JP3804859B2 - Liquid ejector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid ejecting apparatus that ejects liquid droplets from nozzle openings, and more particularly, to a liquid ejecting apparatus that ejects liquid drops from a plurality of nozzle openings.
[0002]
[Prior art]
An ink jet recording apparatus (a type of liquid ejecting apparatus) such as an ink jet printer or an ink jet plotter moves a recording head (head member) along the main scanning direction and also transfers a recording paper (a type of liquid ejected medium) An image (including characters and the like) is recorded on the recording paper by moving along the scanning direction and ejecting ink droplets from the nozzle openings of the recording head in conjunction with the movement. The ink droplets are ejected, for example, by expanding and contracting a pressure generating chamber that communicates with the nozzle opening.
[0003]
The expansion / contraction of the pressure generating chamber is performed using, for example, deformation of the piezoelectric vibrator. In such a recording head, the piezoelectric vibrator is deformed in accordance with the supplied driving pulse, thereby changing the volume of the pressure chamber, and this volume change causes a pressure fluctuation in the ink in the pressure chamber, and the nozzle opening. Ink droplets are ejected.
[0004]
In such a recording apparatus, a drive signal formed by connecting a plurality of pulse waveforms in series is generated. On the other hand, print data including gradation information is transmitted to the recording head. Then, based on the transmitted print data, only a necessary pulse waveform is selected from the drive signal and supplied to the piezoelectric vibrator. Thereby, the amount of ink droplets ejected from the nozzle openings is changed according to the gradation information.
[0005]
On the other hand, a recording head for color printing is provided with a plurality of rows of nozzle openings for discharging a plurality of colors of ink in parallel. Desired color recording is realized by discharging ink of each color as appropriate. The multiple color inks are, for example, black ink, cyan ink, magenta ink, and yellow ink.
[0006]
[Problems to be solved by the invention]
Generally, a plurality of types of recording paper can be used in an ink jet recording apparatus. The thickness of these recording sheets may not be uniform. There is also a recording apparatus that can change the distance from the recording head to the recording paper. Further, the distance from the recording head to the recording paper varies due to the assembly error of the recording apparatus.
[0007]
The inventors of the present invention have found that when the distance from the recording head to the recording paper is changed, the color tone of color printing can change.
[0008]
For example, in a recording head for color printing, a row of nozzle openings that discharge cyan ink (C), a row of nozzle openings that discharge magenta ink (M), and a nozzle opening that discharges yellow ink (Y). Consider a case in which columns are provided in parallel in this order, and printing is performed in the order of cyan ink (C), magenta ink (M), and yellow ink (Y) while the recording head is moving. In this case, while the recording head is moving, recording is performed in the order of yellow ink (Y), magenta ink (M), and cyan ink (C).
[0009]
Here, ink of each color is ejected onto the recording paper from each nozzle opening, but if the distance between each nozzle opening and the recording paper is not sufficiently large, so-called main droplets and satellite droplets are sufficient. They will land without being separated and overlapping.
[0010]
The inventor of the present invention has found that the color tone can change due to overlapping of ink droplets of the same color to be separated. The inventor has analyzed this phenomenon as follows.
[0011]
The cyan ink (C) and the magenta ink (M) have their OD values increased at the same ratio by overlapping the ink droplets. Furthermore, a proportional relationship is established between the number of superimposed ink droplets and the increased OD value.
[0012]
However, in the yellow ink (Y), a proportional relationship is not established between the number of superimposed ink droplets and the increased OD value, and the OD value increases quickly. As a result, in the yellow ink (Y), the increase (elongation) of the OD value due to the overlapping of the ink droplets is small compared to the other ink colors. This phenomenon is considered to be caused by the fact that the yellow color material has the weakest color, and the color material ratio in the ink is the highest in yellow.
[0013]
As described above, there is a difference in characteristics between ink colors when ink droplets overlap. This difference appears as a change in color tone when the distance between each nozzle opening and the recording paper is not sufficiently large.
[0014]
A specific example is shown in FIG. In the case shown in FIG. 12, when the distance (PG: Paper Gap) between each nozzle opening and the recording paper is 1.06 mm or less, the main droplet and the satellite droplet overlap each other, and the hue difference ΔE increases. .
[0015]
The present invention has been made in consideration of such points, and adjusts the relative proportion of the amount of each liquid ejected from each nozzle opening in accordance with the distance between each nozzle opening and the recording paper. An object of the present invention is to provide, for example, an ink jet recording apparatus that can adjust the color tone, and in general, a liquid ejecting apparatus.
[0016]
[Means for Solving the Problems]
The present invention relates to a head member having a plurality of nozzle openings, a plurality of pressure varying means for ejecting the liquid by varying the pressure of the liquid in each nozzle opening portion, and an ejection medium holding unit for retaining a liquid ejection medium And a moving mechanism for moving the head member relatively in parallel with the liquid ejection medium so that the plurality of nozzle openings of the head member pass through the position facing the liquid ejection medium, and each pressure variation means A drive signal output means for outputting a drive signal to the head, a control main body for driving each pressure varying means based on the drive signal during the movement of the head member to eject liquid from each nozzle opening, and a plurality of head members A distance identification unit that identifies the distance between the movement trajectory of the nozzle opening and the liquid ejection medium, and a relative amount of each liquid ejected from each nozzle opening based on the distance identified by the distance identification unit Ratio so as to output a driving signal such that the desired ratio corresponding to the distance, which is a liquid ejecting apparatus comprising: the distance adjusting unit for controlling the drive signal output means.
