JPH0428561A - Recording device and recording head - Google Patents

Abstract

PURPOSE:To make density correction available in satisfactory conditions at any time even with a different recording head mounted after replacement by a method wherein a correction dataum is selected, based on selection data stored in a selection data storage means of a recording head, out of a plurality of correction data stored in a correction data storage means, and the correction is made on recordings made with a plurality of recording elements, based on the selected correction data. CONSTITUTION:A circuit processes four colors, Y, M, C, and K by time-sharing method. Correction pattern selecting signals 356-359 from each of head chips are switched in a selector 303 in accordance with a color synchronous signal 360 and is outputted to a ROM 30 as a correction pattern selecting signal 354. Head address signals 355 representing the addresses of 128 ejection ports in the head chips are supplied in accordance with the supply of video data, and thereby correction data for the correction patterns can be outputted for each of ejection ports. Operation for tables is selected with the correction data 353 taken as an address and the result of this operation is outputted as video data 352.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording head and a recording apparatus, and more particularly to a disposable recording head and a recording apparatus using the recording head.

[Prior Art] Recording methods used in recording apparatuses include a thermal transfer method in which ink from an ink ribbon or the like is transferred onto a recording medium using heat, and a thermal recording method is used in which recording is performed using heat on thermal paper; There is also an inkjet method in which recording is performed by ejecting ink to form ink dots on a recording medium.

Recording heads using these systems can be made smaller and lower in cost due to advances in manufacturing technology in recent years, contributing to the provision of simple and compact recording devices.

Among them, inkjet recording heads, especially inkjet recording heads that eject recording liquid (hereinafter referred to as ink) using thermal energy generated by electrothermal transducer elements, eject ink and generate flying liquid. It is possible to perform high-resolution recording because the ejection ports such as orifices for forming droplets can be arranged in a high density, and the overall size of the recording head can be easily made compact. It is possible to fully utilize the advantages of IC technology and micro-processing technology, where technological advances and reliability improvements have been remarkable in the semiconductor field, and it is easy to lengthen and planarize (two-dimensional). It is attracting particular attention because it is easy to implement multiple nozzles and high-density packaging, has good productivity during mass production, and can reduce manufacturing costs.

As described above, since the print head is provided at a low cost, it becomes possible to discard the print head after using it for a predetermined period of time and replace it with a new print head. Thereby, various advantages can be obtained, such as preventing deterioration of various parts constituting the recording head, such as electrothermal transducers, from affecting recording, and making it possible to always perform good recording.

[Problems to be Solved by the Invention] By the way, when manufacturing a recording head with a plurality of recording elements, the recording characteristics of each recording element, for example, in the case of an inkjet recording head, the size of the ejection port and the electrical It is difficult to manufacture a heat converter so that its conversion characteristics are strictly uniform, and when recording using such a recording head, density unevenness may occur over the entire recorded image. .

One effective method to prevent this is to examine the printing characteristics of each printhead when manufacturing the printhead, and store correction data for each print element based on the results in a predetermined storage means of the printing apparatus. There is a method in which this correction data is taken into consideration during recording.

However, in this method, when a so-called disposable type recording head as described above is used, if the recording head is changed due to replacement, the correction data stored in the recording apparatus may no longer be appropriate.

In addition, in order to avoid problems caused by such inconvenience of correction data in disposable type recording heads,
In order to avoid using correction data, if the recording characteristics of each recording element are examined during manufacturing and only those whose variations are within a predetermined range (a range in which the recording head is approximately uniform) are used, the yield will decrease and the recording head This will lead to an increase in costs.

The present invention has been made in order to solve problems particularly caused by replaceable type print heads regarding the correction of density unevenness caused by non-uniformity of print element characteristics in a print head having a plurality of print elements. Each has storage means that stores this correction data, and when it is installed in the recording device, this correction data is read out and correction is performed based on it, so that the recording head used can be changed by replacing it. It is an object of the present invention to provide a print head that can always perform good density correction even when the print head is used, and a print apparatus using the head.

[Means for Solving the Problems j] To this end, the present invention provides a recording head in which a plurality of recording elements are arranged for recording on a recording medium, and a recording head for correcting the density of recording by the plurality of recording elements. In a recording apparatus that performs recording using a recording head having a selection data storage means storing selection data for selecting correction data from a plurality of correction data, the correction data storage means storing the plurality of correction data; , select correction data from among a plurality of correction data stored in the correction data storage means based on the selection data stored in the selection data storage means of the recording head, and record the plurality of recordings based on the selected correction data. The present invention is characterized by comprising a correction means for correcting recording by the element.

