JPH01114447A - Ink-jet recorder - Google Patents

Abstract

PURPOSE:To produce a high-quality image without color smearing by converting the original color information to color ink information based on a subtractive process in such a manner that the ink output for each color in mixing two or more colors is limited less than the ink output for a single-color print. CONSTITUTION:A recording head unit 90 for color imaging has an array of four respective heads 9A, 9B, 9C, and 9D for cyan, magenta, yellow, and black, arranged along the scanning direction. This head unit is adapted to print a given pattern of ink dots on a recording medium 1 placed in front of it. Original color information is converted to color ink information based on a subtractive process. In mixing two or more colors, the ink output for each color is limited less than the ink output for a single-color print. Thus, the limit of ink absorption of paper will not be exceeded, and a high-quality color image can be obtained without smearing in a mixed-color made.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to an inkjet recording device, and particularly to a color inkjet recording device that performs color printing.

[Prior Art] As shown in FIG. 2, red (hereinafter referred to as R), green (hereinafter referred to as G), and blue (hereinafter referred to as B) are complementary colors to Y, M, and C. Therefore, as shown in FIG. 3, in the case of a color recording apparatus, R is formed by overlapping yellow (hereinafter referred to as Y) and magenta (hereinafter referred to as M). Similarly, G is formed by overlapping Y and cyan (hereinafter referred to as C), and B is formed by overlapping C and M. Also,
When the three MMC colors are superimposed, it becomes black, so in principle, the three primary colors are sufficient, but the black produced by mixing the three colors looks muddy. For this reason, color recording devices that use black ink are common.

[Problems to be Solved by the Invention] In the inkjet recording method, paper absorbs ink to form figures, characters, and symbols.

However, there is a limit to the ink absorption capacity of paper. Therefore, when shapes, characters, and symbols are formed by overlapping colors as in a color printer, the amount of ink on paper differs when printing with one color ink and when printing with two color inks overlapping. Therefore, if the ink absorption capacity of the paper exceeds the limit, the ink will be absorbed and the image quality will be significantly degraded.

The object of the present invention is to solve the above-mentioned deficiencies, for example, two-color superimposition color mixing mode 1. It is an object of the present invention to provide a color inkjet recording device that can form stain-free and high-quality colors even in the kidneys.

In more detail, ■ In the color inkjet recording system, the amount of ink ejected in the mixed color mode of two or more colors is varied, and the amount of ink on the paper is controlled to produce the specified red (hereinafter referred to as R) and green (
A color inkjet recording device that forms the color G), blue (B); A color inkjet recording device that distributes the amount of ink ejected in mixed color mode to the same amount as the amount of ink for one-color printing; The amount of ink ejected in the mixed color mode is controlled by the applied voltage in a color inkjet recording device.The amount of ink ejected in the mixed color mode is controlled by the width of the applied pulse in the color inkjet recording device described above.

Means for Solving Problem E] The invention provides a conversion means for converting color information into color ink information based on subtractive color mixing, and a method for discharging each color ink when two or more color inks are mixed based on the conversion result of the conversion means. (2) means for limiting the amount of ink to be less than the amount when one color ink is ejected;

[Function] According to the present invention, the amount of ink ejected in the mixed color mode of two or more colors is varied, and the amount of ink relative to paper is controlled to make the amount of ink ejected the same as the amount of ink for one-color printing.

[Example 1] The present invention will be specifically described below with reference to the drawings. FIG. 1 shows an inkjet type color inkjet recording apparatus suitable for carrying out the present invention.

In FIG. 1, a recording medium 1 such as a paper or a plastic sheet is supported by conveyance rollers 2.3 consisting of a pair of upper and lower rollers, and is moved by a conveyance roller 2 driven by a sheet feed motor 4 at an arrow mark 2.3. conveyed in the direction. A pair of guide shafts 5 are provided in front of and parallel to the conveyor rollers 2 and 3. That is, a carriage 6 is driven by a carriage motor 7 along the guide shafts.
is reciprocated in the direction of arrow B via the wire 8.

A recording head unit 90, which is an inkjet head, is mounted on the carriage 6.

The recording head unit 90 is for creating color images, and includes four recording heads arranged in the scanning direction and recording with cyan, magenta, yellow, and black inks, that is, 9A, 9B, 9G, and 9D. It has become. A recording section in which ink ejection ports are arranged is provided on the front surface of each recording head, that is, at a location facing the recording medium 1 at a predetermined interval (for example, 0.8 mm). That is, ink ejection ports are formed at a predetermined pitch on the surface of the recording unit facing the recording medium l, and the electrothermal transducer, heating resistor, etc. of each ink ejection port is driven (electrified heating) based on the recording information. ) to foam the ink, and the expansion pressure forms flying ink droplets, and recording is performed while the ink dots are attached to the recording medium 1 in a predetermined pattern.