[0017]
According to the present invention, based on the distance identified by the distance identifying unit, the relative ratio of the amount of each liquid ejected from each nozzle opening can be adjusted to a desired ratio corresponding to the distance. For this reason, it is possible to suitably compensate for a change in landing characteristics caused by, for example, an overlap at the time of landing between the main droplet and the satellite droplet of each liquid.
[0018]
For example, each nozzle opening is divided into a plurality of nozzle opening groups to which liquids of different colors are supplied, and the drive signal output means outputs a drive signal for each pressure fluctuation means group corresponding to each nozzle opening group. It is designed to output. In this case, the relative proportion of the amount of each liquid ejected from each nozzle opening group is adjusted to a desired proportion corresponding to the distance, so that the main droplets and satellite droplets of each liquid overlap when landing. The resulting change in color tone can be suitably compensated.
[0019]
More specifically, for example, the plurality of nozzle openings are at least 3 or more, and the different color liquids are a cyan liquid, a magenta liquid, and a yellow liquid.
[0020]
Preferably, the distance between the movement trajectory of the plurality of nozzle openings of the head member and the liquid ejection medium is a support for supporting the liquid ejection medium of the plurality of nozzle openings of the head member and the ejection medium holding portion. It is obtained from the distance to the surface and the thickness of the liquid ejection medium. For example, the distance can be obtained by subtracting the thickness of the liquid ejected medium from the distance between the movement track of the nozzle opening and the support surface.
[0021]
Alternatively, a sensor that detects the distance between the movement trajectory of the plurality of nozzle openings of the head member and the liquid ejection medium may be provided. Alternatively, it is possible to provide a PG adjustment mechanism that can change the distance between the movement trajectory of the plurality of nozzle openings of the head member and the liquid ejection medium and can acquire information on the distance.
[0022]
Preferably, the distance adjustment unit is connected to a liquid ratio storage unit that stores a desired ratio of the amount of each liquid to be ejected from each nozzle opening in association with the distance identified by the distance identification unit. Yes.
[0023]
Specifically, for example, the liquid ratio storage unit indicates a desired ratio of the amount of each liquid to be ejected from each nozzle opening, and the distance identified by the distance identification unit is separated from the main droplet and the satellite droplet. Based on whether or not the distance is sufficient to be recorded, at least binarized and stored.
[0024]
Alternatively, preferably, the liquid ratio storage unit stores a desired ratio of the amount of each liquid to be ejected from each nozzle opening as table data corresponding to the distance identified by the distance identification unit.
[0025]
In addition, it is preferable that the said distance adjustment part makes the said drive signal output means increase / decrease the amplitude of the said drive signal. Alternatively, it is preferable that the distance adjustment unit is configured to increase or decrease the pulse width of the drive signal by using the drive signal output means.
[0026]
The present invention also provides a head member having a plurality of nozzle openings, a plurality of pressure fluctuation means for ejecting the liquid by varying the pressure of the liquid in each nozzle opening portion, and an ejection medium that holds the liquid ejection medium. A holding unit and a moving mechanism that moves the head member relatively in parallel with the liquid ejection medium so that the plurality of nozzle openings of the head member pass through the position facing the liquid ejection medium. A device for controlling the liquid ejecting apparatus,
Drive signal output means for outputting a drive signal to each pressure fluctuation means;
A control main body for ejecting liquid from each nozzle opening by driving each pressure variation means based on the drive signal during movement of the head member;
A distance identifying unit that identifies the distance between the movement trajectory of the plurality of nozzle openings of the head member and the liquid ejection medium;
Based on the distance identified by the distance identifying unit, the drive signal is output so that the relative ratio of the amount of each liquid ejected from each nozzle opening is a desired ratio corresponding to the distance. A distance adjusting unit for controlling the output means;
A control device comprising:
[0027]
The control device or each element means of the control device can be realized by a computer system.
[0028]
Further, a program for causing a computer system to implement each device or each means and a computer-readable recording medium recording the program are also subject to protection in this case.
[0029]
Here, the recording medium includes not only a floppy disk or the like that can be recognized as a single unit, but also a network that propagates various signals.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0031]
As shown in FIG. 1, an ink jet recording apparatus (an example of a liquid ejecting apparatus) according to the present embodiment is an ink jet printer 1, and includes a cartridge holder portion 3 capable of holding a black ink cartridge 2a and a color ink cartridge 2b. A carriage 5 having a recording head 4 (an example of a head member) is provided. The carriage 5 is reciprocated along the main scanning direction by a head scanning mechanism (an example of a moving mechanism).
[0032]
The head scanning mechanism includes a guide member 6 installed in the left-right direction of the housing, a pulse motor 7 provided on one side of the housing, a drive pulley 8 connected to the rotating shaft of the pulse motor 7 and driven to rotate. An idler pulley 9 attached to the other side of the housing, a timing belt 10 spanned between the drive pulley 8 and the idler pulley 9 and coupled to the carriage 5, and a controller for controlling the rotation of the pulse motor 7. 11 (see FIG. 6). Accordingly, by operating the pulse motor 7, the carriage 5, that is, the recording head 4 can be reciprocated in the main scanning direction which is the width direction of the recording paper 12.
[0033]
A PG adjustment lever 19 that can switch the position of the guide member 6 in a plurality of stages in the vertical direction is attached to the guide member 6. “PG” means the distance between each nozzle opening and the recording paper, and the user can select a suitable PG according to the thickness of the recording paper to be used and the degree of deformation of the recording paper.
