JP2004042427A - Printer and adjusting method of printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer which facilitates an adjustment of a voltage to be impressed to a plurality of heads, miniaturizes a head driving circuit and is capable of high-speed and beautiful printing, and to provide an adjusting method of a printer. <P>SOLUTION: In the printer which is equipped with the head driving circuit for discharging ink drops by a predetermined ink discharging condition from a plurality of heads, and prints picture information outputted from a picture information output means, a first voltage adjusting means for adjusting the voltage to be impressed in common to the plurality of heads, and a second voltage adjusting means for adjusting the voltage to be impressed in accordance with individual differences of each head are set at the head driving circuit. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a printing apparatus that prints image information output from image information output means by ejecting ink droplets from a head, and particularly to ejecting ink droplets from a plurality of heads under predetermined ink ejection conditions. And a method for adjusting the printing apparatus.
[0002]
[Prior art]
A device that prints image information such as characters, symbols, and images output from an image information output unit by discharging ink from a plurality of heads is referred to as an ink jet printer. Is commercially available as a simple printing device capable of printing image information and the like.
[0003]
In order to print image information beautifully and accurately, it is necessary to adjust the head drive voltage of the head drive circuit so that ink is ejected from the head under predetermined ink ejection conditions. For the adjustment, it was necessary to adjust the voltage applied to each head in order to stabilize the ejection speed of the ink droplets ejected from the head, the landing accuracy of the ink droplets, and the dot diameter.
[0004]
Conventional head drive circuits are generally provided integrally with the head and applied to individual heads, because the head drive circuit generally transmits a head drive waveform to the head appropriately and performs an operation of accurately ejecting ink droplets. A voltage adjusting circuit for adjusting the voltage, and a single power supply for supplying a voltage to each head so as not to be affected by voltage fluctuations or the like; The adjustment has been performed such that the ejection speed of the ink droplets ejected from the nozzle is constant.
[0005]
Therefore, as the number of heads increases, the voltage applied to the head drive circuit increases, and inevitably an electric resistance element, a transistor, or an electric circuit element such as an FET for adjusting these voltages is required. Since the ink becomes large, the amount of heat generated also increases, and the above-mentioned problem of the viscosity change of the ink due to the increase in the amount of heat generated also occurs. It was necessary to provide a means, and it was getting larger and larger.
[0006]
The circuit board of the head drive circuit is generally mounted together with the head on a reciprocating carriage, so if the circuit board is large, the mass of the entire carriage increases. A large motor or the like with a large force is required.In addition, the inertia increases when the mass of the entire carriage increases, so that even when driven by a large motor or the like, the time required to reach a certain speed becomes longer, and Also, when stopping, the carriage cannot be stopped immediately, so that the speed of the carriage cannot be increased, and it has been difficult to perform a high-speed printing operation.
[0007]
In particular, in recent years, the printing of color images has increased, and reproducibility close to the original image has been required, so that the number of heads tends to further increase. A major problem is that the mass of the substrate has increased and the carriage cannot be moved at a high speed.
[0008]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and provides a printing apparatus and a printing apparatus adjustment method capable of easily adjusting a voltage applied to a plurality of heads, reducing the size of a head driving circuit, and performing high-speed and beautiful printing. Aim.
[0009]
[Means for Solving the Problems]
According to the present invention, as a result of examining factors for adjusting the head drive voltage, factors common to all heads (common factors) such as environmental temperature changes and individual factors (individual factors caused by individual differences of individual heads) are considered. Focusing on the two factors (individual factors), it has been found that the above problem can be solved by adjusting the head drive voltage corresponding to each factor.
[0010]
That is, the invention according to claim 1 includes a head driving circuit for ejecting ink droplets from a plurality of heads under predetermined ink ejection conditions, and a printing apparatus for printing image information output from image information output means. A first voltage adjusting means for adjusting a voltage applied to the plurality of heads in common; and a second voltage adjusting means for adjusting a voltage applied in accordance with the individual difference of each head. Is provided.
[0011]
Thus, adjustment by common factors relating to all heads such as environmental temperature change is performed by the first voltage adjusting means, and adjustment by individual factors such as ink viscosity that varies depending on individual differences of individual heads and the type of ink is performed by the second voltage adjusting means. The adjustment function is separated so that the adjustment can be performed separately by the voltage adjustment means.
[0012]
As a result, the adjustment of the head drive voltage in the head drive circuit becomes easy, and the range of the voltage to be adjusted for each head can be reduced. Therefore, the electric circuit element constituting the second voltage adjustment means for adjusting each head can be used. A small-sized one can be adopted, so that the head drive circuit can be composed entirely of a small-sized circuit board. Further, it is possible to provide a printing apparatus capable of suppressing the amount of heat generated from the circuit board, obtaining a stable ink discharge speed, and performing high-speed and clear printing.
