JPH0939247A - Ink jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To be able to record at a high image quality and quality level by freely driving a plurality of discharge energy generating elements disposed at respective liquid passages in a circuit configuration of the minimum limit. SOLUTION: The ink jet recording head comprises m pieces of ink discharge energy generating elements (electrothermal converters) 3L, 3S capable of generating different energy amounts from each other in respective liquid passages, and n pieces of ink discharge ports capable of selectively discharging ink droplets of large or small size according to the combination drive. The head further comprises heat enable terminals 6L, 6S for individually driving the elements 3L, 3S, an n-bit shift register 10 for transferring a drive signal for driving the energy generating elements, and m pieces of n-bit latch circuits 8L, 8S for temporarily storing m pieces of the respective drive signals from the register 10.

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 head, and more specifically, it has a plurality of ejection energy generating elements for each liquid passage, and the ejection amount can be controlled by independent driving of individual elements or combination driving of a plurality of elements. The present invention relates to an inkjet recording head that can be different.

[0002]

2. Description of the Related Art Conventionally, one ejection energy generating element is provided for each liquid path corresponding to one ink ejection port, and the ejection energy generating element is selectively driven according to a recording signal to select among a plurality of ink ejection ports. There is known an ink jet recording apparatus that ejects ink from a corresponding ink ejection port to perform recording. In addition, many proposals have been made or put into practical use for changing the ink ejection amount in order to embody gradation expression for a recorded image. Among them, as shown in FIG. Multiple (two large and small in this example)
The ink jet recording head provided with the ejection energy generating element can change the ink ejection amount with a relatively compact structure.

In FIG. 4, 1 is an ink ejection port, 2 is a liquid channel through which ink ejected from each ink ejection port 1 is guided, and 3L and 3S are ink ejection energy generating elements arranged for each liquid channel 2. (In the case of this example, 3L is an electrothermal converter for ejecting a large ink droplet, and 3S is an electrothermal converter for ejecting a small ink droplet. The electrothermal converters 3L and 3S are wired (not shown) so that they can be driven individually or simultaneously.

Further, FIG. 5 shows a heating element driving circuit configuration of a recording head in which a total of 64 electrothermal converters (hereinafter referred to as heating elements) 3 are provided for each liquid passage 2. In the following, for each of the heating elements 3, R ₁ , R
₂ , R ₃ , ..., R ₆₄ are assigned individual reference numerals. V _H
Is a common electrode terminal for supplying power to each heating element 3, 4 is a driver consisting of 64 bits for driving the heating element 3,
Reference numeral 5 is an AND gate (group) for individually driving each heating element, 6 is a heat enable terminal (ENB), and 7 is 3
Two block enable input terminals (ENB1, ENB
2, ENB3) and eight block selection output terminals (B
, B2, ..., B8).

Reference numeral 8 is a 64-bit latch circuit, 9 is a latch terminal (LATCH), and 10 is a 64-bit shift register. The latch circuit 8 has a latch terminal 9
And the respective signals from the reset terminal RESET,
The shift register 10 has terminals CLK and DAT.
A clock signal and a data signal are supplied from A, respectively. The recording operation by selectively driving the heating element 3 in the recording head having such a circuit configuration is known, and therefore its description is omitted, but various recording modes,
For example, it is also possible to control so that reciprocal recording is possible.

[0006]

[Problems to be solved by the invention] However,
While it is demanded as a recording apparatus to express a complicated image of higher image quality and higher resolution, various difficulties are involved in further increasing the array density of ink ejection ports with the same size. Therefore, as described above, a technique has been developed for ejecting ink droplets of different sizes by providing a plurality of ejection energy generating elements, for example, heating elements, for each liquid path. In order to configure the drive circuit of the recording head so as to be compatible with the recording mode of, the ink ejection port 1 and the liquid passage 2 of 64 are provided, and m heat generating elements 3 are provided in each liquid passage 2. In this case, the shift register 10 needs to have 64 × m bits.

An object of the present invention is to solve such a problem by the conventional technique, and to further improve the arrangement density of the ink discharge ports and the liquid passages, a plurality of discharges arranged for each liquid passage with a minimum circuit configuration. An object of the present invention is to provide an ink jet recording head capable of freely driving an energy generating element and capable of recording with high image quality and high quality.