[0034]
The printer 1 also includes a paper feeding mechanism (an example of an ejected medium holding unit) that feeds a recording medium (an example of a liquid ejected medium) such as the recording paper 12 in the paper feeding direction (sub-scanning direction). The paper feed mechanism is composed of a paper feed motor 13 and a paper feed roller 14. A recording medium such as the recording paper 12 is sequentially sent out in conjunction with the recording operation.
[0035]
The head scanning mechanism and the paper feed mechanism of the present embodiment are configured to be compatible with large-sized recording paper 12 of about B0 size. Further, the printer 1 according to the present embodiment is configured to execute a recording operation (perform unidirectional recording) when the recording head 4 moves forward.
[0036]
A home position and a standby position of the recording head 4 (carriage 5) are set in an end area within the movement range of the carriage 5 and outside the recording area. As shown in FIG. 2A, the home position is set at one end (right side in the drawing) of the head movement range in which the recording head 4 can move. Further, the standby position is set substantially adjacent to the home position on the recording area side.
[0037]
The present invention can also be applied to a printer configured to execute a recording operation (perform bi-directional recording) both when the recording head 4 moves forward and backward. In such a printer, as shown in FIG. 2B, in addition to the first standby position WP1 substantially adjacent to the home position, a second standby position WP2 is provided at the end opposite to the home position. Can be.
[0038]
The home position is a place where the recording head 4 moves and stays when recording is not performed when the power is turned off or for a long time. When the recording head 4 is located at the home position, as shown in FIG. 3D, the cap member 15 of the capping mechanism contacts the nozzle plate 16 (see FIG. 4) to seal the nozzle opening 17 (see FIG. 4). Stop. The cap member 15 is a member obtained by molding an elastic member such as rubber into a substantially square tray shape whose upper surface is open, and a moisturizing material such as felt is attached inside. By sealing the recording head 4 with the cap member 15, the inside of the cap is kept at high humidity, and evaporation of the ink solvent from the nozzle openings 17 is alleviated.
[0039]
The standby position is a position that becomes a starting point when scanning the recording head 4. That is, the recording head 4 normally stands by at this standby position, is scanned from the standby position to the recording area side during the recording operation, and returns to the standby position when the recording operation is completed.
[0040]
In the case of a printer that performs bi-directional recording, referring to FIG. 2B, the recording head 4 is scanned from the standby state at the first standby position WP1 to the second standby position WP2 side to move forward. Record the hour. When this recording operation ends, the recording apparatus waits at the second standby position WP2. Next, the recording head 4 is scanned from the standby state at the second standby position WP2 to the first standby position WP1 side to perform a recording operation at the time of backward movement. When this recording operation ends, the recording apparatus waits at the first standby position WP1. Thereafter, the recording operation during the forward movement and the recording operation during the backward movement are repeatedly performed alternately.
[0041]
The standby position is provided with an ink receiving member for collecting ink discharged by the recording head 4 by a flushing operation (a kind of maintenance operation). In the present embodiment, the cap member 15 also serves as an ink receiving member. That is, as shown in FIG. 3A, the cap member 15 is usually disposed at a position below the standby position of the recording head 4 (position slightly spaced below the nozzle plate 16). Then, as the recording head 4 moves to the home position, as shown in FIG. 3D, the recording head 4 moves obliquely upward (home position side and nozzle plate 16 side) to seal the nozzle opening 17. .
[0042]
In the case of a printer that performs bidirectional recording, as shown in FIG. 2B, an ink receiving member 18 is also disposed at the second standby position WP2. The ink receiving member 18 can be constituted by, for example, a box-like flushing box having an opening surface facing the recording head 4.
[0043]
Further, in the present embodiment, an acceleration area is set between the standby position and the recording area. The acceleration area is an area for accelerating the scanning speed of the recording head 4 to a predetermined speed.
[0044]
Next, the recording head 4 will be described. As shown in FIG. 4, the recording head 4 includes a comb-like piezoelectric vibrator 21 inserted into a storage chamber 72 of a box-like case 71 made of plastic, for example, through one opening, and a comb-like tip portion. 21a faces the other opening. The flow path unit 74 is joined to the surface (lower surface) of the case 71 on the other opening side, and the comb-shaped tip portion 21 a is in contact with and fixed to a predetermined portion of the flow path unit 74.
[0045]
The piezoelectric vibrator 21 is configured by cutting a plate-like vibrator plate in which common internal electrodes 21c and individual internal electrodes 21d are alternately stacked with a piezoelectric body 21b interposed therebetween, and cutting it into a comb tooth shape corresponding to the dot formation density. It is. Then, by applying a potential difference between the common internal electrode 21c and the individual internal electrode 21d, each piezoelectric vibrator 21 expands and contracts in the vibrator longitudinal direction orthogonal to the stacking direction.
[0046]
The channel unit 74 is configured by laminating the nozzle plate 16 and the elastic plate 77 on both sides with the channel forming plate 75 interposed therebetween.