Each recording head is equipped with a circuit board for a drive circuit (heat driver) for driving the recording head as described above.

In FIG. 1, the control circuit (CPU) of the recording apparatus and the ROM, RAM, etc. attached thereto are formed on a control board, and this control circuit receives command signals and data from a host machine 14 such as a computer. Receive the signal (recorded information),
Based on this, a heat voltage is applied to each of the recording heads 9A to 9D via the heat driver as well as various motors and the like.

The operation panel 160 attached to the exterior case (not shown) of the recording device has online/offline off 1 & e key 1.
68, line foot key 160. In addition to keys such as the form feed key 16G and the recording mode switch key 16D, there are also several alarm lamps 16E and power lamps 16F.
Warning lamps are installed.

FIG. 4 is a block diagram showing a control system of the inkjet recording apparatus of FIG. 1.

In Figure 4, CPU (microprocessor) 2
1 is connected to a host machine 14 such as a computer via an interface 22, and receives command signals (commands) and recorded information signals read into a data memory 23 from the host machine, as well as ROMs such as a program memory 24 and a working memory 25. The recording operation is controlled based on programs stored in, for example, those shown in FIGS. 5 and 6.

The CPt 121 controls the carriage motor 7 (FIG. 1) and the sheet feed motor 4 (FIG. 1) via the output boat 26 and motor driver 27, and also controls the head based on recorded information stored in the data memory 23. The recording heads 9A to 9D are controlled via a circuit 29.

The number 30 in FIG. 4 is a sheet sensor that detects whether or not the recording medium 1 exists between the conveyance rollers 2 and 3 (FIG. 1), and sends a detection signal to the CP+121 via the manual boat 31. is transmitted.

Each operation key 16A to 16 on the operation panel 160 described above
The output from D (FIG. 1) is transferred to C via a human-powered boat 32.
The signal is transmitted to the PU 21, and the output boat 3
An electrical signal is supplied via 6.

Reference numeral 33 in FIG. 4 is a dip switch provided on the bottom of the exterior, etc., and its output is transmitted to the CPU 21 via the human-powered boat 34.

In FIG. 4, a logic drive voltage VCC (5V) is supplied from the power supply circuit 28 for operating the control logic circuit.
, various motor drive voltages VM (30V), reset voltage RESET, heat voltage (head voltage) Vl+(25V) for heating the dot forming elements of each recording head.
V) and a backup voltage VD for protecting the recording head are output.

An embodiment will be described below with reference to the flowcharts of FIGS. 5 and 6.

(Fig. 5) After the control unit initial processing (5101) when the power is turned on, C
The PU 21 is in an idling state while monitoring control commands and printing data from the host machine 14 connected to the printer via the interface 22 (sto2
).

In this embodiment, it is assumed that the color bit image settings with the host machine are executed according to the following specifications.

ESCr DAT8L to NGTII IMAGE
It takes the form of DATA.

ESCr indicates a color bit image setting command.

DATA LENGTll (data length) is a 1-byte parameter that indicates the total number of bytes of image data in this command.

The first "n" bytes of image data are red, the next n" bytes of image data are green, and the last "n" bytes of image data are blue.

At 5102, the host machine 14 connected to the printer
When the print data is input manually from 5103, [:
The PU 21 stores data in the receiving RGB buffer provided in the data memory 23 as shown in FIG.

“#” corresponds to a recording dot. The CPU 21 determines whether the reception of specified print data from the host machine 14 is complete (510
Turn around 5102 to 5104 until 4).

When the CPU 21 finishes receiving the specified print data from the host machine 14, in step 5105, the CPU 21 transfers the data in the RGB buffer of the data memory 23 to the YMCBk buffer for printing provided in the data memory 23 using a conversion circuit as shown in FIG. The YMCBk data obtained by conversion (the conversion table is shown in FIG. 8) is stored separately into tl and tl as shown in FIG.

ESCr 08N (DATA LEN) from the above host
GTH) AAH... (RDATA) CCII...
When (G DATA) FO) l... (B DATA) is transmitted, it is stored in the reception buffer as shown in FIG.

When expanding from 80 mouths to YMC[lk, in this example, 16 YMCBk heads 9A to 9D are mounted on the soil of the carriage as shown in Figure 1, so there is a gap between each head and spatula 1 to . CI' to correct the printing interval
When U21 is expanded to YMCBk, 0 is set in advance in the printing interval part.
0 Data is stored manually.

After storing the print data expanded from RGII to YMCBk, the CPt 121 controls the start of printing (S106).

