JP2020138465A - Element substrate, recording head and recording device - Google Patents

Abstract

To provide an element substrate that is reduced in substrate area to lower manufacturing costs, and also can prevent wrong detection when a plurality of temperature detecting elements are selected, a recording head using the element substrate, and a recording device using the recording head.SOLUTION: An element substrate comprises a plurality of electrothermal conversion elements, a plurality of temperature detecting elements corresponding to the plurality of electrothermal conversion elements, and a common selection circuit which selectively drives the plurality of electrothermal conversion elements and the plurality of temperature detecting elements. The element substrate further comprises a determination circuit which determines whether the number of the selected electrothermal conversion elements is two or larger, and a control circuit which performs control to output an output signal from the selected temperature detecting element to the outside according to a result of the determination by the determination circuit.SELECTED DRAWING: Figure 7

Description

The present invention relates to an element substrate, a recording head, and a recording device, and more particularly to a recording device applied to record a recording head incorporating an element substrate including a plurality of recording elements according to an inkjet method.

In an inkjet recording head (hereinafter referred to as a recording head), ejection failure occurs in all or part of the nozzles due to clogging of the nozzles due to foreign matter, air bubbles mixed in the ink supply path, changes in the wettability of the nozzle surface, and the like. Sometimes. Therefore, in such a recording head, it is an important issue to identify the nozzle in which the ejection failure has occurred and reflect it in the image complementation and the recovery operation of the recording head.

In view of this problem, Patent Document 1 provides a temperature detecting element formed of a thin film resistor through an insulating film on each of the electrothermal conversion elements on the element substrate built in the recording head, and detects the temperature information for each nozzle. Then, we propose a method to inspect nozzles with defective discharge from the temperature change. Further, Patent Document 2 proposes a method of inspecting a nozzle with defective ejection from a temperature change detected by a temperature detecting element provided corresponding to each electric heat conversion element without providing a complicated circuit. ..

Japanese Unexamined Patent Publication No. 2008-023987 Japanese Unexamined Patent Publication No. 2006-337590

However, in Patent Document 1, in order to inspect the discharge failure of each electric heat conversion element, when selecting the temperature detection element corresponding to the electric heat conversion element, the electric heat conversion element and the temperature detection element are selected respectively. Multiple selection circuits are required. Therefore, there is a problem that the area of the element substrate becomes large and the manufacturing cost becomes high. In addition, when detecting the temperature, each electric heat conversion element and the corresponding temperature detection element are selected, but when a plurality of electric heat conversion elements and a plurality of temperature detection elements are selected due to a circuit defect or the like. The temperature information cannot be obtained accurately, and the discharge defect cannot be inspected correctly.

Further, according to Patent Document 2, the circuit for selecting the electrothermal conversion element and the temperature detection element is standardized and the area of the element substrate can be reduced, but a plurality of temperature detection elements are selected as in Patent Document 1. At that time, the temperature information cannot be acquired accurately and the discharge defect cannot be inspected correctly.

The present invention has been made in view of the above conventional example, and is an element substrate which reduces the substrate area to reduce the manufacturing cost and prevents erroneous detection when a plurality of temperature detection elements are selected, and the element substrate thereof. It is an object of the present invention to provide a recording head using the above, and a recording device using the recording head.

In order to achieve the above object, the element substrate of the present invention has the following configuration.

That is, the element substrate selectively drives a plurality of electric heat conversion elements, a plurality of temperature detection elements corresponding to the plurality of electric heat conversion elements, the plurality of electric heat conversion elements, and the plurality of temperature detection elements. A common selection circuit to be used, a determination circuit for determining whether or not the number of electrothermal conversion elements selected by the selection circuit is two or more, and a determination circuit selected by the selection circuit according to the result of determination by the determination circuit. It is characterized by having a control circuit for controlling the output signal from the temperature detection element to be output to the outside.

Looking at the present invention from another aspect, the device substrate having the above configuration, a plurality of discharge ports provided corresponding to the plurality of electric heat conversion elements, and the plurality of electric heat conversion elements are driven. The recording head is provided with an ink supply port for supplying ink discharged from a plurality of discharge ports.

