JP2001096772A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a sharp image making non-jetting inconspicuous even if a nozzle causing non-jetting is present in a plurality of the nozzles provided to an ink jet head. SOLUTION: In an ink jet recording apparatus having multi-nozzle heads at every color components of cyan 8, magenta 9, yellow 10 and black 11, the data related to the position of a nozzle of a non-jetting state among the nozzles of a head of black ink is stored and a signal for recording corresponding to each color component is outputted. In this constitution, the signal corresponding to the position of the nozzle of the non-jetting state of the head of black ink is not outputted and the signal corresponding to the nozzle of the head of other color ink corresponding to the position of the nozzle of the non-jetting state is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for performing color recording using a plurality of multi-nozzle heads having a plurality of nozzles.

[0002]

2. Description of the Related Art Conventionally, in a color copying apparatus using an ink jet recording apparatus for performing color recording with a plurality of multi-nozzle heads, an original to be copied is read by a sensor and the obtained red (R), green (G) and Each signal of blue (B) is converted into each component of cyan (C), magenta (M), yellow (Y) and black (BK) by a masking table, and each converted signal is turned on / off of each nozzle. Binarization was performed so as to be an OFF signal, and color copying was performed.

[0003]

However, in the above conventional example, when a non-ejection portion occurs due to clogging or other causes in the BK nozzle, the recording operation is performed as a whole without ejecting the corresponding nozzle. For this reason, in the formed copied image, a portion where recording is not performed is present as if a single line is drawn, and an image with poor finish is output.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet recording apparatus capable of forming a clear image even when there are non-discharge nozzles among black nozzles.

[0005]

In order to achieve the above object, an ink jet recording apparatus according to the present invention uses a plurality of ink jet heads having a plurality of nozzles corresponding to a plurality of different color inks, respectively. In an ink jet recording apparatus that performs recording by discharging ink from nozzles of the plurality of ink jet heads in response to discharge signals corresponding to nozzles, a plurality of ink jet heads that discharge ink of a predetermined color are provided on the ink jet head. Storage means for storing information relating to the position of a non-ejected nozzle among the nozzles; and an output for outputting a signal for recording corresponding to each of the plurality of ink jet heads corresponding to each of the plurality of colors. Means, based on information stored in said storage means. Does not output a signal corresponding to the position of the nozzle in the non-ejection state of the inkjet head corresponding to the ink of the predetermined color, and outputs a signal corresponding to the ink of a color other than the predetermined color. And output means for changing and outputting a nozzle signal corresponding to the position of the nozzle in the non-ejection state of the predetermined color.

Here, the ink jet recording apparatus of the present invention includes reading means for reading a document image, and can copy and record the document image read by the reading means. Furthermore, preferably, the inkjet head is:
Air bubbles are generated in the ink using thermal energy, and the ink is ejected from the nozzles based on the generation of the air bubbles.

[0007]

According to the present invention, in an ink jet recording apparatus using a multi-nozzle head having a plurality of nozzles corresponding to each of a plurality of different colors, non-discharge of a plurality of nozzles of an ink jet for discharging ink of a predetermined color is performed. In the configuration in which information on the position of the nozzle where the ejection has occurred is stored and a signal for recording corresponding to each of the plurality of nozzles of the plurality of inkjet heads is output, a signal corresponding to the position of the nozzle in the non-ejection state is output. Without performing, a specific nozzle among a plurality of nozzles provided in the inkjet head corresponding to the predetermined color is configured to output the signal corresponding to the nozzle corresponding to the ink other than the predetermined color. Even if a non-discharge occurs, the non-discharge is not noticeable without adversely affecting the formed image. It is possible.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an outline of a copying apparatus to which an ink jet recording apparatus of the present invention is applied. In FIG. 1, reference numeral 1 denotes a document to be copied, 2 denotes a light source for reading the document, 3 denotes a sensor for reading the document, and 4 denotes an output signal of a sensor for reading the document. An A / D converter 5 for converting an analog signal into a multi-valued R, G, B digital signal is a component 5 of the multi-valued R, G, B digital signal for recording ink. . A masking table for converting C, M, Y, and BK; 6, a binarizing device for converting the converted multi-valued C, M, Y, and BK signals into binary signals; A recording control device for driving and controlling each of the multi-nozzle heads based on the binarized C, M, Y, and BK signals, 8 is a cyan multi-nozzle head, and 9 is a magenta multi-nozzle head. , 10 is a yellow multi-nozzle head, 11 is a black multi-nozzle head, and 12 is C, M, Y, BK for recording.
An arithmetic unit 13 for performing arithmetic operations such as various comparisons on each of the signals, and a storage unit 13 for storing data and the like used by the arithmetic unit 12 for the arithmetic operation. The operation will be described with reference to the drawings.

