JPH02289353A - Recorder - Google Patents

Abstract

PURPOSE:To alleviate the deterioration of a recording quality caused by a recording gap while a power demand and a power source capacity are kept small intact as conventional ways and to improve a recording speed by providing a division drive block selection means for making corresponding drive elements drive at a part where the supply of drive signals from a simultaneous drive control means is overlapped. CONSTITUTION:The pulse width of a pulse EI outputted from a simultaneous drive control part 3 in accordance with the output of a counter circuit 2 coincides with two cycles of a clock ECLK, or drive elements are driven every two blocks (the number of division drive blocks is m/2). Each of output signals EO1 - EOm from flip flops 51 - 5m has parts overlapped with the adjacent outputs. At this time, a division drive block selection circuit 1 outputs a signal BEO at a timing coincident with said overlapped part. Namely, at a part where the outputs EO1 and EO2 are overlapped, it outputs a first BEO, and at a part where the outputs EO3 and EO4 are overlapped, it outputs a next BEO. After that, BEOs are outputted in a similar manner. Thus, two blocks can be simultaneously driven. In this manner, the number of division driving blocks is arbitrarily set, thereby a recording gap in a recording image is prevented from occurring.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a recording device, and in particular an inkjet recording device in which a plurality of electrothermal transducer elements for ejecting ink are divided into blocks, and each block has a different The present invention relates to a recording device that is driven based on timing.

[Prior Art] An inkjet recording device as a recording device will be described below. The inkjet recording method is a recording method in which droplets of a recording liquid (hereinafter referred to as ink) are ejected using various methods, and the droplets are attached to a recording medium such as recording paper to perform recording.

Among recording devices that use such a recording method, a device that uses heat as energy to form ejected droplets is suitable for creating a print head with a configuration in which a large number of ejection ports are arranged at high density. An example of this type of inkjet recording device is a type of inkjet recording device.

Inkjet recording devices that use heat as energy for ejecting droplets usually heat the ink to create a displacement in the ink that causes a rapid increase in volume, and this displacement causes ink droplets to be ejected from the ejection orifice. A recording head that has an electrothermal converter that generates heat to heat the ink, and an ink liquid path that communicates with the ejection port and allows the heat from the electrothermal converter to act on the ink. It is equipped with Furthermore, in a recording head having a plurality of ejection ports, a plurality of these electrothermal transducers are also provided correspondingly.

A conventional inkjet recording head having such an electrothermal transducer, especially a plurality of ejection ports corresponding to the recording width of one line as shown in FIG. 6, and therefore a plurality of electrothermal transducers Rl""' In an inkjet recording head in which Ran is arranged, a method is used in which these electrothermal transducers are divided into several blocks (m blocks in FIG. 6) and the electrothermal transducers are driven for each block.

For example, in a circuit as shown in FIG. 6, when driving the timing shown in FIG. 7, the flip-flop 5. ~51. ANDGATE 61-6, s, 7. ~
7. ．． Latch circuit 8. ~8□, and shift register 9
1-9. The electrothermal converter groups corresponding to each of the drive ICs constituted by each of these are sequentially driven as one block.

This block drive method has been used conventionally because the power consumption for driving the inkjet recording head is significantly reduced compared to a method that does not perform block drive.

was there.

Further, when dividing driving is performed for each block, it is conceivable that more recording time is required compared to, for example, driving every plural blocks or all blocks at the same time.

The present invention has been made based on the above-mentioned aspects,
The aim is to create a recording device that can reduce the deterioration of image quality due to recording steps and improve recording speed, while keeping the power consumption and power capacity as low as conventional ones, especially inkjet recording. The goal is to provide equipment.

[Problems to be Solved by the Invention] However, although the above-described divided drive method is advantageous in terms of power consumption and power supply capacity, it has the following problems.

In other words, when dividing driving is performed, a recording step difference equal to the number of divisions may occur in the recorded image due to a difference in the driving timing, and this reduces the quality of the recorded image. To this end, the present invention provides a recording head having a heating element that generates thermal energy used for recording on a recording medium, and selectively driving each of the heating elements according to recording data. and a divided drive signal that sequentially supplies a drive signal for each block to drive a drive element corresponding to each block constituted by a drive element for generating thermal energy and a predetermined number of heating elements. a supply means, a counter for counting the number of recorded data corresponding to a heating element that generates thermal energy, among the recorded data; Simultaneous drive control means for supplying drive signals with overlapping portions in some corresponding drive elements, and divided drive blocks for causing corresponding drive elements to drive using overlapping portions of drive signals supplied by the simultaneous drive control means. The present invention is characterized by comprising a selection means.