[0008]

In order to achieve such an object, the present invention has m ink ejection energy generation elements capable of generating different amounts of energy in respective liquid paths, and the m number of the ink ejection energy generation elements are provided. In the ink jet recording head having n ink ejection ports capable of selectively ejecting large and small ink droplets from the liquid path by individually or in combination driving the ink ejection energy generation elements, A drive enable terminal for supplying a signal for driving the ink discharge energy generating element, an n-bit shift register circuit for transferring the drive signal corresponding to the presence or absence of the drive signal for driving the ink ejection energy generating element, and the shift The drive signals from the register circuit can be temporarily stored in m individual ink ejection energy generating elements, each of which is composed of m bits of n bits. It is characterized in that it has and a latch circuit.

According to the present invention, the ink ejection energy generating element disposed in the liquid passage through the drive enable terminal is connected to the ink ejection energy generating element.
Supplying an individual enable signal and n according to the data
The signal input to the shift register circuit composed of bits is input to each latch circuit that stores m individually,
By outputting m individually via the latch circuit, m ink ejection energy generating elements can be independently driven for each liquid path, and ink droplets of different sizes can be ejected from n ink ejection ports. It is possible to perform high-quality recording by selectively ejecting from the above.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The embodiments described below according to the present invention have, for example, a plurality of electrothermal conversion elements as a plurality of ink ejection energy generating elements in each liquid path. The present invention relates to drive control of an inkjet recording head that performs recording by selectively ejecting ink from a plurality of ink ejection ports by driving individually or in combination.

Embodiments of the present invention will be described below in detail and specifically with reference to the drawings.

FIG. 1 shows a circuit configuration example for driving a heating element of an ink jet recording head according to the present invention. In this example, the number (m) of the ejection elements including the ink ejection ports 1 and the liquid paths 2 is 64, and the number (n) of the heating elements 3 arranged in each liquid path 2 is 2. , R ₁ , R ₂ ,
R ₃ , ..., R ₆₄ are the larger heating elements (called large heating elements)
The individual codes of 3L, r ₁ , r ₂ , r ₃ , ..., R ₆₄ are the individual codes of the smaller heating element (called a small heating element) 3S.
Therefore, R ₁ and r ₁ , R ₂ and r ₂ , ..., R ₆₄ and r ₆₄ are arranged in the same liquid path 2 as shown in FIG.

Further, in FIG. 1, 14 is a heating element 3L,
A heat driver having a total number of 3S equal to 128, 6L and 6S are heat enable terminals, of which terminal 6L is a heat enable terminal for a large heating element and terminal 6S is a heat enable terminal for a small heating element. 8L and 8S are 64-bit latch circuits for large heating elements and small heating elements, and 9L and 9S are input terminals thereof. Other configurations are the same as those shown in FIG. The circuit shown in FIG. 1 is arranged on the substrate 11 (see FIG. 2).

FIG. 2 shows the wiring state of the common electrode 12 to the large heating element 3L and the small heating element 3S arranged on the heating substrate 11 and the individual drive electrodes 13 and 14 to these heating elements 3L and 3S. Thus, the large heating element 3L and the small heating element 3
S is electrically connected to the common electrode 12 provided in the lower layer of the heat substrate 11 through the through hole 15,
The individual drive electrodes 13, 14 and the large heating element 3L and the small heating element 3S are formed on the surface of the heat substrate 11 by a known film forming technique.

Next, the drive operation of the print head drive circuit having such a structure will be described with reference to the timing chart of FIG.

First, the power source V _H is supplied to the large heating element 3L and the small heating element 3S via the common electrode 12 to enable them. The output from each AND gate 5 selectively drives each of the 128 drivers 14 to drive the large heating element 3 and / or the small heating element 3S. First of all, reset terminal RES
As shown in (A) from ET, a reset signal is input to the first latch circuit 8L and the second latch circuit 8S to reset. Then, the serial data D1 for driving the large heating element 3L and the small heating element 3S processed based on the image data.
As shown in (C), the shift register circuit 1 is made to match the driving serial data D2 with the clock signal shown in (B).
It makes it take in 0 sequentially. Further, the latch signals shown in (D) and (E) are output from the terminals 9L and 9S to the first latch circuit 8L and the second latch circuit 8S, respectively,
The fetched data D1 and D2 are latched by the first latch circuit 8L and the second latch circuit 8S, respectively.