[0047]
The flow path forming plate 75 communicates with a plurality of nozzle openings 17 provided in the nozzle plate 16 and is arranged at least at one end of each pressure generating chamber 22 and a plurality of pressure generating chambers 22 arranged with a pressure generating chamber partition therebetween. This is a plate material on which a plurality of ink supply portions 82 communicating with each other and an elongated common ink chamber 83 communicating with all the ink supply portions 82 are formed. For example, an elongated common ink chamber 83 is formed by etching a silicon wafer, and the pressure generation chambers 22 are formed in accordance with the pitch of the nozzle openings 17 along the longitudinal direction of the common ink chamber 83. A groove-shaped ink supply part 82 may be formed between the ink 22 and the common ink chamber 83. In this case, the ink supply unit 82 is connected to one end of the pressure generating chamber 22, and the nozzle opening 17 is disposed in the vicinity of the end opposite to the ink supply unit 82. The common ink chamber 83 is a chamber for supplying the ink stored in the ink cartridge to the pressure generating chamber 22, and an ink supply pipe 84 is communicated with substantially the center in the longitudinal direction.
[0048]
The elastic plate 77 is laminated on the surface of the flow path forming plate 75 opposite to the nozzle plate 16, and a double structure in which a polymer film such as PPS is laminated on the lower surface side of the stainless steel plate 87 as an elastic film 88. It is. Then, an island portion 89 for abutting and fixing the piezoelectric vibrator 21 is formed by etching the portion of the stainless plate 87 corresponding to the pressure generating chamber 22.
[0049]
In the recording head 4 having the above configuration, by extending the piezoelectric vibrator 21 in the longitudinal direction of the vibrator, the island portion 89 is pressed toward the nozzle plate 16 side, and the elastic film 88 around the island portion 89 is deformed. The pressure generation chamber 22 contracts. When the piezoelectric vibrator 21 is contracted in the longitudinal direction from the contracted state of the pressure generating chamber 22, the pressure generating chamber 22 expands due to the elasticity of the elastic film 88. When the pressure generating chamber 22 is once expanded and then contracted, the ink pressure in the pressure generating chamber 22 is increased and ink droplets are ejected from the nozzle openings 17.
[0050]
That is, in the recording head 4, the capacity of the corresponding pressure chamber 22 changes as the piezoelectric vibrator 21 is charged / discharged. By utilizing such pressure fluctuations in the pressure chamber 22, ink droplets can be ejected from the nozzle openings 17, or the meniscus (the free surface of the ink exposed at the nozzle openings 17) can be finely vibrated.
[0051]
Instead of the above-described longitudinal vibration mode piezoelectric vibrator 21, a so-called flexural vibration mode piezoelectric vibrator may be used. The piezoelectric vibrator in the flexural vibration mode is a piezoelectric vibrator that contracts the pressure chamber by deformation due to charging and expands the pressure chamber by deformation due to discharge.
[0052]
In this case, the recording head 4 is a multicolor recording head capable of recording a plurality of different types of colors. The multicolor recording head includes a plurality of head units, and the type of ink used for each head unit is set.
[0053]
The recording head 4 of the present embodiment includes a black head unit capable of ejecting black ink, a cyan head unit capable of ejecting cyan ink, a magenta head unit capable of ejecting magenta ink, and a yellow capable of ejecting yellow ink. A head unit. Each head unit communicates with each ink storage chamber of the corresponding ink cartridge 2a, 2b. Each head unit has the configuration described with reference to FIG. 4, and a nozzle array including a plurality of nozzle openings 17 is arranged in each ink color (BK, C, M, Y).
[0054]
Note that the ink droplet ejection characteristics of each nozzle opening 17 in the head member 4 tend to match each nozzle row mainly for manufacturing reasons. Accordingly, the drive signal for driving each piezoelectric vibrator 21 can be adjusted for each nozzle row (in this case, for each color) as described later.
[0055]
Next, the electrical configuration of the printer 1 will be described. As shown in FIG. 6, the ink jet printer 1 includes a printer controller 30 and a print engine 31.
[0056]
The printer controller 30 includes an external interface (external I / F) 32, a RAM 33 that temporarily stores various data, a ROM 34 that stores a control program, a control unit 11 that includes a CPU, a clock, and the like. An oscillation circuit 35 that generates a signal, a drive signal generation circuit 36 that generates a drive signal to be supplied to the recording head 4, and dot pattern data (bitmap data) developed based on the drive signal and print data Etc., and an internal interface (internal I / F) 37 for transmitting the information to the print engine 31.
[0057]
The external I / F 32 receives print data including, for example, a character code, a graphic function, image data, and the like from a host computer (not shown). In addition, a busy signal (BUSY) and an acknowledge signal (ACK) are output to the host computer or the like through the external I / F 32.
[0058]
The RAM 33 has a reception buffer, an intermediate buffer, an output buffer, and a work memory (not shown). The reception buffer temporarily stores the print data received via the external I / F 32, the intermediate buffer stores the intermediate code data converted by the control unit 11, and the output buffer stores dot pattern data. Remember. Here, the dot pattern data is print data obtained by decoding (translating) intermediate code data (for example, gradation data).
[0059]
In addition to a control program (control routine) for performing various data processing, the ROM 34 stores font data, graphic functions, and the like. Further, the ROM 34 also stores setting data for maintenance operation as maintenance information holding means. The ROM 34 (or an EEPROM (not shown)) stores a color adjustment value correction coefficient group, which will be described later, as a color tone confirmation mode data storage unit.
[0060]
The control unit 11 performs various controls according to a control program stored in the ROM 34. For example, the print data in the reception buffer is read and the print data is converted into intermediate code data, and the intermediate code data is stored in the intermediate buffer. In addition, the control unit 11 analyzes the intermediate code data read from the intermediate buffer and develops (decodes) it into dot pattern data by referring to the font data and graphic functions stored in the ROM 34. Then, the control unit 11 stores the dot pattern data in the output buffer after performing the necessary decoration processing.