Further, when the present invention is viewed from another aspect, it includes a recording device that discharges ink from a recording head having the above configuration to a recording medium for recording.

According to the present invention, it is possible to reduce the substrate area and prevent erroneous detection when a plurality of temperature detection elements are selected. There is an effect that it is possible to provide an element substrate having both cost reduction and functional improvement.

It is a perspective view for demonstrating the structure of the recording apparatus provided with the full-line recording head which is a typical example of this invention. It is a perspective view which shows the schematic structure of the recording head. It is a figure which shows the detailed structure of the element substrate of the shape of a parallelogram. It is the figure which showed the peripheral part of one electric heat conversion element provided in the element substrate of a multilayer structure in an enlarged manner schematically. It is a block diagram which shows the structure of the element substrate concerning the temperature detection of an electric heat conversion element. It is a figure which shows the example of the layout composition when the drive selection circuit of an electric heat conversion element and a temperature detection element mounted on an element board are made common. It is a circuit diagram which shows the detailed structure of the only one circuit according to Example 1. FIG. It is a circuit diagram which shows the internal structure of the discharge presence / absence determination unit 511A. It is a circuit diagram which shows the internal structure of each row unit determination part 507D. It is a circuit diagram which shows the internal structure of the discharge detection control unit 512n. It is a circuit diagram which shows the detailed structure of the only one circuit according to Example 2. FIG.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiment, not all of the plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the attached drawings, the same or similar configurations are designated by the same reference numbers, and duplicate explanations are omitted.

In this specification, "record" (sometimes referred to as "print") is not limited to the case of forming significant information such as characters and figures, and may be significant or involuntary. It also refers to the case where an image, pattern, pattern, etc. is widely formed on a recording medium or the medium is processed, regardless of whether or not it is manifested so that it can be visually perceived by humans. ..

The term "recording medium" refers not only to paper used in general recording devices, but also to a wide range of media such as cloth, plastic film, metal plate, glass, ceramics, wood, and leather that can accept ink. Shall be.

Furthermore, "ink" (sometimes referred to as "liquid") should be broadly interpreted, as with the definition of "print" above. Therefore, by being applied onto the recording medium, the image, pattern, pattern, etc. are formed, the recording medium is processed, or the ink is processed (for example, the colorant in the ink applied to the recording medium is solidified or insolubilized). It shall represent a liquid that can be produced.

Furthermore, the term "nozzle (sometimes referred to as" recording element ")" collectively refers to the ejection port, the liquid passage communicating with the ejection port, and the element that generates energy used for ink ejection, unless otherwise specified. Shall be.

The element substrate (head substrate) for a recording head used below does not indicate a mere substrate made of a silicon semiconductor, but indicates a configuration in which each element, wiring, or the like is provided.

Further, the term “on the substrate” means not only the top of the element substrate but also the surface of the element substrate and the inside side of the element substrate in the vicinity of the surface. Further, the term "built-in" as used in the present invention does not mean that each element of a separate body is simply arranged as a separate body on the surface of a substrate, but that each element is manufactured as a semiconductor circuit. It indicates that it is integrally formed and manufactured on an element plate by a process or the like.

<Recording device equipped with a full-line recording head (Fig. 1)>
FIG. 1 is a diagram showing a schematic configuration of a recording device 1000 using a full-line recording head that ejects ink and records, which is a typical embodiment of the present invention.

As shown in FIG. 1, the recording device 1000 includes a transport unit 1 for transporting the recording medium 2 and a full-line recording head 3 arranged substantially orthogonal to the transport direction of the recording medium 2, and a plurality of recordings are performed. This is a line-type recording device that continuously records while continuously or intermittently transporting the medium 2. The full-line recording head 3 has a negative pressure control unit 230 that controls the pressure (negative pressure) in the ink path, a liquid supply unit 220 that communicates with the negative pressure control unit 230, and ink supply to the liquid supply unit 220. And a liquid connection portion 111A serving as a discharge port is provided.