A document 1 to be copied is read by a sensor 3 by a light source 2 and an output signal of the sensor, which is an analog signal, is converted into an R, G, B digital signal by an A / D converter 4. The converted R, G, B signals are separated into multi-valued digital signals by a masking table 5 in order to convert them into C, M, Y, BK for recording. further,
The C / M / Y / BK multi-valued digital signal is converted into binary digital data for recording control by the binarization device 6, and the C, M, Y and BK binary digital data are used. The recording control device 7 drives and controls each multi-nozzle head to form a copy image.

FIG. 2 shows the state of the recording dots when all the BK multi-nozzle heads 11 perform an ejection operation. FIG. 2 shows a state where the m-th nozzle is not ejected among the n nozzles. If the presence of a non-ejection nozzle is confirmed during a copying operation or during inspection of the apparatus, it is possible to know the number of the non-ejection nozzle by scanning an image formed by, for example, a photo sensor. Then, the non-ejection nozzle is stored in the storage device 13.
Can be stored.

When there is a non-ejection nozzle as shown in FIG. 2, control is actually performed as shown in FIG. That is, since the number of the non-ejection nozzle among the BK nozzles is stored in the storage device 13 in advance, it is determined whether or not the ejection signal for each BK nozzle corresponds to the stored non-ejection nozzle. The determination is made by the arithmetic unit 12. Then, as shown in FIG. 3, when the ejection signal 1 is given to the m-th BK nozzle that is not ejected, that is, when ejection is ON, the arithmetic unit notifies the recording control device 7 that the corresponding signal is inappropriate. And the other C, M,
The signal of each m-th nozzle of Y is set to 0, that is, the ejection OF
The discharge is performed from the state of F to 1, that is, in the state of the discharge ON. As a result, for the m-th nozzle, black is generated by mixing C, M, and Y instead of BK, and printing is performed. As a result, the BK that stands out when there is a non-ejection portion
Even if a discharge nozzle exists, an image in which a non-discharge portion is eliminated can be generated by alternative printing using C, M, and Y.

Embodiment 2 FIG. 4 shows another embodiment of the present invention. In the figure, reference numeral 14 denotes a plurality of A / D converters for converting R, G, and B signals obtained by A / D conversion of analog signals obtained by reading an original into C, M, Y, and BK signals for recording. Masking table with a masking factor of 6
Is a binarization device for converting multi-valued C, M, Y, and BK signals into binary values so as to be suitable for ejection from the multi-nozzle head.
A print control device for controlling, 8 is a cyan multi-nozzle head, 9 is a magenta multi-nozzle head, 10 is a yellow multi-nozzle head, 11 is a black multi-nozzle head, and 12 is a comparison for each ejection signal data. Is a storage device that stores in advance which of the C, M, Y, and BK multi-nozzles is a non-ejection nozzle and transfers data to the arithmetic device 12 and the like. . The operation will be described with reference to FIG. If the BK nozzle is not ejected for the portion to be printed, the RGB signals input to the masking table are multi-valued by the masking table according to the ratio of each of the R, G, and B components as shown in FIG. M, Y, B
It is converted into a signal of each component of K. However, the corresponding BK
If the nozzle of No. is not ejected, that is, if a certain nozzle to be converted from R, G, B to C, M, Y, BK matches the nozzle stored in the storage device 13 in advance, the arithmetic unit 13 Convert the masking table used. As a result, as shown in FIG. 5 (b), the R, G, B signals are C, M,
It is converted into a multilevel signal of each component of Y, and BK is set to 0, that is, there is no BK component. The signal converted into C, M, Y, and BK including the non-ejection portion of the nozzle in this manner is binarized by the binarization device 6 to be a signal for ejection, and is recorded by the recording control device 7 into C, M, Y. The M, Y, and BK multi-nozzle heads are driven to perform recording. This allows
In particular, for a BK that affects an image when there is a non-ejection portion, by using conversion from R, G, B to only C, M, and Y, printing without adverse effects even if the BK nozzle has an ejection failure. It can be carried out.

Further, from R, G, B to C, M, Y, BK
By changing the masking table of conversion, C and M
Even if there is a non-ejection portion in the multi-nozzle head, the non-ejection portion can be supplemented with another color by converting it into an approximate color component.

Furthermore, not only from the R, G, B components of the original reading by copying the original, but also from the external input to the copying apparatus, that is, the input of R, G, B or C, M, Y , BK can be similarly performed.

(Others) The present invention includes a means (for example, an electrothermal converter, a laser beam, or the like) for generating thermal energy as energy used for discharging ink, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding the nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

The configuration of the recording head may be a combination of a discharge port, a liquid path, and an electrothermal converter (a linear liquid flow path or a right-angled liquid flow path) as disclosed in the above-mentioned specifications. U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44,558 which disclose a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, 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 on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, even in the case of the serial type as described above, the recording head fixed to the apparatus main body or the electric connection with the apparatus main body or the ink from the apparatus main body by being attached to the apparatus main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.