[0061]
If dot pattern data for one line that can be recorded by one main scan of the recording head 4 is obtained, the dot pattern data for one line is sequentially transferred from the output buffer to the recording head 4 through the internal I / F 37. Output to the electric drive system 39, the carriage 5 is scanned, and printing for one line is performed. When dot pattern data for one line is output from the output buffer, the developed intermediate code data is erased from the intermediate buffer, and the development process for the next intermediate code data is performed.
[0062]
Further, the control unit 11 controls a maintenance operation (recovery operation) performed prior to the recording operation by the recording head 4.
[0063]
The print engine 31 includes a paper feed motor 13 as a paper feed mechanism, a pulse motor 7 as a head scanning mechanism, and an electric drive system 39 of the recording head 4.
[0064]
Next, the electric drive system 39 of the recording head 4 will be described. As shown in FIG. 6, the electric drive system 39 includes a decoder 50, a shift register circuit 40, a latch circuit 41, a level shifter circuit 42, a switch circuit 43, and the piezoelectric vibrator 21 that are electrically connected in order. These decoder 50, shift register circuit 40, latch circuit 41, level shifter circuit 42, switch circuit 43, and piezoelectric vibrator 21 are provided for each nozzle opening 17 of the recording head 4.
[0065]
In this electric drive system 39, when the pulse selection data (SP data) applied to the switch circuit 43 is “1”, the switch circuit 43 is connected and the pulse waveform in the drive signal is directly applied to the piezoelectric vibrator 21. Each piezoelectric vibrator 21 is deformed according to the pulse waveform in the drive signal. On the other hand, when the pulse selection data applied to the switch circuit 43 is “0”, the switch circuit 43 is disconnected and the supply of the drive signal to the piezoelectric vibrator 21 is cut off.
[0066]
Thus, a drive signal can be selectively supplied to each piezoelectric vibrator 21 based on the pulse selection data. For this reason, depending on the pulse selection data to be applied, ink droplets can be ejected from the nozzle openings 17 or the meniscus can be slightly vibrated.
[0067]
Here, details of the drive signal generation circuit 36 will be described with reference to FIG. As shown in FIG. 7, the drive signal generation circuit 36 includes a latch signal output unit 101 that outputs a plurality of latch signals in synchronization with the passing timing of each passing position of the recording head 4. The latch signal output unit 101 is connected to an encoder 102 that detects the position or movement amount of the recording head 4 in order to synchronize with the passing timing of each passing position of the recording head 4 (set for each recording pixel). ing.
[0068]
In addition, the drive signal generation circuit 36 has a channel signal output unit 103 that outputs a channel signal after each set time difference following the set time difference based on the set time difference with respect to the latch signal.
[0069]
A main body 105 is connected to the latch signal output unit 101 and the channel signal output unit 103.
[0070]
The main body unit 105 outputs a latch pulse waveform (first pulse signal PS1 in this case) that appears in synchronization with the output timing of the latch signal while the recording head 4 is moving, and a channel signal output by the channel signal output unit 103. A drive signal (A: see FIG. 8) having a channel pulse waveform (in this case, the second pulse signal PS2) appearing in accordance with the timing in that order is generated.
[0071]
As described above, the ink droplet ejection characteristics of each nozzle opening 17 in the head member 4 may differ for each nozzle row mainly for manufacturing reasons. In such a case, the design drive signals (the first pulse signal PS1 and the second pulse signal PS2) are corrected in order to set the amount of ink droplets ejected from the nozzle openings as designed. Is preferred.
[0072]
Therefore, a column error correction unit 105a is connected to the main body unit 105 of the present embodiment. The column error correction unit 105a is configured to increase or decrease the amplitude of the drive signal generated by the main body unit 105 for each nozzle column based on the ink droplet ejection characteristics for each nozzle column measured in advance.
[0073]
Specifically, a “color adjustment value” is given for each nozzle row, that is, for each ink color, based on the ink droplet ejection characteristics for each nozzle row measured in advance. For example, when the weight of ejected ink droplets in the cyan row is 10% greater than the designed value, the color adjustment value for the cyan row is set to 10%. Conversely, when the weight of the ejected ink droplets in the yellow row is 10% less than the designed value, the color adjustment value of the yellow row is set to -10%.
[0074]
The “color adjustment value” as described above is stored in a storage device (not shown) mounted on the recording head 4.
[0075]
The column error correction unit 105a reads the “color adjustment value” for each color from a storage device (not shown) of the recording head 4 so that the ink droplet ejection characteristics for each nozzle column (each color) are offset. The main body 105 is controlled to correct the drive signal.
[0076]
Specifically, for a color (nozzle row) having a color adjustment value of 10%, the amplitude of the drive signal is reduced so that the ink droplet ejection amount is suppressed by 10%. Conversely, for a color (nozzle row) with a color adjustment value of −10%, the amplitude of the drive signal is increased so that the ink droplet ejection amount is increased by 10%.
[0077]
Now, in the printer 1 according to the present embodiment, immediately before shipment as a product, the adjustment operator performs color tone adjustment regarding the distance (PG) between each nozzle opening and the recording paper. For this reason, the printer of the present embodiment has a color tone confirmation input unit 205 to which a color tone confirmation command is input. In addition, the printer 1 according to the present embodiment includes a color tone confirmation control unit 210 that controls the drive signal generation circuit 36, the control unit 11 (control main body unit), the head operation mechanism, and the paper feed mechanism in accordance with a color tone confirmation command. Yes.