Preferably, a plurality of ejection ports for forming ejected droplets, and an electrothermal conversion element provided corresponding to each of the ejection ports for generating thermal energy used to form the ejected droplets. each block constituted by a recording head having a recording head, a drive element for selectively driving each of the electrothermal transducers to generate thermal energy according to print data, and a predetermined number of electrothermal transducers; divided drive signal supply means for sequentially supplying drive signals for each block to drive elements corresponding to the drive elements;
a counter for counting the number of recorded data corresponding to the electrothermal transducer that generates thermal energy; and supply of the drive signal by the divided drive signal supply means according to the count of the counter;
Simultaneous drive control means for supplying drive signals with overlapping portions in drive elements corresponding to some of the blocks, and divided drive for causing corresponding drive elements to drive using overlapping portions in the supply of drive signals by the simultaneous drive control means. The present invention is characterized by comprising block selection means.

[Function] According to the above configuration, it is possible to change the number of blocks to be divided and driven according to recording data.

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

FIG. 1 is a circuit block diagram of a recording head drive circuit showing an embodiment of the present invention. In this example, n electrothermal transducers constitute one block, and m blocks of electrothermal transducers are driven. In this figure, n electrothermal transducers correspond to one unit of the drive IC, which is composed of a flip-flop, a latch circuit, a shift register, and an AND gate.

In the figure, R1 to Rsmn are electrothermal converters, and a common electrode VH for applying a voltage to these converters is connected to one end of each of these electrothermal converters 81 to R1°, Further, the other end of each of the electrothermal transducers n, to R1, is a ground terminal P. is connected to.

EC:LK is a terminal for manually inputting the divided drive signal transfer and lock signal ECL, and the clock signal ECL is connected to flip-flops 51 to 5. Each of them is manually operated as a clock.

Further, a split drive signal El, which will be described later, is input to the zero manual power of the flip-flop 51, and the flip-flops 52 to 5
．． The AND output of each of the Q outputs (EO3 to EOm-+) of the flip-flops at the previous stage and a signal BEG, which will be described later, is input to each D input. The Q outputs of these flip-flops can sequentially activate the drive ICs of the individual blocks.

CLR is a terminal for manually inputting a signal CLR for resetting each of the flip-flops 51-51. 91-9
．． are n-bit shift registers, and their outputs correspond to the n electrothermal transducers of each block, respectively. Reference numeral 51 is a terminal for manually inputting the recording data Sl, and the recording data S which is manually input in serial is input to the first stage shift register a1 based on the recording data transfer lock SCL, and is sequentially shifted into nxm pieces. Recorded data SI of registers 91 to 9. is stored in After transferring one line of recording data as described above, these data are latched by the n-bit latch circuit 8 based on the signal LAT. As described above, each electrothermal conversion element R
, -R,n and the recorded data are associated.

In this example, shift registers 91-9. For the recording data transfer lock SCL, not only clocks are input manually for the number of electrothermal conversion elements for one line, but also clocks are input to the AND gate 4 to perform a logical product with the recording data 51 for one line. , the output of the AND gate 4 is input to the counter circuit 2. Based on this, the counter circuit 2 counts the number of pieces of recording data that are turned on among the electrothermal transducers of one line.

Further, the simultaneous drive control unit 3 has a table of the output of the counter circuit 2 and the pulse width of the signal El corresponding thereto, and refers to this table to perform divided drive according to the number of pieces of record data turned on. Outputs signal El.

The pulse width of the signal El can be set from one cycle of the clock ECLK to the number of cycles of the drive ICs mounted on the recording head (m cycles in this example). If the number of data is less than n bits corresponding to one block of electrothermal conversion element,
The simultaneous drive control unit 3 sets the pulse width of the divided drive signal El to a maximum of m cycles, that is, simultaneously drives all the electrothermal transducer elements corresponding to one line, so that no recording step occurs in the recorded image. be able to. Furthermore, if the number of "ON" data in the data Sr is n bits or more, the pulse width of the divided drive signal El is set according to the number.

BEI is basically a terminal for manually powering the BEI of No. Based on the basic signal BEI, the divided drive block 2 selection circuit 1 selects the signal BEO according to the pulse width and output timing of the divided drive signal El set by the simultaneous drive control section 3.
Output.

The divided drive signal El output from the simultaneous drive control section 3 is sent to the first stage flip-flop 5. 0, and is outputted as Q output EO, in synchronization with clock ECLK.

