JPH06155766A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To eliminate the lowering of image quality to be caused by fluctuations in emitting characteristics of inks by providing an emitting drive time control means controlling an emitting drive time for every kind to an ink jet recording apparatus. CONSTITUTION:The electrothermal converters R1-32, R33-64, R65-96, R97-128 in a silicon substrate 11 are provided in order to emit yellow ink, magenta ink, cyan ink and black ink. the 128-bit transistor array in an integrated circuit 12 are divided into dispersion blocks by four blocks corresponding to four signals of BE1, BE2, BE3, BE4 and the respective blocks are successively driven. Signals ENB1-ENB4, signals BE1-BE4, a signal LAT, a signal DATA and a signal CLOCK are supplied to a head from an ink jet recording apparatus. By separately controlling the emitting drive times of respective colors, the irregularity of the emitting characteristics of the respective color inks can be corrected and image quality is enhanced.

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.

[0002]

2. Description of the Related Art Conventionally, the structure of an ink jet recording head is such that an electrothermal transducer array is formed on a silicon substrate,
As a drive circuit for this electrothermal conversion element, a drive integrated circuit substrate is provided outside the silicon substrate, and the connection between the two substrates is made using an electrical connection means such as wire bonding.

FIG. 4 shows a specific example of the recording head. In FIG. 4, 41 is a silicon substrate forming the electrothermal conversion element group. In this conventional example, the electrothermal conversion element group is composed of 128 heating resistors R1 to R128. In addition, this heating resistor is R1-R32, R33-
It is divided into 4 blocks of R64, R65 to R96, R97 to R128, R1 to R32 are yellow and R33 to R33.
64 is magenta, R65-R96 is cyan, R97-R
Reference numeral 128 is divided for the role of ejecting each black ink.

Reference numeral 42 denotes an integrated circuit for driving the electrothermal conversion element group on the silicon substrate 41. In this conventional example, the heating resistor is energized at four timings, and the energization is performed every 4 bits.
That is, it is divided into distributed blocks corresponding to four signals BE1, BE2, BE3, BE4, and when the signal BE1 is selected, the heating resistors R1, R5, R9, ...
125, when BE2 is selected, heating resistors R2, R
6, R10, ... R126, when BE3 is selected, the heating resistors R3, R7, R11 ,.
When BE4 is selected, the heating resistors R4, R8, R12,
...... The so-called distributed drive system in which R128 is driven is adopted. ENB is a signal that controls the time for which the heating resistor is energized. DATA is an image signal, CLOCK is a clock for sending the image signal to the shift register, LA
T is a signal for latching the image signal.

[0005]

However, in the above-mentioned conventional example, since four color inks are simultaneously driven by the same IC and the energizing time of the heating resistor is controlled by one ENB signal, yellow, magenta, Both cyan and black are driven with the same energization time. However, if the inks are different, the ejection amount differs depending on the type of ink during the same energization time, and the ejection amount differs for each color, resulting in a problem that the image quality deteriorates.

The present invention has been made to solve this problem, and it is an object of the present invention to provide an ink jet recording apparatus in which the image quality does not deteriorate due to variations in the ejection characteristics of a plurality of types of ink.

[0007]

In order to achieve the above object, in the present invention, an ink jet recording apparatus is constructed as in the following (1) and (2).

(1) An ink jet recording apparatus for ejecting a plurality of types of ink, which is provided with an ejection drive time control means capable of controlling the ejection drive time for each type of ink.

(2) The ink jet recording apparatus according to the above (1), wherein the ink jet recording apparatus causes a state change in the ink due to heat and ejects the ink based on the state change.

[0010]

With the configurations (1) and (2), the ejection drive time can be controlled according to the ejection characteristics of each type of ink.

[0011]

EXAMPLES The present invention will be described in detail below with reference to examples.

(Embodiment 1) FIG. 1 is a circuit diagram of a head portion of an "ink jet recording apparatus" which is Embodiment 1. In FIG. In the figure, 11 is a silicon substrate on which electrothermal conversion element groups are arranged, and 12 is an integrated circuit for driving the electrothermal conversion element groups. Heating resistors R1 to R12 in the silicon substrate 11
8 are connected to the 128-bit transistor array in the integrated circuit 12 bit by bit. Silicon substrate 11
The electrothermal conversion elements in the inside are the same as those in the conventional example of FIG.
R32 is yellow ink, R33 to R64 is magenta ink, R65 to R96 is cyan ink, R97 to R128.
Is provided for ejecting black ink. The 128-bit transistor array in the integrated circuit 12 is divided into four distributed blocks corresponding to four signals BE1, BE2, BE3, and BE4, and sequentially driven in a distributed manner. LAT, DATA, and CLOCK are the same signals as in the conventional example.

ENB1 to ENB4, BE1 to BE
4, LAT, DATA, and CLOCK signals are supplied to the head from the inkjet recording apparatus main body (not shown).