At 5106, the CPt 121 moves the carriage 29 to P.
Driver 2 from output port 26 to move in T input direction
7, the carriage motor 7 is excited in the right direction. Next, at 5107, the control circuit 29 controls the heads 9A to 9D.
Set the print data of tl (print data developed into YMCBk) in . After setting, a prescribed pulse is applied to the head at 510B. The pulse width at this time is as follows:
It is defined by the timer (t1) (5109). Next, in step 5110, the control circuit 29 sends the tl one-color print data (YMCn) developed to the head so as not to mix the two colors.
Set the expanded print data) to k. 5I after set
A prescribed pulse is applied to the head at IOA. The pulse width at this time is defined by the next second timer (t1) (Sll1). After time-up, power to the head is cut off (5112).

At 5113, the recording cycle counter provided in the working 25 is incremented by 1 every time the current is applied. The recording cycle counter determines whether printing is complete (511
4). If the recording cycle counter does not exceed the specified print dot value in 5114, the process returns to 5106;
The operations of 5106 to 5114 are repeated. If the recording cycle counter exceeds the specified print dot value in 5114, the process advances to 5115 and the output port 26° driver 27
The paper feed motor 4 is moved through the paper to feed the paper one line in the direction. With the above steps, printing of one line is completed.

(Figure 6) In this example, 5201 to 5204 are 5101-5204.
Almost the same as 5104, but CPL in 5203
I21 differs only in that data is stored in a receiving 11 GB buffer provided in data memory 23 as shown in FIG. 1O.

The following 5205 differs from 5105 only in that the converted data (YMCBk) is stored separately into tl and Vl+ as shown in FIG. 1O. Also, from the above host
SCr 0811 (DATA LENGTII
) to A11... (R[lAT8)CCII...
・(GDAT8)FOH...When (B DATA) is transmitted, it is stored in the reception buffer as shown in FIG. Note that when developing from nG11 to YMCBk, in this example as well, since the YMCBk heads are mounted on the carriage as shown in FIG. 1, there is a gap between each head. CPt to correct the printing interval.
121 is 0 in advance in the printing interval part when expanding to YMCBk.
0 Data is stored manually.

After storing the print data expanded from RG[l to YMCBk, the CPU 21 controls the start of printing (5206). 5
At 206, the CPU 21 excites the carriage motor 7 in the right direction from the output port 26 via the driver 27 in order to move the carriage 29 in the PT input direction. Next 5
At step 207, all print data (print data expanded into YMCnk) is set in the head by the control circuit 29. After setting, in step 5208, the voltage applied to the head is set. As shown in FIG. 1O, whether to apply a high voltage or a low voltage to [lk, C1M, and Y is set by Ilo of the V11 buffer in the memory 23.

Next, in 5209, a prescribed pulse is applied to each head. The pulse width at this time is defined by the following timer tl (5210). After time-up, power to the head is cut off (5211).

5212-5214 are the same as headings 5112-5114.

In both of the above two examples, by setting the time or applied voltage to a predetermined value, the amount of ink ejected in one recording dot can be made the same as the amount in one packet even when two colors are mixed.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide an inkjet recording apparatus that can perform recording without color bleeding.

[Brief explanation of the drawing]

Figure 1 is a 4'1 perspective view of a bubble jet type inkjet recording apparatus suitable for applying the present invention, Figures 2 and 3 are principle diagrams showing the subtractive color mixing method, and Figure 4 is a diagram of the present recording apparatus. A block diagram of the control system, FIGS. 5 and 6 are flowcharts for implementing the present invention, FIG. 7 is a logic circuit diagram for converting from IIGB to YMCBk,
FIG. 8 is a diagram showing the conversion table, FIG. 9 is a diagram showing an example of buffer information in the first embodiment, and FIG. 1O is a diagram showing an example of buffer information in the second embodiment. 7... Carriage motor, 9... Recording head, 11... Heater, 13... Head drive circuit, 14... Host machine, 21... CPU. , Q BLACK -/ \'OcYAw Figure 3 Moto P1 To is also required (1) Minu χ <! 5 Tunme Sakuzuto also Figure 8

Claims (1)

[Scope of Claims] 1) Conversion means for converting color information into color ink information based on subtractive color mixing, and based on the conversion result of the conversion means, the ejection amount of each color ink when two or more color inks are mixed is adjusted to one color ink. 1. An inkjet recording apparatus comprising: means for limiting the amount to less than the amount at the time of ejection. 2) The inkjet recording apparatus according to claim 1, wherein the limiting means limits the amount of each color ink ejected when two or more color inks are mixed based on information on the voltage value applied to the recording head. . 3) The ink jet recording according to claim 1, wherein the limiting means limits the amount of each color ink ejected when two or more color inks are mixed based on information on the voltage pulse width applied to the recording head. Device.