulating path, the circulation Path includes the ink box, the ink feed lines, ink recovery path, the ink supply department, the pressure Room and the discharge unit.

5. ink-jet recording apparatus according to claim 4, wherein,

The pump configuration is on ink recovery path.

6. a kind of ink-jet recording apparatus, for being formed aspherical pigment ink print image using wherein pigment, wherein, The average particle size of the pigment in laser diffraction formula particle size distribution measurement is 0.4 μm~1.3 μm, the averaged particles chi The difference of the particle size of pigment during very little and 50% accumulated value is described during 90% accumulated value in the range of ± 5% Less than 2 times of particle size when the particle size of pigment is 50% accumulated value, the ink-jet recording apparatus includes：

Balancing gate pit, accommodate the pigment ink and change the volume of balancing gate pit to spray the pigment ink；

Nozzle plate, having to balancing gate pit's opening and a diameter of 20 μm~40 μm of nozzle, the nozzle has described 50% The ratio of the diameter of particle size and the nozzle during accumulated value is 0.01~0.325 size；

Ink box, accommodate the pigment ink；

Ink supply department, the pigment ink is supplied to the balancing gate pit；

Ink feed lines, including the end being connected with the ink box and the end being connected with the ink supply department；

Discharge unit, the pigment ink is reclaimed from the balancing gate pit；

Ink reclaims path, including the end being connected with the ink box and the end being connected with the discharge unit；And

Circulation portions, including configure the pump on circulating path and circulate the pigment ink in the circulating path, the circulation Path includes the ink box, the ink feed lines, ink recovery path, the ink supply department, the pressure Room and the discharge unit.

7. ink-jet recording apparatus according to claim 6, wherein,

The pump configuration is on ink recovery path.

8. ink-jet recording apparatus according to claim 6, it is characterised in that：

The pigment shape of the pigment ink is flakey.

9. ink-jet recording apparatus according to claim 8, it is characterised in that：

The pigment shape is that thickness is 20nm~100nm, and width is 0.5 μm~3 μm, and length is the averaged particles 1~5 times of size.

10. ink-jet recording apparatus according to claim 6, it is characterised in that：

The standard deviation of the particle size distribution of the pigment is less than 0.21 μm.