FIG. 2 shows the timing of drive signals in this embodiment. Referring to FIG. 1, BE1
The signal is active, that is, enabled during Ta time, at which time the heating resistors R1, R5, ... R125 can be energized. The BE2 signal is enabled during Tb, during which the heating resistors R2, R6, ... R126 can be energized. The BE3 signal is enabled during Tc, during which the heating resistors R3, R7, ... R12.
7 can be energized. The BE4 signal is enabled during Td, during which the heating resistors R4, R8, ...
128 can be energized. As described above, each block is divided into four blocks and driven sequentially.

The heating resistors R1 to R32 have ENBs.
The ENB2 signal is supplied to the heating resistors R33 to R64, the ENB3 signal to the heating resistors R65 to R96, and the ENB4 signal to the heating resistors R97 to R128 via the AND gate. That is, ENB1, EN
The B2, ENB3, and ENB4 signals are signals that control the energization time for ejecting yellow, magenta, cyan, and black inks, respectively.

Taking the above Ta as an example, the ENB between Ta
During the time Ta1 when the 1 signal is enabled, the heating resistor corresponding to the nozzle that ejects the yellow ink is energized according to the image signal, and the nozzle is ejected. Further, during the time Ta2 when the ENB2 signal is enabled, the nozzles that eject magenta ink are driven to eject. Similarly, during the time Ta3, the nozzles that eject cyan ink are ejected, and during the time Ta4, the nozzles that eject black ink are ejected.

As described above, since the ejection driving time of each color ink can be controlled separately, it is possible to correct the variation in the ejection characteristics of each color ink and improve the image quality. The insulating substrate 11 and the driving integrated circuit 12 may be integrally formed on the same substrate.

(Second Embodiment) FIG. 3 is a circuit diagram of the head portion of the second embodiment. This embodiment is an example in which a decoder is used for block selection. As shown, there is a silicon substrate 31 in which electrothermal conversion element groups are arranged, and an integrated circuit 32 for driving the heating resistors R1 to R96 in the substrate is connected to the substrate 31. Further, the distributed block is divided into 8 blocks, and the decoder 33 is used for block selection. The signals BE1, BE2 input to this are
A block is selected by decoding the three signals of BE3.
Even if the block selection method changes in this way, ENB1
Since the energization time is controlled for each color by the ENB3 signal, variations in the ejection characteristics of ink of each color can be corrected and the image quality is improved, as in the first embodiment.

Each of the above embodiments is an example of a so-called electric / heat conversion type ink jet recording apparatus in which the ink causes a state change due to heat and ejects the ink based on the state change. The invention is not limited to this, and can be carried out in an appropriate ink jet recording apparatus such as an electromechanical conversion system (piezoelectric type).

Further, although each embodiment corrects the variation in the ejection characteristics of inks of different colors, the invention is not limited to this, and the variation in the ejection characteristics of inks of the same color and different densities is corrected. Can also be carried out.

(Related Art) The present invention provides excellent effects particularly in a recording head and a recording apparatus of a system utilizing thermal energy among ink jet recording systems.

Regarding the typical structure and principle thereof, see, for example, US Pat. Nos. 4,723,129 and 4740.
What is done using the basic principles disclosed in 796 is preferred. 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, liquid (ink)
Applying at least one drive signal to the electrothermal converter arranged corresponding to the sheet or flow path in which is stored, corresponding to the recorded information and causing a rapid temperature rise exceeding nucleate boiling. Is effective because it causes heat energy to be generated in the electrothermal converter to cause film boiling on the heat acting surface of the recording head, and as a result, bubbles can be formed in the liquid (ink) in one-to-one correspondence with this drive signal. . Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable to make the drive signal in the form of a pulse because the growth and shrinkage of the bubbles are immediately and appropriately performed, so that it is possible to discharge the liquid (ink) with excellent responsiveness. This pulse-shaped drive signal is described in US Pat.
Those described in 345262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. U.S. Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
The present invention can be implemented in the configuration disclosed in the specification of No. 459600. In addition, JP-A-59-123670, which discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 59-138431, which discloses a configuration corresponding to the ejection portion.

[0024]

As described above, according to the present invention,
Dispersion in ejection characteristics of a plurality of types of ink can be corrected, and image quality is improved.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a recording head according to a first embodiment.

FIG. 2 is a timing chart of drive signals in the first embodiment.

FIG. 3 is a circuit diagram of a recording head according to a second embodiment.

FIG. 4 is a circuit diagram of a conventional example.

[Explanation of symbols]

 11 Silicon substrate 12 Integrated circuits R1 to R128 Heating resistors

Claims (2)

[Claims] 1. An ink jet recording apparatus for ejecting a plurality of types of ink, comprising an ejection drive time control means capable of controlling the ejection drive time for each type of ink. 2. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus causes a state change in the ink due to heat, and ejects the ink based on the state change.