[0013]
According to a second aspect of the present invention, in the first aspect, the first voltage adjusting means and the second voltage adjusting means are provided on different circuit boards.
[0014]
As a result, the size of the circuit board can be further reduced, the degree of freedom in the arrangement of the circuit board in the printing apparatus is increased, and in particular, the circuit board is easily mounted.
[0015]
According to a third aspect of the present invention, in the first or second aspect of the present invention, a circuit board provided with the second voltage adjusting means is provided on a carriage means which reciprocates with the plurality of heads mounted thereon. It is characterized by.
[0016]
As a result, only the circuit board provided with the second voltage adjusting means can be mounted on the carriage, which leads to a reduction in the weight of the carriage, the reciprocating movement of the carriage at an extremely high speed, and a high-speed printing operation. It became.
[0017]
According to a fourth aspect of the present invention, there is provided a method for adjusting a printing apparatus, comprising: a head drive circuit for ejecting ink droplets from a plurality of heads under predetermined ink ejection conditions, and printing image information output from image information output means. A first voltage adjustment step of adjusting a voltage applied commonly to the plurality of heads, and a second voltage adjustment step of adjusting a voltage applied according to individual differences between the individual heads, After the adjustment in the first voltage adjustment step is completed, the head drive circuit is adjusted by performing the adjustment in the second voltage adjustment step.
[0018]
This makes it possible to easily adjust each of the head drive circuits, shorten the time required for the adjustment work, enable efficient production of a printing device, and provide a method of adjusting a printing device capable of performing high-speed and clear printing. Is now available.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.
[0020]
FIG. 1 is an overall schematic diagram of a printing apparatus according to the present invention. FIG. 2 is a block diagram showing a circuit configuration of the printing apparatus according to the present invention. FIG. 3 is a schematic diagram illustrating a head drive circuit according to the present invention.
[0021]
The configuration of the printing apparatus of the present invention will be described with reference to FIG.
In the drawing, reference numeral 1 denotes a head having nozzles for ejecting ink droplets, 2 denotes a carriage on which the head 1 is mounted, 3 denotes capping means, 4 denotes cleaning means, 5 denotes a recording member, and 11 denotes a printing device. The housing 12 is a slide guide for the carriage 2 to reciprocate. In the printing apparatus of FIG. 1, only one head is described for simplifying the description of the configuration. Arrows A to D in FIG. 1 indicate stop positions of the head during a printing operation, where A is a capping position, B is a cleaning position, C is a first standby position, and D is a second standby position.
[0022]
The head 1 is a printing unit of an ink-jet printing apparatus for printing information such as characters and images (hereinafter referred to as image information and the like) by ejecting ink droplets from a plurality of nozzles having extremely small holes. The head drive circuit (not shown) generates mechanical distortion in the piezoelectric element or generates bubbles by a heat source to discharge ink droplets from the nozzles. Hereinafter, the printing apparatus according to the present invention is also referred to as an inkjet printer.
[0023]
The head 1 is also referred to as a head unit. For example, in the case of a head for printing a color image, the four color inks of yellow (Y), magenta (M), cyan (C), and black (K) are used for each of the densities. The head unit is composed of a total of eight heads in order to form a higher-definition color image by discharging dark and light inks from nozzles (not shown).
[0024]
Of course, the configuration of the head unit is not limited to eight, but is set according to the specifications of the ink jet printer, the type of ink to be used, and the like. There are only four colors of M, C and K, and a single color depending on the application.
[0025]
The carriage 2 mounts the head 1 to print image information and the like on a recording member 5 such as paper or a resin film or cloth, and reciprocates along a slide guide 12. The drive is controlled via a carriage drive mechanism (not shown) composed of gears, belts, and the like serving as a drive source.
[0026]
The carriage 2 may include a head drive circuit, an ink tank for ejection called an intermediate tank (not shown), and the like in addition to the head 1.
[0027]
The capping means 3 is provided to prevent the peripheral portion of the nozzle of the head 1 from drying too much when the head 1 does not perform a printing operation, so that the ink solidifies and the ink droplets cannot be ejected from the nozzle. Although not shown in detail, it is a mechanism or an apparatus for closing a cap (cap) on the nozzle surface side of the head 1. Generally, a moisturizing liquid or ink is contained in the cap. A spongy material moistened with the like is provided.
[0028]
In the embodiment of the present invention, when the carriage 2 is moved to a position where a cap can be formed when the head 1 does not perform a printing operation (hereinafter referred to as a capping position), a capping mechanism (shown in FIG. Is capped on the nozzle surface side of the head 1 so that when capped, a small amount of ink is ejected from the nozzle to prevent the spongy material from drying.