It is preferable to add ejection recovery means for the recording head, preliminary auxiliary means, and the like as the configuration of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

The type and number of recording heads to be mounted are not limited to those provided only for one color ink, for example, and for a plurality of inks having different recording colors and densities. A plurality may be provided. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature may be used. In general, in the ink jet method, the temperature of the ink itself is adjusted within a range of 30 to 70 degrees to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, the ink may be in a liquid state.
In addition, in order to positively prevent temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or to prevent evaporation of the ink, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start to solidify when reaching the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink is disclosed in JP-A-54-56847 or JP-A-60-712.
As described in Japanese Patent Application Publication No. 60-260, a mode may be adopted in which the liquid sheet or the solid sheet is held as a liquid or solid substance in the concave portion or through hole of the porous sheet so as to face the electrothermal converter.
In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the form of the ink jet recording apparatus of the present invention is not only used as an image output terminal of an information processing apparatus such as a computer, but also for a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function. It may take a form.

[0025]

As described above, according to the present invention,
The image corresponding to the non-ejection nozzle portion of the multi-nozzle head corresponding to a predetermined color is supplemented by using the nozzle of the same portion of the multi-nozzle head of another color by discharging from the nozzle of another color, thereby forming an image. A clean recording can be performed without being disturbed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an outline of a copying apparatus embodying the present invention.

FIG. 2 is a diagram illustrating a printing state of a BK nozzle head.

FIG. 3 is a diagram illustrating a method of discharging another nozzle with respect to BK nozzle printing illustrated in FIG. 2;

FIG. 4 is a block diagram showing an outline of another embodiment of the copying apparatus.

FIG. 5 is a diagram showing a change of a masking table in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Original to be copied 2 Light source 3 Reading sensor 4 A / D converter 5 Masking table 6 Binarization device 7 Printing control device 8 Cyan multi-nozzle head 9 Magenta multi-nozzle head 10 Yellow multi-nozzle head 11 Black multi-nozzle Head 12 Arithmetic unit 13 Storage unit 14 Masking table

Claims (10)

[Claims] An ink jet head having a plurality of nozzles is used corresponding to each of a plurality of different color inks, and ink is ejected from the nozzles of the plurality of ink jet heads in accordance with an ejection signal corresponding to each nozzle. An ink jet recording apparatus that performs recording by using an ink jet head that discharges ink of a predetermined color; and a storage unit that stores information regarding the position of a non-ejected nozzle among a plurality of nozzles provided in the ink jet head; Output means for outputting a signal for recording corresponding to each of the plurality of nozzles of the plurality of inkjet heads, wherein the predetermined color is determined based on information stored in the storage means. Position of the nozzle in the non-ejection state of the inkjet head corresponding to Without outputting a signal corresponding to the predetermined color, and among a plurality of nozzles of the ink jet head corresponding to inks other than the predetermined color, a signal of a nozzle corresponding to the position of the nozzle in the non-ejection state of the predetermined color. And an output unit for changing and outputting the output. 2. The masking means according to claim 1, wherein said output means converts a primary color signal comprising a plurality of specific colors into a signal corresponding to each of a plurality of inks corresponding to said plurality of ink jet heads according to a masking table and outputs the signal. The ink jet recording apparatus according to claim 1, wherein: 3. The masking means converts the primary color signal corresponding to the position of the nozzle in the non-ejection state to a signal corresponding to ink other than the predetermined color, based on information stored in the storage means. 3. The ink jet recording apparatus according to claim 2, wherein the output is converted. 4. A masking table for converting the primary color signal corresponding to the position of the nozzle in the non-ejection state, and converting the primary color signal corresponding to a position other than the position of the nozzle in the non-ejection state. 4. The method according to claim 3, wherein the masking table is different from the masking table.
3. The ink jet recording apparatus according to claim 1. 5. The apparatus according to claim 2, wherein the masking means converts the multi-valued primary color signal into a multi-valued signal corresponding to each of the plurality of ink colors and outputs the converted signal. An inkjet recording apparatus according to any one of the above. 6. The ink jet recording apparatus according to claim 5, further comprising a binarizing unit for binarizing signals corresponding to the colors of the plurality of inks output from the masking unit. 7. The primary color signal is a signal corresponding to three primary colors of R, G, and B, and the colors of a plurality of inks corresponding to the plurality of inkjet heads are cyan, magenta, yellow, and black. The ink jet recording apparatus according to any one of claims 2 to 6, wherein: 8. The ink jet recording apparatus according to claim 1, wherein the predetermined color is black. 9. The ink jet recording apparatus according to claim 1, further comprising a reading unit for reading a document image, and performing copy recording of the document image read by the reading unit. 10. The ink-jet head according to claim 1, wherein bubbles are generated in the ink by using thermal energy, and the ink is ejected from the nozzles based on the generation of the bubbles. 3. The ink jet recording apparatus according to claim 1.