The signal EO, is inputted to the next stage flip-flop 52, and thereafter is sequentially shifted in the same way to the final stage flip-flop 5. outputs EO,.

Furthermore, the signal BEO output from the divided drive block selection circuit 1 is applied to AND gates 61-6. Human power is applied to each of them. As a result, only when the output (EO0 to EO,) from the flip-flop of each block is "H", BE
G is AND gate 61-6. are output from each of latch circuits 81-8. The electrothermal transducer R, ~ is determined by the logical product (outputs of AND gates 71 to 7) with the recorded data from
Each of R□ is turned on.

FIG. 2 is a timing chart showing the driving timing of the circuit shown in FIG. 1, and the divided driving of this example will be explained in more detail with reference to FIG.

For example, as described above, the electrothermal conversion elements R1 to R,. is selectively driven according to print data, and when the number of blocks determined by the number of "on" blocks of the print data corresponding to one line formed by ejecting ink by this driving is m, that is, conventional Similarly, when driving one block at a time, the pulse El output by the simultaneous drive control section 3
As shown in FIG. 2, the pulse width is equal to one cycle of the clock No. 3 ECL, and this signal El is inputted to the flip-flop 51 and output as a signal EO.

This output signal EO is manually input to the next stage flip-flop 52 and similarly outputted as a signal EO2. The pulse El outputted from the simultaneous drive control section 3 in this manner is applied to the flip-flop 5. ~5. The sequentially shifted output signals EO, .about.EO, are obtained.

Also, at this time, the divided drive block selection circuit 1 outputs its output signal BEG at a timing that overlaps with each of the signals EO, .about.EO.

As a result, AND gates 6, to 6. The output from is sequentially 1
It becomes "H" corresponding to each block, thereby driving each block.

When the pulse width of the pulse El outputted by the simultaneous drive control section 3 according to the output of the counter circuit 2 is equal to two cycles of the clock ECLK, that is, when the drive is performed every two blocks (the number of divided drive blocks is -72), FIG. Each flip-flop as shown in 5. ~5. Each of the output signals EO, .about.EO, has a portion that overlaps with the output adjacent to each other, and at this time, the divided drive block selection circuit 1 sets the output timing of the signal BEG to be output in the above-described portion. That is, first, the first BEG is generated at the part where the outputs EO and EO2 overlap.
Output , and then print the next B at the part where EO3 and EO4 overlap.
EG is output, and the same process is performed thereafter. This causes the two blocks to be driven simultaneously.

As explained above, the number of divided drive blocks can be arbitrarily set in accordance with the number of "on" data of one line of recording data Sl, and this allows the image quality to be improved by the recording step difference in the recorded image. This makes it possible to reduce the decrease in

Note that the relationship between the number of data to be turned on in the recording data St and the pulse width of the signal El can be changed by changing the contents of the above-mentioned table constituted by, for example, a RAM or the like.

FIG. 3 is a circuit block diagram of a recording head drive circuit showing another embodiment of the present invention, and is similar to FIG. 1.

The difference in the configuration from that shown in FIG. 1 is that the flip-flop 5. The signal El inputted to the terminal El has a constant pulse width (No. 8), and the signal ECL inputted manually as a clock to each flip-flop 51 to 5.
is outputted from the simultaneous drive control section 3, and its period is variable according to the output of the counter circuit 2.

That is, the simultaneous drive control section 3 of this example has the counter circuit 2
The frequency of the divided drive signal transfer lock ECL is set according to the number of data that becomes "on" in the recorded data in response to the output of the clock. (basic clock) to m (corresponding to the number of drive ICs in this example) pulses can be set.

On the other hand, the divided drive block selection circuit 1 of this example outputs a signal BEG similar to that of the above-described example, with its output timing appropriately determined according to the frequency information of the signal transfer lock ECLK.

FIG. 4 is a timing chart showing drive timing in the circuit shown in FIG. 3. As shown in the figure, 1
In the case of block drive, the frequency of the signal transfer clock ECLK is set to one pulse within one period, and each flip-flop 5. The signals No. 8 are outputted from each of the signals BEO and BEO are overlapped (they do not become "H" at the same time), and the output timing of the signal BEO is determined accordingly.
Driving is performed sequentially for each l block.

In the case of 2-block drive, the clock ECLK has a cycle in which there are two pulses within one cycle of the basic clock, so the outputs EOI and EO7 overlap, and the outputs EO3 and E
Two sets of outputs such as O4 become "H" at the same time, and BEO is output in synchronization with this.

This makes it possible to drive every two blocks, which reduces deterioration in image quality due to recording step differences in recorded images, and
Recording speed can be improved.