The housing 80 is provided with a negative pressure control unit 230, a liquid supply unit 220, and a liquid connection portion 111A.

The recording medium 2 is not limited to the cut sheet, and may be a continuous roll sheet.

The full-line recording head (hereinafter, recording head) 3 can perform full-color recording with cyan (C), magenta (M), yellow (Y), and black (K) inks. A liquid supply unit 220, which is a supply path for supplying ink to the recording head 3, and a main tank are connected to the recording head 3. Further, an electric control unit (not shown) for transmitting electric power and discharge control signals to the recording head 3 is electrically connected to the recording head 3.

Further, the recording medium 2 is conveyed by rotating two transfer rollers 81, 82 provided so as to be separated by a distance of length F in the transfer direction.

The recording head of this embodiment employs an inkjet method that uses heat energy to eject ink. Therefore, each discharge port of the recording head 3 is provided with an electric heat conversion element (heater). The electric heat conversion element is provided corresponding to each discharge port, and ink is discharged from the corresponding discharge port by applying a pulse voltage to the corresponding electric heat conversion element according to a recording signal. The recording device is not limited to a recording device using a full-line recording head having a recording width corresponding to the width of the recording medium described above. For example, it can be applied to a so-called serial type recording device in which a recording head having ejection ports arranged in a transport direction of a recording medium is mounted on a carriage, and ink is ejected to the recording medium while scanning the carriage reciprocatingly for recording.

FIG. 2 is a perspective view showing a schematic configuration of a recording head.

As shown in FIG. 2, in the recording head 3, a plurality of element substrates 100 having a parallelogram shape are arranged side by side in a predetermined direction, and a form generally called a line head is adopted. There is. In FIG. 2, nine element substrates 100 are arranged side by side, but the present invention is not limited to this. Further, the shape of the element substrate is not limited to this, and may be a rectangular shape or a trapezoidal shape.

FIG. 3 is a diagram showing a detailed configuration of an element substrate having a parallelogram shape. In FIG. 3, (a) is a plan view of the element substrate 100, and (b) is an enlarged view of the region A surrounded by the alternate long and short dash line shown in FIG. 3 (a).

As shown in FIG. 3A, a plurality of electrothermal conversion elements 101 are arranged in the X direction on the element substrate 100 to form an element array, and the element array is further plurality (4 in FIG. 3A). One), they are arranged side by side in the Y direction.

Further, a drive selection circuit 203 for driving the electric heat conversion element 101 is provided in parallel along each element row. The drive selection circuit 203 is connected to the electrode pad 201, and supplies the drive current of the electric heat conversion element 101 and the temperature detection element (described later) according to the recording signal supplied from the outside of the recording head 3 via the electrode pad 201. .. In FIG. 3A, the electric heat conversion elements 101 are arranged in a row in the X direction. For example, a plurality of electric heat conversion elements 101 are arranged in the X direction while being arranged in a staggered pattern. Is also good.

As shown in FIG. 3B, an ejection port 5 for ejecting ink is provided corresponding to the electric heat conversion element 101. Further, ink supply ports 300a and 300b are provided on both sides (upper side and lower side in the drawing) of the plurality of ejection ports 5 (electric heat conversion element 101).

FIG. 4 is an enlarged diagram schematically showing a peripheral portion of one electrothermal conversion element provided on an element substrate having a multilayer structure. 4A is an enlarged plan view of a peripheral portion of one electrothermal conversion element 101 viewed from a direction orthogonal to the X direction and the Y direction in FIG. 3A, and FIG. 4B is a view. 4 is a cross-sectional view taken along the line AA of the plan view shown in 4 (a). Further, (c) is a cross-sectional view showing a more detailed configuration of the cross-sectional structure of the element substrate.