[0078]
The color tone confirmation control unit 210 uses the drive signal (for example, drive signal A: see FIG. 8) in a state where the PG adjustment lever 19 is set as the reference position, and applies solid coating on the recording paper 12 having a reference thickness. A jet-like liquid mixture part is formed. In the present embodiment, the jet liquid mixture portion is a gray solid-tone solid pattern formed of cyan ink, magenta ink, and yellow ink.
[0079]
Then, the position of the PG adjustment lever 19 is changed with respect to the same recording paper 12, and the drive signal for each color (each nozzle row) is changed little by little. In this case, for each color (each nozzle row) ) Is gradually increased or decreased little by little to form a plurality of solid coating-like jet liquid mixing portions having slightly different color tones. However, each of the jetting liquid mixing portions is a gray solid-tone solid pattern formed of cyan ink, magenta ink, and yellow ink.
[0080]
Here, the color tone confirmation control unit 210 according to the present embodiment does not directly correct the amplitude of the drive signal for each color (for each nozzle row), but for each color read by the column error correction unit 105a. The "adjustment value" is modified. Specifically, for example, a color adjustment value correction coefficient group stored in advance in the ROM 34 or the like is multiplied by the “color adjustment value” for each color. An example of a color adjustment value correction coefficient group is shown in FIG.
[0081]
The adjustment operator selects the color tone of the ejected liquid mixing unit on the recording paper 12 formed by the reference printer from the plurality of ejected liquid mixing units formed on the recording paper 12 for each position of each PG adjustment lever 19. Select one of the jet liquid mixing parts that best matches. Then, the color adjustment value correction coefficient group corresponding to the selected jet liquid mixing unit is set in the liquid ratio storage unit 212 (see FIG. 7) in correspondence with the thickness of the recording paper 12.
[0082]
Here, the liquid ratio storage unit 212 of the present embodiment stores the correction coefficient group of the color adjustment value in association with the distance (PG) between each nozzle opening 17 and the recording paper 12. The distance (PG) between each nozzle opening 17 and the recording paper 12 is obtained by subtracting the thickness of the recording paper 12 from the distance between the moving track of the nozzle openings 17 and the support surface of the recording paper 12 by the paper feeding mechanism. Can be easily obtained.
[0083]
The operation of selecting, for each PG adjustment lever position, one of the ejected liquid mixing portions that most closely matches the color tone of the ejected liquid mixing portion on the recording paper 12 formed by the reference printer is the visual inspection of the adjusting operator. Or may be performed using a colorimeter.
[0084]
For example, FIG. 10 is an example of data obtained by evaluating a jet liquid mixing unit formed on a recording paper with different PGs using the same color adjustment value (correction coefficient group) using a colorimeter. In the example of FIG. 10, when PG is increased, the hue changes from the lower right to the upper left in the a ^* b ^* space. This means that the hue changes from magenta to green. Therefore, in order to match the hue (hue) when PG is increased to the hue (hue) when PG is small, the ejection amount of magenta ink is increased and the ejection amount of yellow ink and cyan ink is suppressed. It is effective to perform a color adjustment value adjustment. Therefore, a correction coefficient group of color adjustment values that can perform such color adjustment value adjustment is set in the liquid ratio storage unit 212.
[0085]
FIG. 11 shows another example of data obtained by evaluating, using a colorimeter, an ejection liquid mixing unit formed on a recording sheet with different PGs using the same color adjustment value (correction coefficient group). Similarly to the data example of FIG. 11, the description described for the data example of FIG. 10 is similarly applicable.
[0086]
The liquid ratio storage unit 212 of the present embodiment stores a correction coefficient group of color adjustment values corresponding to each PG as table data. In a simpler mode, the liquid ratio storage unit 212 uses the color adjustment value as binarized data based on whether or not the PG is sufficient to separate the main ink droplet and the satellite droplet. The correction coefficient group can be stored.
[0087]
Now, in the printer 1 according to the present embodiment, data of the recording paper 12 used by the user during use after purchase as a product is input. For this reason, the printer of this embodiment has a recording paper information input unit 206 for inputting recording paper information (see FIG. 6).
[0088]
Further, the printer 1 of the present embodiment derives the thickness of the recording paper 12 from the recording paper information input to the recording paper information input unit 206, and the recording paper 12 by the movement trajectory of the nozzle opening 17 and the paper feed mechanism. PG deriving unit 211 (an example of a distance identifying unit) that obtains a PG when the recording paper 12 is used based on the distance to the support surface and the derived thickness of the recording paper 12 (FIG. 7). reference).
[0089]
The recording paper information may be information such as the model number of the recording paper 12 in addition to the thickness information of the recording paper 12. In the latter case, the PG deriving unit 211 stores in advance table data that associates the model number of the recording sheet with the thickness of the recording sheet or the PG at this time.
[0090]
The printer 1 according to the present embodiment reads out the color adjustment value correction coefficient group corresponding to the PG obtained by the PG deriving unit 211 from the liquid ratio storage unit 212 and uses the color adjustment value correction coefficient group. And a PG adjustment unit 213 that performs color adjustment value adjustment (see FIG. 7).
[0091]
It is also possible to directly measure PG by providing a distance sensor for measuring the distance to the surface of the recording paper 12 at the same height position as the nozzle opening 17 of the carriage 5. Further, the PG information may be acquired by attaching a sensor to the PG adjustment lever 19.