[0029]
The cleaning means 4 is provided for cleaning the nozzles due to droplets of ink droplets discharged from the nozzle peripheral portion of the head 1 (hereinafter referred to as a nozzle surface), paper dust and thread debris of the recording member 5, or dirt or dust in the atmosphere. This is to prevent the ink droplets from being ejected due to blockage and distorting the ink droplet ejection direction.The details are not shown in the figures, but in general, the nozzle surface is made of rubber spatula. Some are equipped with a suction mechanism that cleans by rubbing or wiping with a sponge-like object, and pressing the cap that is linked to the suction device against the nozzle face side to forcibly suction to clear the nozzle clogging. The operation of cleaning the nozzle surface of the head 1 or suctioning the nozzles by the cleaning means 4 is called a cleaning operation.
[0030]
When cleaning the nozzle surface (not shown) of the head 1, the head 1 is moved by the carriage 2 to a position where cleaning operation can be performed by the cleaning unit 4 (hereinafter referred to as a cleaning position) and stopped. Cleaning operation.
[0031]
The recording member 5 is a paper or resin film or cloth for printing image information or the like, and in a large-sized printing device, a member wound in a hollow roll enough to insert a mandrel is used. In many cases, at the time of printing, a predetermined length is repeatedly fed by a feeding device (not shown) according to the printing ability, and after printing, the sheet is cut by a cutter or the like provided on the carriage 2 and used. Depending on the specifications of the printing apparatus, a sheet-shaped recording member 5 cut to a predetermined size may be used.
[0032]
The slide guide 12 serves as a guide (guide) for the carriage 2 to reciprocate linearly and accurately. In many cases, the slide guide 12 is provided with a linear encoder or the like to obtain accurate movement information of the carriage 2.
[0033]
The housing 11 forms a printing device, and, in addition to the above-described units and members, not shown, mounts an ink tank, a control circuit, and various sensors and driving devices necessary for printing operation and the like. It is for covering and covering.
[0034]
A printing operation of the printing apparatus according to the embodiment of the present invention will be described.
When a print command is received from a control circuit (not shown) in a state where the head 1 mounted on the carriage 2 is at a capping position (arrow A) facing the capping means 3, the capping means 3 is turned on by a cap (not shown). ) Is removed from the head 1, and the carriage 2 is moved forward in the order of 2A, 2B and 2C to the left in the figure.
[0035]
When the cleaning position detection sensor (not shown) detects that the carriage 2 has reached the cleaning position (arrow B) facing the cleaning means 4, the control circuit firstly puts a sponge into a container such as a tray, for example. An ink-absorbing process is performed to eject ink from all nozzles of the head toward an ink-discharge processing device (not shown) that is provided with an ink-absorbing member and that can receive and process the discharged ink. Thereafter, the movement of the carriage 2 is stopped, and the cleaning means 4 cleans the nozzle surface of the head 1.
[0036]
When the cleaning means 4 completes the predetermined cleaning operation, the control circuit moves the carriage 2 forward again in the left direction in the figure.
[0037]
When an end face detection sensor (not shown) provided on the carriage 2 detects the side end face of the recording member 5, a margin or a printing area on both sides which is set in advance based on a preset width dimension of the recording member 5. From the set print start position, the nozzles of the head 1 eject ink, start printing based on data such as image information stored in a memory (not shown) of the control circuit, and end the set print end. The printing ends at the position, but the carriage 2 further advances to the second standby position (arrow D), and the second standby position detection sensor (not shown) moves the carriage 2 to the second standby position (arrow D). When the control circuit detects that the carriage 2 has been reached, the control circuit stops the movement of the carriage 2.
[0038]
Thereafter, the control circuit starts the backward movement of the carriage 2 in the direction of the first standby position (arrow C), and the end surface sensor provided on the carriage 2 detects the side end surface of the recording member 5 similarly to the forward movement of the carriage 2. Is detected, printing is started from the position passing through the set margin, and printing is ended at the set printing end position. However, the carriage 2 further advances to the first standby position (arrow C) and When the standby position detecting sensor (not shown) detects that the carriage 2 has reached the first standby position (arrow C), the control circuit stops the movement of the carriage 2.
[0039]
In other words, the control circuit instructs to repeat printing while reciprocating the carriage 2 within the range between the first standby position (arrow C) and the second standby position (arrow D) during printing. When the printing of data such as information is completed, the nozzle surface of the head 1 is cleaned at the cleaning position (arrow B), the nozzle surface of the head 1 is capped at the capping position (arrow A), and stopped. It instructs to prepare for the printing operation of data such as information.