In addition, the recording head has a plurality of recording elements arranged for recording on a recording medium, and a selection function for selecting correction data for correcting the density of recording by the plurality of recording elements from among the plurality of correction data. The present invention is characterized by comprising a selection data storage means storing data.

[Function] According to the above configuration, the correction data regarding the recording characteristics of the attached recording head is selected from a plurality of correction data based on the selection data possessed by this recording head, and this correction data The recording characteristics of the recording head are corrected.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIGS. 1A and 1B are a cross-sectional view and a perspective view of an inkjet recording apparatus according to an embodiment of the present invention. FIG. 1A shows details of a print head cartridge in which a print head and an ink tank are integrated in a state where it is installed in an apparatus.

In FIG. 1(A), reference numeral 106 denotes a head chip serving as a recording head constituting the main body of the inkjet cartridge C. As shown in the figure, the head chip 106 is
128 outlets 106 arranged at a density of 400 dpi
A, a top plate for configuring a liquid path 106B that communicates with each of these discharge ports and in which an electrothermal conversion element described below is arranged, and a common liquid path 112 that communicates in common with all of the liquid paths 106B;
An electrothermal transducer that generates thermal energy by applying electric pulses and ejects ink, electrode wiring for applying electric pulses to this electrothermal transducer, and control of the application of electric pulses based on recorded data. It is constructed by bonding a substrate (this substrate is not shown) on which a head driver and the like for the operation are disposed. The substrate also includes an EPROM 1 according to an embodiment of the present invention.
20 (indicated by the dotted chain line in the figure), and E
The PROM 120 stores selection data for selecting any one of the correction data shown in FIG. 5 (A1 to (D)).

Reference numeral 102 denotes an ink tank that is formed integrally with the head chip 106 and constitutes the recording head cartridge C. The inside of the ink tank 102 is provided with an absorber 101 for holding ink and a pair of electrodes for detecting the amount of ink.
is supplied to each liquid path 106B of the RAD chip. In addition, the ink tank 102 and the common liquid path 112 are connected to a filter 113 made of a porous material having a pore size that does not easily allow air bubbles to pass through.
are connected via. Furthermore, the ink tank 102
At the top of the head chip 10, fine air communication holes are provided through a hydrophobic open cell, and this atmospheric pressure causes the head chip 10 to
The ink held in the absorber 101 is supplied according to the ink consumption in step 6, and at this time, it is possible to prevent air bubbles from entering the ink.

114 is the head driver on the above-mentioned board, electrode wiring,
Furthermore, a connector 109 is used to electrically connect the electrodes in the ink tank 102 to a control section and a power source (not shown) of the apparatus of this embodiment, and a reference numeral 109 electrically connects the connector 114 and the control section, etc. Flexible cable for connection (its illustration is omitted in Figure 1 (B))
It is. Also, the EFROM configured in the head chip]
The contents of 20 are read by the control unit via these electrical connections.

In FIG. 1 (AI and (B)), the ink tank 10
2 and the Herad chip 106 are configured as an integrated cartridge C as described above, and can be attached to and detached from the carriage with a single touch by a mechanism not shown. Thereby, when the ink runs out, the cartridge C can be replaced with a new one. Further, the cartridge C is constructed independently for each color of magenta, yellow, cyan, and black, and is configured such that only the color for which ink has run out can be replaced.

The carriage 103 on which each cartridge C is mounted is driven by the drive force of a carriage motor (not shown) transmitted via a drive belt 52 connected to a part of the carriage 103, which moves the carriage shaft 1
17 while being guided in that direction (main scanning).

During this movement, the ejection port 106A of the head depth 106 is connected to the conveyance guide 116 of the recording medium 111 and the paper presser 10.
It faces a recording surface regulated by g, and recording is performed with ink ejected from ejection 0106A during this time. In addition, in accordance with the recording that occurs as the carriage 103 moves, the recording medium is conveyed on the guide 116 by the paper conveyance roller 105 and the paper discharge roller 115 in the direction of arrow A (sub-scanning direction) in FIG. be done. Through the above operations, a predetermined image of one character or the like is recorded on the recording medium 111 according to the recording data.

Figure 2 shows this situation. When printing on A4 size recording paper, 128 ejection quarters are recorded in one main scan, and 128 ejection ports are recorded in the sub-scanning direction. The paper is fed. By repeating the above operations, A4
It becomes possible to record on the entire size.

FIG. 3 shows the CPU, ROM, and R of the control unit of this example device.
It shows a block diagram of an image processing section and a reading system constituted by an AM or the like, and FIG. 4 is a block diagram showing details of a head correction section therein.