[0092]
According to the present embodiment, based on the PG identified by the PG deriving unit 211, the relative proportion of the amount of each liquid ejected from each nozzle opening 17 is determined as the correction coefficient for the color adjustment value corresponding to the PG. Depending on the group, it can be adjusted to the desired ratio. As a result, it is possible to appropriately compensate for changes in landing characteristics due to overlapping of the main droplets and satellite droplets of each liquid upon landing, in this case, changes in color tone.
[0093]
In the above, the pressure generating element (an example of the pressure changing unit) that changes the volume of the pressure chamber 22 is not limited to the piezoelectric vibrator 21. For example, a magnetostrictive element may be used as a pressure generating element, and the pressure chamber 22 may be expanded and contracted by the magnetostrictive element to cause pressure fluctuations, or a heating element may be used as the pressure generating element. You may comprise so that a pressure fluctuation may be produced in the pressure chamber 22 by the bubble expand | swelled and shrink | contracted with a heat | fever. In this case, a method of changing the pulse width of the drive signal is more preferable as a method of changing the ink droplet discharge amount.
[0094]
As described above, the printer controller 30 can be configured by a computer system. However, a program for causing the computer system to realize each element and a computer-readable recording medium 201 that records the program are also subject to protection in this case. It is.
[0095]
Further, when each of the above elements is realized by a program such as an OS that operates on a computer system, a program including various instructions for controlling the program such as the OS and a recording medium 202 that records the program are also included in the present invention. It is a protection target.
[0096]
Here, the recording media 201 and 202 include not only a floppy disk or the like that can be recognized as a single unit, but also a network that propagates various signals.
[0097]
Although the above description has been made with respect to an ink jet recording apparatus, the present invention is intended for a wide range of liquid ejecting apparatuses in general. As an example of the liquid, in addition to ink, glue, nail polish or the like can be used.
[0098]
【The invention's effect】
As described above, according to the present invention, based on the distance identified by the distance identifying unit, the relative proportion of the amount of each liquid ejected from each nozzle opening is adjusted to a desired proportion corresponding to the distance. obtain. For this reason, it is possible to suitably compensate for a change in landing characteristics caused by, for example, an overlap at the time of landing between the main droplet and the satellite droplet of each liquid.
[0099]
In particular, when the present invention is applied to an ink jet type color recording apparatus, it is possible to obtain the same color tone recording result even if the PG is changed, and furthermore, the color tone due to PG variations among individual recording apparatuses caused by assembly errors. Variations can also be suitably compensated.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of an ink jet recording apparatus according to an embodiment of the present invention.
FIGS. 2A and 2B are schematic diagrams for explaining a scanning range of a recording head. FIG. 2A shows a scanning range of a printer that performs unidirectional recording, and FIG. 2B shows a scanning range of a printer that performs bidirectional recording.
FIGS. 3A and 3B are schematic diagrams for explaining the operation of the recording head, in which FIG. 3A shows a state where the recording head is positioned at the standby position, and FIG. 3B shows a state where the recording head is moved from the standby position to the recording area side; ) Shows the state when returning from the recording area side to the standby position, and (d) shows the state where it is located at the home position.
FIG. 4 is a diagram illustrating a configuration of a recording head.
FIG. 5 is a diagram illustrating a nozzle row for each color.
FIG. 6 is a schematic block diagram illustrating an electrical configuration of a recording head.
FIG. 7 is a schematic block diagram showing a drive signal generation circuit.
FIG. 8 is a diagram illustrating an example of a drive signal.
FIG. 9 is a table showing an example of a color adjustment value correction coefficient group;
FIG. 10 is a diagram illustrating an example of data obtained by evaluating a jet liquid mixing unit formed on recording paper of different PGs using the same color adjustment value using a colorimeter.
FIG. 11 is a diagram illustrating another example of data obtained by evaluating, using a colorimeter, an ejection liquid mixing unit formed on recording paper of different PGs using the same color adjustment value.
FIG. 12 is a diagram for explaining an influence of a distance between each nozzle opening and a recording sheet on a hue difference.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Inkjet printer 2a Black ink cartridge 2b Color ink cartridge 3 Cartridge holder part 4 Recording head 5 Carriage 6 Guide member 7 Pulse motor 8 Drive pulley 9 Reverse pulley 10 Timing belt 11 Control part 12 Recording paper 13 Paper feed motor 14 Paper feed roller 15 Cap member 16 Nozzle plate 17 Nozzle opening 18 Ink receiving member 19 PG adjustment lever 21 Piezoelectric vibrator 21a Comb-shaped tip 22 Pressure generating chamber 30 Printer controller 31 Print engine 32 External interface 33 RAM
34 ROM
35 Oscillation circuit 36 Drive signal generation circuit 37 Internal interface 39 Recording head electric drive system 40 Shift register circuit 41 Latch circuit 42 Level shifter circuit 43 Switch circuit 50 Decorator 71 Case 72 Storage chamber 74 Channel unit 75 Channel formation plate 77 Elastic plate 80 Nozzle opening 82 Ink supply part 83 Common ink chamber 84 Ink supply pipe 87 Stainless steel plate 88 Elastic film 89 Island part 101 Latch signal output part 102 Encoder 103 Channel signal output part 105 Main part 105a Column error correction part 200 Recording medium 201 Recording Medium 205 Color tone confirmation command input unit 206 Recording paper information input unit 210 Color tone confirmation control unit 211 PG derivation unit 212 Liquid ratio storage unit 213 PG adjustment unit

Claims (15)

A head member having a plurality of nozzle openings;
A plurality of pressure variation means for ejecting the liquid by varying the pressure of the liquid in each nozzle opening;
An ejected medium holding unit for holding the liquid ejected medium;
A moving mechanism for moving the head member relatively in parallel with the liquid ejection medium so that the plurality of nozzle openings of the head member pass through the position facing the liquid ejection medium;