[0040]
It should be noted that the control circuit performs a cleaning operation once and returns to the printing operation when a preset cleaning time has come, even during printing of data such as image information, during printing.
[0041]
The setting of the cleaning time is set according to the performance and accuracy of the head, and also changes depending on the state of data being printed or no data such as image information to be printed, that is, being in a standby state. However, in the embodiment of the present invention, when ink is continuously ejected from the nozzles of the head, a time period during which the predetermined performance and accuracy are not sufficiently realized is obtained in advance by an experiment, and Is set as a predetermined time, and the cleaning is executed when a predetermined time has elapsed from the time of the previous cleaning.
[0042]
However, the setting of the cleaning timing is not limited to this, and it is sufficient that the predetermined performance and accuracy of the head can be maintained. Therefore, the cleaning timing may be separately set in consideration of the situation such as printing or waiting. The data amount of the image information to be printed or the number of reciprocations of the carriage 2 may be set by another method.
[0043]
Further, in the embodiment of the present invention, the capping position (arrow A) from the right end in the drawing is taken into consideration by considering the moving direction of the carriage 2 so that the nozzle surface of the head 1 can be easily cleaned at the time of first printing. Although the position (arrow B) and the moving position are set, the order of the arrangement may be changed in consideration of the arrangement and operation of various units of the printing apparatus, and the arrangement may be reversed. The carriage 2 may be moved from the left end position in the drawing.
[0044]
In the embodiment of the present invention, a plurality of sensors are used to detect the moving position of the carriage 2 and the like. However, the number of sensors and the control method for stopping the movement are not limited to this. The pulse drive method is such that the set pulse is given to a pulse motor or the like to control the drive, or the pulse drive method of controlling the drive by detecting the number of pulses detected by a linear encoder or the like, or the pulse drive method and a sensor are used. Speed control such as acceleration / deceleration and movement position control may be performed by using them together, and the carriage 2 may be controlled to move at a constant speed and stop at an accurate position.
[0045]
The circuit configuration of the printing apparatus according to the present invention will be described with reference to FIG.
In the figure, reference numeral 100 denotes a control circuit of the printing apparatus. The control circuit 100 includes a CPU 110, an information control circuit 120, an interface (I / F) 130, an image processing circuit 140, a drive control circuit 150, a display unit 170, and an operation unit. The drive control circuit 150 includes an input unit 180, a power supply circuit 160, and the like. The drive control circuit 150 includes a head unit 151, a carriage unit 152, a feeding unit 153 for driving the recording member 5 to a printing position, a cleaning unit 154, a capping unit 155, and the like. The information control circuit 120 includes an image data memory 121 for storing image data such as image information, and a print control data memory 122 for storing print control data associated with the image data. External as image information output means via interface (I / F) 130 Which is one of information equipment, for example, are connected to the host computer 200.
[0046]
The CPU 110 includes a control information storage unit (not shown) for storing control information such as a sequence according to a program of various printing modes and various control modes stored in advance, and a control circuit 100 based on the control information. I try to control the whole.
[0047]
The various printing modes include, for example, a black and white mode, a color image mode, a high-definition mode for image depiction, a standard mode, a simple mode in which printing of halftone colors is not performed, and a one-direction in which a printing direction can be selected. There are a print mode, a reciprocal print mode, etc., and an edit mode in which the layout of images to be printed can be changed and characters and the like can be entered. It is also possible to respond to various print mode commands from the computer 200 or the like.
[0048]
The information control circuit 120 converts input image information and the like into data suitable for the printing device in order to quickly and smoothly control the input and output of information with an external information device and the flow of information inside the printing device. A circuit having a data conversion function as an information conversion unit for converting, for example, converts input image information into image data suitable for a printing apparatus and stores the image data in the image data memory 121. The print operation and the like of the head unit 151 interlocked with the sending unit 153 are stored in the print control data memory 122 as control data for controlling based on image data.
[0049]
In addition to the image information described above, the information control circuit 120 transmits data and commands relating to an edit mode and a print mode input by the operation input unit 180 or commands for various print modes by the host computer 200 or the like. It also has a function to quickly transmit to various related circuits.
[0050]
The image processing circuit 140 has a function as an image information processing unit that converts image data and print control data into data suitable for a head or a nozzle using the data.
[0051]
For example, at the time of printing, the image data and the print control data stored in the image data memory 121 and the print control data memory 122 are read out via the information control circuit 120. Is transferred to the drive control circuit 150, and the head unit 151 is prepared to start the printing operation on the recording member 5 in conjunction with the carriage unit 152 and the feeding unit 153, and at the same time, the image data is transferred. The color signals and the dot signals for ejecting the ink are converted into dot signals and transferred to a head drive circuit (not shown) of the head means 151 so that the ink is ejected for each head or nozzle.