The inkjet recording device of this example is used together with an image reading device such as a scanner, and the original is color-separated through three color filters (red, green, and blue), and the information on each original is photoelectrically converted in the CCD 201. It is read by This photoelectrically converted data is amplified by an amplifier 202 and then sent to an A/D converter 2.
03, it is converted into 8-bit digital data.

The image data read by the image reading system as described above is input to the shading correction circuit 204 of the image processing section, and the unevenness of the CCD sensor and the unevenness of the reading optical system such as the light amount distribution is corrected. Next, the Log conversion circuit 205 converts cyan and magenta based on the corrected red, green, and blue signals.

Yellow density data is generated, and the OCR masking circuit 206 depicts the black component and performs calculations to remove color turbidity. Next, the γ conversion circuit 207 converts the color balance according to the density volume specified by the user, for example.

Further, the head correction circuit 208 corrects the head recording characteristics according to an embodiment of the present invention.

The details will be described later with reference to FIGS. 4 and 5.Next, the binarization circuit 209 performs binarization processing. As this processing method, an error diffusion method is used in this example. Next, the binarized data is transferred to the head driver 2.
10, and the head 106 of each color is driven based on this data.

The density correction process according to an embodiment of the present invention will be described below with reference to FIGS. 4 and 5. As described above, if there are variations in recording characteristics among the ejection ports of the head chip, density unevenness will occur if printing is performed using uniform density pattern data.

Such density unevenness causes, for example, differences in density at the boundaries of images recorded by each main scan, and the boundaries become noticeable. Therefore, in order to make this boundary less noticeable, it becomes necessary to correct the recording characteristics of the head.

FIG. 4 is a block diagram showing details of the head correction circuit shown in FIG. 3. In FIG.
This is a ROM that stores 16 types of correction patterns shown in A) to (P). The CPU of the control section is a Herad chip]
A correction pattern selection signal is received from the EPROM 120 of No. 06, and a correction pattern for each head is selected from the ROM 302 based on this signal. In other words, the circuit of this embodiment processes the four colors Y, M, and C in a time-division manner, and uses the correction pattern selection signals 356 to 359 from each head chip.
is switched in the selector 303 according to the color synchronization signal 360, and the ROM is switched as the correction pattern selection signal 354.
302, and thereby the correction pattern data is output from the ROM 302. Also, in the ROM302,
A head address signal 355 indicating the address of each of the 128 ejection ports of the head chip is video data (
The correction data of the correction pattern can be output for each ejection port.

Next, 301 is a ROM that stores a calculation table for outputting video data 352 corrected from video data 351 and correction data 353 for each ejection port of a correction pattern in ROM 302 . That is, the correction data 35
3 is used as an address to select an operation on the table, and the result of this operation is output as video data 352.

Next, to explain Fig. 5, Fig. 5 shows the ROM 30
2 shows correction pattern data stored with selection signals and ejection ports as addresses, the horizontal axis indicates the 1st to 128th ejection ports, and the vertical axis indicates density data to be corrected. "1°" in the center means no correction, and when this data becomes large, the correction is made to output a darker color, and when it becomes smaller, the correction is made to make the output lighter. Therefore, for example, Fig. 5 (A) This is a case where the recording characteristics of the ejection ports of the head chip 106 are uniform, so no correction is required. In FIG. Therefore, this data is used to correct the tingling of the discharge ports in the latter half.

Further, FIG. 5(C) also has the same tendency as FIG. 5(B), but the correction value is made smaller.

Below, a total of 16 types of correction patterns are shown in RO up to Figure 5 (P).
It is stored in M302.

In addition, the calculation table of the ROM 301 mentioned above is shown as follows:
It will look like this:

A8 to A16 Video (352) 0H ---- Video (351) ×0.5 In other words, using 00)1-FFH, which is output from the ROM 302 and corresponds to 256 levels of correction data, as an address,
Each calculation is stored in the ROM 301. For example, when the vertical axis in FIG. .

The selection data indicating which correction pattern to select for each print head is determined by measuring the print characteristics of the print head at the time of manufacture at the factory, and then selecting a correction pattern that will reduce density unevenness among the 16 patterns shown in Figure 5. It is selected from among them and written into the EPROM 120 of the head chip.

Note that as a means for the recording head to have data for selecting a correction pattern, for example, an IC card on which a number etc. related to the selected correction pattern is written is attached to a part of the recording apparatus at the same time as the recording head is attached. , it is possible to select a correction pattern by reading this.