Drive signal output means for outputting a drive signal to each pressure fluctuation means;
A control main body for ejecting liquid from each nozzle opening by driving each pressure variation means based on the drive signal during movement of the head member;
A distance identifying unit that identifies the distance between the movement trajectory of the plurality of nozzle openings of the head member and the liquid ejection medium;
Based on the distance identified by the distance identifying unit, the drive signal is output so that the relative ratio of the amount of each liquid ejected from each nozzle opening is a desired ratio corresponding to the distance. A distance adjusting unit for controlling the output means;
With
The distance adjustment unit is connected to a liquid ratio storage unit that stores a desired ratio of the amount of each liquid to be ejected from each nozzle opening in association with the distance identified by the distance identification unit,
The liquid ratio storage unit indicates a desired ratio of the amount of each liquid to be ejected from each nozzle opening, and the distance identified by the distance identification unit is a distance sufficient to achieve separation of the main droplet and the satellite droplet. A liquid ejecting apparatus comprising: at least binarized and stored based on whether or not there is. Each nozzle opening is divided into a plurality of nozzle opening groups to which liquids of different colors are supplied,
The liquid ejecting apparatus according to claim 1, wherein the drive signal output unit outputs a drive signal for each pressure variation unit group corresponding to each nozzle opening group. The plurality of nozzle openings is at least 3 or more,
The liquid ejecting apparatus according to claim 2, wherein the different color liquids are a cyan liquid, a magenta liquid, and a yellow liquid. The distance between the movement trajectory of the plurality of nozzle openings of the head member and the liquid ejection medium is the distance between the movement trajectory of the plurality of nozzle openings of the head member and the support surface that supports the liquid ejection medium of the ejection medium holding unit. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is obtained from a thickness of the liquid ejected medium. The liquid ejecting apparatus according to claim 1, further comprising a sensor that detects a distance between a movement trajectory of the plurality of nozzle openings of the head member and the liquid ejection medium. 4. A PG adjustment mechanism capable of changing a distance between a movement trajectory of a plurality of nozzle openings of a head member and a liquid ejection medium and further capable of acquiring information related to the distance. The liquid ejecting apparatus according to any one of the above. The liquid ratio storage unit stores a desired ratio of the amount of each liquid to be ejected from each nozzle opening as table data corresponding to the distance identified by the distance identification unit. The liquid ejecting apparatus according to any one of 1 to 6. The liquid ejecting apparatus according to claim 1, wherein the distance adjusting unit is configured to increase or decrease an amplitude of the drive signal by using the drive signal output unit. The liquid ejecting apparatus according to claim 1, wherein the distance adjusting unit is configured to increase or decrease a pulse width of the driving signal by using the driving signal output unit. A head member having a plurality of nozzle openings;
A plurality of pressure variation means for ejecting the liquid by varying the pressure of the liquid in each nozzle opening;
An ejected medium holding unit for holding the liquid ejected medium;
A moving mechanism for moving the head member relatively in parallel with the liquid ejection medium so that the plurality of nozzle openings of the head member pass through the position facing the liquid ejection medium;
An apparatus for controlling a liquid ejecting apparatus comprising:
Drive signal output means for outputting a drive signal to each pressure fluctuation means;
A control main body for ejecting liquid from each nozzle opening by driving each pressure variation means based on the drive signal during movement of the head member;
A distance identifying unit that identifies the distance between the movement trajectory of the plurality of nozzle openings of the head member and the liquid ejection medium;
Based on the distance identified by the distance identifying unit, the drive signal is output so that the relative ratio of the amount of each liquid ejected from each nozzle opening is a desired ratio corresponding to the distance. A distance adjusting unit for controlling the output means;
With
The distance adjustment unit is connected to a liquid ratio storage unit that stores a desired ratio of the amount of each liquid to be ejected from each nozzle opening in association with the distance identified by the distance identification unit,
The liquid ratio storage unit indicates a desired ratio of the amount of each liquid to be ejected from each nozzle opening, and the distance identified by the distance identification unit is a distance sufficient to achieve separation of the main droplet and the satellite droplet. A control device characterized by storing at least a binary value based on whether or not there is. Each nozzle opening is divided into a plurality of nozzle opening groups to which liquids of different colors are supplied,
The control device according to claim 10, wherein the drive signal output means outputs a drive signal for each pressure fluctuation means group corresponding to each nozzle opening group. The distance between the movement trajectory of the plurality of nozzle openings of the head member and the liquid ejection medium is the distance between the movement trajectory of the plurality of nozzle openings of the head member and the support surface that supports the liquid ejection medium of the ejection medium holding unit. 12. The control device according to claim 10, wherein the control device is obtained from the thickness of the liquid ejection medium. The control device according to claim 10, wherein the control device is connected to a sensor that detects a distance between a movement trajectory of the plurality of nozzle openings of the head member and the liquid ejection medium. 12. The distance between the movement trajectory of the plurality of nozzle openings of the head member and the liquid ejection medium can be changed, and is connected to a PG adjustment mechanism capable of acquiring information related to the distance. The control device described in 1. The liquid ratio storage unit stores a desired ratio of the amount of each liquid to be ejected from each nozzle opening as table data corresponding to the distance identified by the distance identification unit. The control apparatus in any one of thru | or 14.

Images