Also in this example, a plurality of heating elements 3L,
In each of 3S, when these are driven simultaneously, a large current flows, which is not practical. Therefore, the block selection circuit 7 causes the heating elements 3L and 3S to both block B1 to B3.
It is designed to be distributed and driven separately for each of the eight. Therefore, BL is used as a block enable terminal for selecting which block.
Three of KENB1, BLKENB2 and BLKENB3 are provided, and from these terminals (F), (G),
A pulse signal as shown in (H) is output, and the drive block signals B1 to B1 are generated by combining two pulse signals.
B8 is output from the corresponding terminal of the block selection circuit 7 as shown in (I).

Therefore, in the above output state, the heat enable terminals (HTENB1) 6L and (HTEN)
B2) By outputting the heat enable signal as shown in (J) and (K) from 6S, the AND gate 5 outputs the heat enable signal, the drive block signal, and the data output through the latch circuits 8L and 8S. It is possible to eject a plurality of large and small types of ink ejection amounts as ink droplets by a logical product with the signal.

In the embodiment described above, the number m of discharge energy generating elements (heating elements) arranged in one liquid passage is 2,
Although the case where the number n of ink ejection ports is 64 has been described,
Needless to say, the above numbers m and n are not limited thereto, and the larger the number is, the more remarkable the effect of the present invention becomes.

Further, in the above-described embodiment, the case where the electrothermal converter (heating element) is used as the ink ejection energy generating element has been described, but the ink ejecting energy generating element is not limited to the electrothermal converting element, and for example, piezoelectric. The present invention can be widely applied to ink jet recording heads in which other forms such as elements are used.

[0021]

As described above, according to the present invention, m ink ejection energy generating elements capable of generating different energy amounts are provided in each liquid path, and the m ink ejection elements are ejected. In an ink jet recording head having n ink ejection ports capable of selectively ejecting large and small ink droplets from the liquid path by individually or in combination driving energy generating elements, the ink ejecting energy generating elements are individually driven by m. From the shift register circuit, a drive enable terminal for supplying a drive signal, an n-bit shift register circuit for transferring the drive signal corresponding to the presence or absence of the drive signal for driving the ink ejection energy generating element, Drive signals for the ink ejection energy generating elements can be temporarily stored individually in m units, and m latch circuits each consisting of n bits. Since it is provided, it is possible to achieve high-quality image recording with a simple structure without increasing the array density of the ink ejection ports for improving the image quality and suppressing the expansion of the circuit for driving the ejection energy generating elements. It has become possible. Further, the size and speed of the ejected ink droplets can be freely selected by making it possible to individually control the driving of the plurality of ejection energy generating elements that generate different amounts of energy.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an example of a circuit configuration for driving a heating element according to the present invention.

FIG. 2 is a wiring diagram near a heating element according to the present invention.

FIG. 3 is a timing chart showing the timing of generating a heating element driving signal according to the present invention with waveforms (A) to (K).

FIG. 4 is a perspective view showing a heating element arrangement on a recording head substrate applied to the present invention in a see-through form.

FIG. 5 is a circuit configuration diagram for driving a heating element according to a conventional example.

[Explanation of symbols]

1 Ink ejection port 2 Liquid path 3, 3L, 3S Ink ejection energy generating element (electrothermal converter, heating element) 4, 14 Driver 5 AND gate 6, 6L, 6S Heat enable terminal 7 Block enable input terminal 8L, 8S Latch Circuit 10 Shift register circuit 11 Heat substrate 12 Common electrode 13, 14 Individual drive electrode 15 Through holes R ₁ , R ₂ , ..., R ₆₄ Individual reference symbols r ₁ , r ₂ , ..., R _{64 of} small heating element Individual code

Claims (3)

[Claims] 1. An m ink ejection energy generating element capable of generating different energy amounts is provided in each liquid passage, and the m ink ejecting energy generating elements are driven individually or in combination from the liquid passage. In an ink jet recording head having n ink ejection ports capable of selectively ejecting large and small ink droplets, a drive enable terminal for supplying a signal for individually driving the ink ejection energy generating elements, and the ink An n-bit shift register circuit for transferring the drive signal corresponding to the presence / absence of a drive signal for driving the ejection energy generation element, and a drive signal from the shift register circuit for each m of the ink ejection energy generation element. N which can be temporarily stored in
An ink jet recording head, comprising: m latch circuits composed of bits. 2. The ink jet recording head according to claim 1, wherein the number of drive enable terminals is m. 3. The ink ejection energy generating element is an electrothermal converter that generates thermal energy that causes bubbles in the liquid path to generate a pressure that ejects ink droplets. 1. The inkjet recording head according to 1 or 2.