[0052]
The drive control circuit 150 drives and controls various units such as a head unit 151, a carriage unit 152, a feeding unit 153, a cleaning unit 154, a capping unit 155, and the like. A maintenance operation such as cleaning or capping and a printing operation for performing printing based on print control data and the like transferred from the image processing circuit 140 are operated based on a preset program or sequence by a command from the CPU 110. I have.
[0053]
In the embodiment of the present invention, the head unit 151 includes a head unit including a plurality of heads (for example, eight heads), a head driving circuit (not shown) for driving each head, and the like. 152.
[0054]
In the head drive circuit, the head drive voltage is adjusted so that the ink is ejected from the head under predetermined ink ejection conditions.
[0055]
Specifically, the ink ejection conditions include the ejection speed of the ink droplets ejected from the head, the landing accuracy of the ink droplets, the dot diameter, and the like, and are applied to individual heads to stabilize these conditions. Adjust the voltage to be applied.
[0056]
According to the present invention, the adjustment of the head drive voltage is performed by adjusting factors common to all the heads, such as environmental temperature change (hereinafter referred to as “adjustment by environmental temperature change”), the sensitivity difference between individual heads, the ink viscosity of the ink used, and the like. It has been found that the adjustment is made separately from the adjustment by the individual factor (hereinafter, referred to as the adjustment by the individual difference of each head).
[0057]
In the prior art, since the number of heads was small as a whole, adjustment was performed without discrimination between adjustment based on environmental temperature changes and adjustment based on individual differences of individual heads with one voltage adjustment circuit connected to one head. However, there was no problem, but when more accurate color image reproducibility was required, since multiple colors of ink were used, the ejection speed of each color ink droplet, the landing accuracy of the ink droplet, the dot diameter, etc. The need for precise control has arisen.
[0058]
In addition, since the number of heads has increased, accurate adjustment has become extremely difficult with the conventional method of comprehensively adjusting by changing the environmental temperature and adjusting by individual differences between individual heads.
[0059]
As the adjustment by the environmental temperature change, based on the characteristic of the ink that the ink viscosity increases as the temperature decreases and the ink viscosity decreases as the temperature increases, even if the ink viscosity changes in response to the environmental temperature change, In order to compensate for a predetermined ink ejection speed or the like, it is necessary to perform an adjustment called a level adjustment, which adjusts a voltage commonly applied to the entire head.
[0060]
In addition, as the adjustment based on the individual difference between the individual heads, it is necessary to adjust the sensitivity difference of the individual heads and to adjust the ink used.
[0061]
Adjusting the sensitivity difference between the individual heads is necessary even when the ink viscosity of the ink used in each head is constant, because the sensitivity of the head, that is, the performance of each head differs, The response speed and the ink ejection speed for the head drive waveform are corrected for each head, and the head sensitivity is adjusted to be uniform.
[0062]
The adjustment performed on the used ink means that even if the sensitivity of each head is constant, for example, when printing a color image, the viscosity of the used ink is different because a plurality of inks are used. The correction is performed in accordance with the viscosity of the ink to be used, and the ink is adjusted so that the ejection of the ink is uniform.
[0063]
Note that the adjustment performed on the ink used here is different from the case where the adjustment is performed based on the change in the ink viscosity due to the temperature change described in the above-described adjustment based on the environmental temperature. It is to be changed and corrected.
[0064]
Variations in ink viscosity occur depending on the type of ink, such as pigments and dyes. Even if the type of ink is the same, variations in colors, production lots, and the like may cause variations.
[0065]
The head drive circuit according to the embodiment of the present invention is connected to a plurality of heads, and requires adjustment by environmental temperature change and adjustment by individual difference of individual heads. A first voltage adjusting means for performing a so-called level adjustment for adjusting a voltage commonly applied to the entire head in order to compensate for a predetermined ink ejection speed or the like even if the ink viscosity changes, Individual heads, in order to adjust variations in the ink ejection speed and the like due to differences in sensitivity due to differences in the performance of individual heads and differences in the ink viscosity of the ink used for each head, according to the ink viscosity. And second voltage adjusting means for adjusting the voltage to be applied to the power supply.
[0066]
Then, based on predetermined ink discharge conditions, first, a level adjustment is performed by a first voltage adjusting means so as to satisfy a predetermined range of ink discharge speed within a voltage range defined as a reference, and then a second voltage adjustment is performed. The voltage adjustment means performs adjustment based on individual differences of individual heads.
[0067]
The predetermined ink ejection conditions are set according to the function, performance, specifications, and the like of the printing apparatus.