As explained above, according to this example, the transfer lock ECL
By changing the frequency of the block according to the number of "on" data in one line of recording data, it becomes possible to drive the blocks simultaneously by changing the number of blocks.

Note that in the above two embodiments, the number of drive ICs (blocks) is m, and the number of electrothermal converters corresponding to one drive IC is n, but the application of the present invention is limited to these numbers. Of course, the simultaneous drive control section is not a circuit equipped with a selective resistor that can set m stages of pulse width, or a circuit that can selectively generate m types of clocks. You can also.

FIG. 5 is a perspective view showing an example of an inkjet recording device to which the present invention is applied, and the device shown in the figure has four colors of ink, cyan (C), magenta (M), and yellow, so that it is not compatible with full-color recording. There are four recording heads 202C, 202M, 202Y202B corresponding to (Y) and black (K), and each of these heads has ejection ports arranged across the width of the recording paper being conveyed. That is, the electrothermal conversion elements R3 to R shown in FIGS. 1 to 3. correspond to these discharge port arrays.

Although the above embodiments have been described with respect to an inkjet recording device, the application of the present invention is not limited thereto, and even if it is applied to a so-called thermal recording head using an ink ribbon or thermal paper, the predetermined effect can be achieved. It is possible to obtain

[Effects of the Invention] As is clear from the above description, according to the present invention, it is possible to change the number of blocks to be divided and driven depending on recording data.

As a result, it is possible to reduce the deterioration in the quality of recorded images due to the recording level difference due to divided driving, while maintaining the power consumption as low as in the conventional method, and it is also possible to improve the recording speed.

[Brief explanation of drawings]

FIG. 1 is a circuit block diagram of an inkjet recording head drive circuit showing one embodiment of the present invention, FIG. 2 is a timing chart of each signal in the circuit shown in FIG. 1, and FIG. 3 is another embodiment of the present invention. FIG. 4 is a timing chart of each signal in the circuit shown in FIG. 3; FIG. 5 is a circuit block diagram of an inkjet recording head drive circuit showing an example; FIG. 4 is a perspective view, FIG. 6 is a circuit block diagram showing a conventional example of an inkjet recording head drive circuit, and FIG. 7 is a timing chart of each No. 13 in the circuit shown in FIG. 6. 1... Divided drive block selection circuit, 2... Counter circuit, 3... Simultaneous drive control section, 4... AND gate, 51-5. ...Flip-flop, 6, ~61...AND gate, 81~R1゜...Electrothermal conversion element, El...Divided drive signal, ECL...Divided drive signal transfer lock signal . Figure 5

Claims (1)

[Claims] 1) A recording head having a heating element that generates thermal energy used for recording on a recording medium, and selectively driving each of the heating elements according to recording data. , a drive element for generating the thermal energy, and a drive signal for causing the drive to be sequentially supplied to each of the drive elements corresponding to each of the blocks constituted by a predetermined number of the heating elements for each block. a counter for counting the number of recorded data corresponding to the heat generating element that generates the thermal energy among the recorded data; simultaneous drive control means for supplying the drive signals with overlapping parts in the drive elements corresponding to some of the blocks; and the overlapping parts in the supply of the drive signals by the simultaneous drive control means. A recording apparatus characterized by comprising: divided drive block selection means for causing the corresponding drive element to perform the drive. 2) A plurality of ejection ports for forming ejected droplets, and an electrothermal conversion element provided corresponding to each of the ejection ports for generating thermal energy used to form the ejected droplets. a recording head having: a drive element for selectively driving each of the electrothermal transducers to generate the thermal energy according to print data; and a predetermined number of the electrothermal transducers. divided drive signal supply means for sequentially supplying a drive signal for causing the drive element corresponding to each of the blocks to perform the drive; a counter that counts the number of recording data corresponding to a conversion element; and according to the count of the counter, the supply of the drive signal by the divided drive signal supply means is duplicated in the drive elements corresponding to some of the blocks. simultaneous drive control means for supplying the drive signals by the simultaneous drive control means; and divided drive block selection means for causing the corresponding drive elements to perform the drive in the overlapping portions in the supply of the drive signals by the simultaneous drive control means. An inkjet recording device characterized by: 3) The recording apparatus or inkjet recording apparatus according to claim 1 or 2, wherein the simultaneous drive control means causes the overlapping portion to be supplied by changing the pulse width of the drive signal. . 4) The recording apparatus or inkjet recording according to claim 1 or 2, wherein the simultaneous drive control means causes the overlapping portion to be supplied by changing the frequency at which the drive signal is transferred. Device.