In addition, such a card has a memory in which information about the lifespan of the recording head, such as the cumulative number of sheets printed and the number of recorded dots, is written, and the card is installed each time the recording device is used, so that the lifespan of these heads can be measured. A so-called key card may be used to manage the data and device operations, and the data for selecting the correction pattern may be stored in this card.

The present invention is most preferably applied to a so-called disposable type recording head that is configured to be detachable from the apparatus main body, but even if the present invention is a non-disposable type recording head, for example, it is necessary to maintain the apparatus. It is conceivable that a service person may replace the recording head as necessary in such cases, and the recording head and recording apparatus to which the present invention is applied will be effective in such cases as well.

Furthermore, in the above embodiment, a method was used in which the density in the video data was changed according to the head characteristics, and this was expressed as a dot pattern using a binarization circuit. The concentration may be changed by changing the pulse width of the applied voltage. For example, when making a light density ejection port darker, it is possible to correct the density by increasing the pulse width.

Furthermore, as a means of changing the characteristics of the recording head, it is also possible to control the current value flowing through the electrothermal transducer, etc.
In this case, it is possible to provide a constant current drive circuit for each ejection port and change the control current according to the correction pattern. For example, if a light density ejection port is to be made darker, it is possible to correct the density by increasing the current.

In addition, although the above embodiment has 16 types of correction patterns, it is clear that the number and characteristics of the patterns are not limited to the upper side.
It can be determined depending on the recording head used, usage environment, etc.

Furthermore, in the above embodiments, an inkjet type recording apparatus has been described, but the present invention is not limited to this, and the present invention can also be applied to apparatuses using thermal transfer type, thermal type, etc. recording heads. You can also do it.

(Others) The present invention brings about excellent effects particularly in a bubble jet type recording head and recording apparatus among inkjet recording types.

This is because such a system can achieve higher recording density and higher definition.

As for typical configurations and principles thereof, it is preferable to use the basic principles disclosed in, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740,796. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, it is necessary to arrange the liquid (ink) in accordance with the sheet and liquid path that hold it. The electrothermal converter that is
Generating thermal energy in the electrothermal transducer and producing film boiling on the thermally active surface of the recording head by applying at least one drive signal that corresponds to recorded information and provides a rapid temperature rise above nucleate boiling. As a result, bubbles in the liquid (ink) can be formed in a one-to-one correspondence with this drive signal, which is effective. The growth and contraction of the bubble causes liquid (ink) to be ejected through the ejection opening to form at least one droplet. If this drive signal is in the form of a pulse, bubble growth and contraction will occur immediately and appropriately.
Particularly responsive liquid (ink) ejection can be achieved,
More preferred. This pulse-shaped drive signal is described in US Pat. No. 4,463,359.

The one described in the specification of the same No. 4345262 is suitable. Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

The configuration of the recording head includes, in addition to the combination configuration of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, a heat acting section. The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose configurations in which the wafer is placed in a bending region. In addition, Japanese Patent Application Laid-Open No. 1989-5 discloses a configuration in which a common slit is used as a discharge part of a plurality of electrothermal converters.
No. 9-123670 and Japanese Patent Application Laid-Open No. 59/1989 which discloses a configuration in which a discharge portion is made to correspond to an opening that absorbs pressure waves of thermal energy.
The effects of the present invention are also effective even if the structure is based on the publication No.-138461. That is, regardless of the form of the recording head, according to the present invention, recording can be performed reliably and efficiently.

Furthermore, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by a recording apparatus.

Such a recording head may have either a configuration in which the length is satisfied by a combination of a plurality of recording heads, or a configuration as a single recording head formed integrally.

In addition, even with the serial type shown above, the recording head is fixed to the device body, or by being attached to the device body, electrical connection to the device body and ink supply from the device body are possible. The present invention is also effective when using a replaceable chip type recording head or a cartridge type recording head in which an ink tank is integrally provided in the recording head itself.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus, to the present invention, because the effects of the present invention can be further stabilized. Specifically, these include capping means for the recording head, cleaning means, pressure or suction means, preheating means using an electrothermal transducer or another heating element, or a combination thereof; It is also effective to perform a preliminary ejection mode in which ejection is performed separately from printing in order to perform stable printing.

In addition, regarding the type and number of recording heads installed, for example, in addition to one type that corresponds to single-color ink, there is also a plurality of recording heads that correspond to multiple inks with different recording colors and densities. It may be something that can be done. That is, for example, the recording mode of the recording apparatus is not limited to a recording mode for only a mainstream color such as black, but may also be a recording mode in which the recording head is configured integrally or in a combination of multiple colors, The present invention is also extremely effective for devices equipped with at least one full color by color mixture.