[0068]
Also, in the embodiment of the present invention, the head driving circuit converts the head driving waveform converted based on the image information by the image processing circuit 140 into the second voltage adjusting means during the printing operation, and Ink is appropriately ejected from the individual heads according to the drive waveform to print image information.
[0069]
In the embodiment of the present invention, although a detailed description is omitted, a head having a structure in which ink droplets are ejected by a piezoelectric element is used, and a head drive waveform is formed as a voltage waveform. And
[0070]
The carriage unit 152 reciprocates during the printing operation, and performs printing on the recording member such as paper supplied by the feeding unit 153 with ink discharged from the head of the head unit 151.
[0071]
The cleaning means 154 cleans the nozzle surface of the head and the like, and the capping means 155 removes and attaches a cap for preventing the head from drying.
[0072]
The printing apparatus according to the embodiment of the present invention basically prints data such as image information read from the host computer 200, for example. For example, in the edit mode, if there is a simple addition or deletion of a character such as a title, a comment, or a date, the operation input means 180 stores the character in the image data memory 121. The data such as characters is added to or deleted from the displayed image data on the display unit 170 so that the printing device can print.
[0073]
The display unit 170 is configured as, for example, a liquid crystal display device, and the CPU 110 can display a screen for commanding or inputting data with the operation input unit 180. For example, in the edit mode, addition or deletion of characters or the like is performed. For example, a screen display for editing can be displayed so that the user can confirm the execution status and the like during the operation of the printing apparatus.
[0074]
The operation input unit 180 includes, for example, a keyboard, a mouse, and the like. The operation input unit 180 can select various modes related to the operation of the printing apparatus, and can add or delete characters or the like in the editing mode. Information and data such as various instructions input by the means 180 are determined by the information control circuit 120 and the CPU 110 and the related image processing circuit 140, drive control circuit 150, display means 170, power supply circuit 160, or image data memory 121 , And the print control data memory 122 and the like.
[0075]
When the power is turned on by a power switch (not shown), the power supply circuit 160 activates the control circuit 100 and the like by a power supply activation circuit (not shown) provided in the power supply circuit 160 to perform a printing operation by various means. When the power is turned off by a power switch or a command from the CPU 110, the CPU 110 operates various units to predetermined positions and completes all the operations. (Not shown), all power is shut off.
[0076]
With reference to FIG. 3, a head drive circuit according to the present invention will be described.
FIG. 3A shows a conventional head drive circuit, and FIG. 3B shows a head drive circuit according to the embodiment of the present invention. ing.
[0077]
First, a conventional head drive circuit will be described with reference to FIG.
In the drawing, H (1) to H (n) represent n heads, and VAC (1) to VAC (n) are connected corresponding to the heads H (1) to H (n), respectively. 2 shows a voltage adjusting circuit for adjusting the voltage applied to the head. HW (1) to HW (n) are head drive waveforms input to the voltage adjustment circuits VAC (1) to VAC (n) to drive individual heads. Note that HV represents a head voltage applied to a head drive circuit including the heads H (1) to H (n), the voltage adjustment circuits VAC (1) to VAC (n), and the like.
[0078]
The voltage adjustment circuits VAC (1) to VAC (n) are adjusted based on predetermined ink ejection conditions. However, the voltage adjustment circuits VAC (1) to VAC (n) adjust voltages applied to individual heads on the same circuit board, that is, the above-described environmental temperature change. Since the adjustment is performed without discriminating between the adjustment and the adjustment based on the individual difference of each head, the range of the voltage to be adjusted is widened.
[0079]
When the head voltage HV is applied at a voltage of, for example, about 18 V, a current of about 1 A is applied at a voltage of about 9 V to each of the voltage adjustment circuits VAC (1) to VAC (n). In order to adjust this, it is necessary to constitute a circuit with large electric circuit elements such as a so-called power transistor, and the amount of heat generated by the circuit board is large.
[0080]
Therefore, it is necessary to devise a circuit design for heat dissipation and to incorporate a heat dissipation means (not shown) such as a heat dissipation device composed of a thin metal plate or the like. Had become.
[0081]
Although the detailed description of the operation of the head drive circuit is omitted, after the voltage applied to each head is adjusted based on predetermined ink discharge conditions, for example, the image information is output from the image processing circuit 140 in FIG. When the head drive waveforms HW (1) to HW (n) converted based on the above are input to the voltage adjustment circuits VAC (1) to VAC (n), the input head drive waveforms HW (1) to HW (n) ) Causes the heads H (1) to H (n) to operate, ejecting ink droplets, and printing image information.
[0082]
Referring to FIG. 3B, a head drive circuit according to the embodiment of the present invention will be described. Those having the same functions as those of the conventional head drive circuit shown in FIG. 3A are denoted by the same reference numerals.
[0083]
In the figure, VAC (M) is a first voltage adjusting circuit as first voltage adjusting means for adjusting a voltage commonly applied to the heads H (1) to H (n). VAC (P1) to VAC (Pn) are second voltage adjusting circuits as second voltage adjusting means for performing adjustment based on individual differences of individual heads.
[0084]
Then, heads H (1) to H (n) are connected to the second voltage adjustment circuits VAC (P1) to VAC (Pn), and head drive waveforms HW (1) to HW (n) for driving the heads are provided. After the voltage applied to each head is adjusted, for example, the head drive waveforms HW (1) to HW (H) converted based on the image information by the image processing circuit 140 in FIG. (N) are input to the second voltage adjustment circuits VAC (P1) to VAC (Pn), and the heads H (1) to H (n) are driven by the input head drive waveforms HW (1) to HW (n). When activated, ink droplets are ejected to print image information.
[0085]
Note that the second voltage adjustment circuit performs adjustment based on individual differences of individual heads, and in the embodiment of the present invention, when the head drive waveforms HW (1) to HW (n) are input, the heads are adjusted. Although the function of driving and ejecting ink droplets is provided, the function of driving the head and ejecting ink droplets may, of course, be performed by another circuit.
[0086]
The difference between the conventional head drive circuit and the head drive circuit according to the embodiment of the present invention is that the conventional head drive circuit has voltage adjustment circuits VAC (1) to VAC corresponding to heads H (1) to H (n). In (n), the adjustment is performed without discriminating between the adjustment based on the environmental temperature change and the adjustment based on the individual difference of the individual heads. The head drive circuit according to the embodiment of the present invention classifies adjustment based on environmental temperature change and adjustment based on individual differences of individual heads, and performs adjustment based on environmental temperature change common to all heads by a first voltage. The adjustment circuit VAC (M) performs the adjustment based on the individual differences of the individual heads in the second voltage adjustment circuits VAC (P1) to VAC (Pn). Therefore, the voltage adjustment circuits can be separated and the voltage to be adjusted can be adjusted. The width of Can fence, is to now allow the precise adjustment readily enables the fine adjustment of voltage.
[0087]
Then, upon adjustment, based on predetermined ink discharge conditions, for example, a reference voltage range and environmental temperature conditions set in advance for each voltage adjustment circuit, or conditions such as ink type and ink viscosity, etc. First, an environmental temperature common to the entire head is adjusted by adjusting means (not shown) of the first voltage adjusting circuit VAC (M) so as to satisfy the ink discharge speed in a predetermined range within a voltage range defined as a reference. After that, the voltage is adjusted by common factors such as, for example, and then adjusted by an adjusting means (not shown) of the second voltage adjusting circuits VAC (P1) to VAC (Pn). Is adjusted.
[0088]
By separating the voltage adjustment circuit in this manner, for example, when a voltage of about 18 V at the maximum is applied as the head voltage HV and the adjustment voltage range of each head is set to about 9 V as in the related art, When the head drive voltage is comprehensively adjusted on the same circuit board, the voltage adjustment circuits VAC (1) to VAC (n) have an adjustment voltage range of about 9 V and about 0.3 A for each head. However, in the embodiment of the present invention, for example, an adjustment voltage of about 5 V is applied to the first voltage adjustment circuit VAC (M), and the second voltage adjustment circuit VAC (M) is applied. (P1) to VAC (Pn) can be set to apply a current of about 0.3 A or less at a voltage of about 4 V, so that even if the first voltage adjustment circuit is provided, a comprehensive circuit is provided. The calorific value of The circuit elements used in the second voltage adjustment circuit for adjusting the head it is possible to reduce the size. In particular, it is possible to make fine adjustments due to differences in sensitivity between individual heads, slight differences in ink viscosity, and the like, so that accurate voltage adjustment can be easily performed.
[0089]
Therefore, the circuit elements to be used can be made smaller and the circuit board can be made smaller, so that the load such as the mass of the circuit board mounted on the carriage can be reduced, and the carriage can be moved at high speed.
[0090]
Further, by separating the voltage adjustment circuits, each voltage adjustment circuit can be formed on a separate circuit board, and the degree of freedom in arrangement is expanded.When the head drive circuit is mounted on the carriage, for example, The circuit boards of the second voltage adjustment circuits VAC (P1) to VAC (Pn) are mounted on the carriage, and the circuit board of the first voltage adjustment circuit VAC (M) can be arranged separately from the carriage. Further, the load such as the mass of the circuit board mounted on the carriage can be reduced, and the carriage can be moved at a higher speed.