Additionally, in the embodiments of the present invention described above,
Although ink is described as a liquid, it is an ink that solidifies at room temperature or below, but softens or liquefies at room temperature, or in an inkjet method, the ink itself is
Generally, the temperature is adjusted within the range of 0°C or more and 70°C or less so that the viscosity of the ink is within the stable ejection range, so even if the ink is in a liquid state when the recording signal is applied. Bye. In addition, the temperature increase caused by thermal energy can be actively prevented by using the energy to change the state of the ink from a solid state to a liquid state, or ink that solidifies when left standing is used to prevent ink evaporation. In any case, the ink is liquefied by applying thermal energy in accordance with the recording signal, and the liquid ink is ejected, or the ink has already begun to solidify by the time it reaches the recording medium. The present invention is also applicable when using ink that is liquefied only by energy. The ink used in this case is
Publication No. 4-56847 or JP-A-60-71260
As described in the above publication, the porous sheet may be held in a liquid or solid state in the recesses or through-holes of the porous sheet, facing the electrothermal converter. In the present invention, the most effective method for each of the above-mentioned inks is to implement the above-mentioned film boiling method.

Additionally, in addition to being used as an image output terminal for information processing equipment such as a computer, the inkjet recording apparatus of the present invention may take the form of a copying device combined with a reader or the like, or a facsimile device having a transmitting/receiving function. It may also be something.

[Effects of the Invention] As is clear from the above description, according to the present invention, correction data regarding the recording characteristics of the attached recording head is selected from among a plurality of correction data based on selection data possessed by the recording head. This correction data is used to correct the printing characteristics of the printing head.

As a result, the head can be corrected using correction data suitable for the recording head that is always attached without complicating the configuration or operation for correction, and density unevenness can be reduced.

[Brief explanation of drawings]

1A and 1B are a partial detailed view and an overall perspective view, respectively, of an inkjet recording device according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing an example of recording performed by the above device. , FIG. 3 is a block diagram mainly showing the configuration of the image processing section configured in the apparatus of this example, FIG. 4 is a block diagram showing details of the head correction circuit shown in FIG. 3, and FIG. 5 ( A) to (P) are the RO shown in Fig. 4, respectively.
7 is a diagram showing correction pattern data stored in M. FIG. 102... Ink tank, 106... Recording head chip, 120... EPROM, 208... Head correction circuit, 301.302... ROM. 303...Switching circuit. Diagram (A) Shuyoushoku Diagram Diagram Ward

Claims (1)

[Scope of Claims] 1) A recording head in which a plurality of recording elements are arranged for recording on a recording medium, wherein a plurality of correction data are used to correct the density of recording by the plurality of recording elements. A recording apparatus that performs recording using a recording head having a selection data storage means storing selection data for selecting from among the correction data, the correction data storage means storing the plurality of correction data, and the selection data of the recording head. Correction data is selected from among a plurality of correction data stored in the correction data storage means based on selection data stored in the storage means, and recording by the plurality of recording elements is corrected based on the selected correction data. A recording device characterized by comprising means and. 2) In a recording apparatus that performs recording using a recording head in which a plurality of recording elements are arranged for recording on a recording medium, a correction data storage means that stores correction data related to recording of the plurality of recording elements in the recording head. and head data storage means that stores selection data for selecting correction data for the recording head from among a plurality of correction data and life data for the recording head is installed, so that the selected data can be read out. the correction data is selected from among the plurality of correction data stored in the correction data storage means based on the read selection data, and the recording by the plurality of recording elements is corrected based on the selected correction data. A recording device comprising: a correction means for correcting; and a recording device. 3) The recording head has an electrothermal conversion element constituting the recording means, and the heat generated by the electrothermal conversion element causes film boiling in the ink, and as bubbles grow due to the film boiling. Claim 1 characterized in that ink is ejected.
Or the recording device according to 2. 4) The recording apparatus according to claim 3, wherein the recording head is constructed integrally with an ink tank. 5) Arranging a plurality of recording elements for recording on a recording medium and storing selection data for selecting correction data from among the plurality of correction data for correcting the density of recording by the plurality of recording elements. 1. A recording head comprising selected data storage means. 6) The recording head has an electrothermal conversion element constituting the recording means, and the heat generated by the electrothermal conversion element causes film boiling in the ink, and as bubbles grow due to the film boiling. Claim 5 characterized in that ink is ejected.
The recording head described in . 7) The recording head according to claim 6, wherein the recording head is configured integrally with an ink tank.