[0091]
In addition, when the circuit board of the second voltage adjustment circuit is mounted on the carriage, the amount of heat generated by the circuit board of the second voltage adjustment circuit can be reduced. The heat generated by the circuit does not adversely affect the ink viscosity of the ink to be discharged, and a stable ink discharge speed and the like can be obtained.
[0092]
In the case where the first voltage adjustment circuit and the second voltage adjustment circuit are formed on separate circuit boards, even if an accident such as damage to any circuit board occurs, Since only the substrate needs to be replaced or repaired, it can be produced at low cost and in a short time.
[0093]
In addition, since the adjusting means (not shown) is also separated for each circuit board, the adjustment common to the entire head and the adjustment performed for each head are not mistakenly adjusted at the time of adjustment, and accurate adjustment can be performed in a short time. Work can be performed easily, and production efficiency can be improved.
[0094]
As described above, in the description of the head drive circuit according to the embodiment of the present invention, the head voltage HV and the voltage value and the current value applied to the first voltage adjustment circuit and the second voltage adjustment circuit have been described as examples. The voltage value and the current value change depending on the function and performance of the head to be used, the specifications of the printing apparatus, and the like, and do not limit these numerical values.
[0095]
Although the adjusting means is not particularly described, it is preferable that the adjusting operation is easy and fine adjustment can be performed. It goes without saying that such adjusting means may be used.
[0096]
Further, the circuit board used for the first voltage adjustment circuit and the second voltage adjustment circuit in the embodiment of the present invention is not limited to a rigid plate-shaped circuit board, but is thin and flexible. A circuit board made of a certain material or the like may be used, and a circuit board made of a resin material that is not easily affected by a solvent such as ink is preferable.
[0097]
【The invention's effect】
The voltage to be applied is adjusted by the first voltage adjusting means by the environmental temperature change, by the second voltage adjusting means by the individual difference of each head, and by performing each adjustment separately for each adjusting function. The current and current can be set in an appropriate balance, the range of voltage to be adjusted in each circuit can be reduced, and the electric circuit elements that compose the circuit can be small. It is possible to use a substrate, and it is possible to reciprocate at high speed even when mounted on a carriage.
[0098]
In addition, by separately creating the circuit boards for each adjustment function, each circuit board can be further miniaturized. For example, if only the circuit board constituting the second voltage adjusting means is mounted on the carriage, the mass is reduced. Since it can be further reduced, the carriage can reciprocate at a higher speed.
[0099]
In addition, since the adjustment function is separated for each adjustment function, the adjustment can be accurately performed without making a mistake between the adjustment based on the environmental temperature change and the adjustment based on the individual difference between the individual heads.
[0100]
In the unlikely event that one of the circuit boards is damaged, replacement or repair becomes easy, so that the cost of the head drive circuit can be reduced and the production of a printing device with high production efficiency can be achieved. It is possible to provide a printing apparatus and a method of adjusting the printing apparatus that can perform high-speed and clear printing without being affected by not only a change in environmental temperature but also a change in ink viscosity due to heat generation of a circuit board.
[Brief description of the drawings]
FIG. 1 is an overall schematic view of a printing apparatus according to the present invention.
FIG. 2 is a block diagram illustrating a circuit configuration of a printing apparatus according to the present invention.
FIG. 3 is a schematic diagram illustrating a head drive circuit according to the present invention.
[Explanation of symbols]
1 head
2 carriage
3 Capping means
4 Cleaning means
5 Recorded member
11 Case
12 slide guide
100 control circuit
110 CPU
120 Information control circuit
130 Interface (I / F)
140 Image processing circuit
150 Drive control circuit
160 power supply circuit
170 Display means
180 Operation input means
200 Host computer

Claims (4)

A printing apparatus for printing image information output from image information output means, comprising: a head drive circuit for discharging ink droplets from a plurality of heads under predetermined ink discharge conditions; A printing apparatus, wherein a first voltage adjusting means for adjusting a voltage and a second voltage adjusting means for adjusting a voltage to be applied according to an individual difference of each head are provided in the head drive circuit. The printing apparatus according to claim 1, wherein the first voltage adjusting unit and the second voltage adjusting unit are provided on different circuit boards. The printing apparatus according to claim 1, wherein a circuit board provided with the second voltage adjusting means is provided on a carriage means on which the plurality of heads are mounted and reciprocates. A head driving circuit for ejecting ink droplets from the plurality of heads under predetermined ink ejection conditions; and a method of adjusting a printing apparatus for printing image information output from image information output means. A first voltage adjusting step of adjusting a voltage to be applied to the head, and a second voltage adjusting step of adjusting a voltage to be applied according to an individual difference of each head. A method for adjusting the printing apparatus, wherein the adjustment of the head drive circuit is performed by performing the adjustment in the second voltage adjustment step after the completion of the above.

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