In FIG. 4B, a heat storage layer composed of a thermal oxide film 12 (SiO ₂ ) and a BPSG film 13 (a silicon oxide film doped with boron and phosphorus) is formed on the Si (silicon) substrate 11. The electric heat conversion element 101 and the drive selection circuit are passed through the heat storage layer, the temperature detection element 10, the wiring 14 made of aluminum or the like which is the wiring of the temperature detection element 10, and the interlayer insulating film 15 on the Si substrate 11. An aluminum wiring 16 or the like for connecting to the 203 is formed. The electrothermal conversion element 101 is formed of a Ta compound such as TaSiN. The film thickness of the electrothermal conversion element 101 is about 0.01 to 0.05 μm. The temperature detection element 10 is formed of a thin film resistor whose resistance value changes according to the temperature, which will be described later.

Further, a cavitation film 17 and a cavitation resistant film 18 made of SiN or the like are laminated and formed on the aluminum wiring 16 and the electric heat conversion element 101. The passivation film 17 is a film for protecting the semiconductor circuit layer from ink, and is formed on the entire surface by, for example, P-SiN. The cavitation-resistant film 18 is a film for increasing the resistance to cavitation formed on the electric heat conversion element 101, and is formed around the electric heat conversion element 101 by Ta, for example.

The temperature detection element 10 is independently arranged for each electric heat conversion element 101 directly under each electric heat conversion element 101. However, it may be formed not necessarily directly under the electrothermal conversion element 101 but in the vicinity. The wiring 14 connected to each of the temperature detection elements 10 is configured as a part of a detection circuit for detecting temperature information. A discharge port 5 is provided directly above the electric heat conversion element 101.

As shown in FIG. 4A, the temperature detecting element 10 has a meandering shape having a high resistance value in a region overlapping with the electrothermal conversion element 101 in order to output as a high voltage value even with a slight temperature fluctuation. .. However, as long as the material has a high TCR (temperature resistance coefficient), the shape of the temperature detection element 10 may be, for example, a quadrangle that is one size smaller than the electrothermal conversion element 101.

Further, as shown in FIG. 4C, an electric wiring 103 for supplying a current to the electric heat conversion element 101 extends inside the interlayer insulating film 15 provided on the Si substrate 11. The electrical wiring 103 is provided so as to be embedded in the interlayer insulating film 15 in multiple layers. Therefore, in FIG. 4C, in order to distinguish wiring embedded in different layers, they are shown as 103a, 103b, 103c, 103d, and when these are collectively referred to, they are referred to as 103.

The electric wiring 103 electrically connects the drive selection circuit 203, the electric heat conversion element 101, and the temperature detection element (not shown in FIG. 4C) via the connection member 102. The electrical wiring 103 is also made of aluminum and has a film thickness of about 0.6 to 1.2 μm. The electric heat conversion element 101 generates heat due to the supplied current, and the high temperature electric heat conversion element 101 heats the ink in the ink supply port 8 to generate bubbles. Ink in the vicinity of the ejection port 5 is ejected from the ejection port 5 by the bubbles, and recording is performed.

Next, an example of a method of driving the temperature detection element 10 of each electric heat conversion element (heater) in the recording head 3 including the element substrate 100 having the above configuration will be described.

FIG. 5 is a block diagram showing a configuration of an element substrate related to temperature detection of an electrothermal conversion element. In particular, FIG. 5 shows the relationship between the drive selection circuit 203, the electric heat conversion element 101, and the temperature detection element 10. Here, a configuration in which the electric heat conversion element 101 for four segments (denoted as Seg in the figure) constituting one group and the temperature detection element 10 arranged corresponding thereto are arranged will be described as an example. ..

The temperature detection element 10 includes, for example, a temperature detection circuit using a resistance temperature detector, a temperature detection circuit using a thermistor, a temperature detection circuit using a thermocouple, an optical detection circuit using Cds (photoelectric effect), and the like. Is applied. Further, the temperature detection element is not limited to the above example, and is a two-terminal element, and even if the constant current generated by the constant current source is conducted (energized) at the time of non-selection, a DC voltage is passed (that is, that is). Any configuration (which does not cause a voltage drop) may be used.

Four temperature detection elements 10 (first to fourth temperature detection elements) are provided in one group 100G of the element substrate 100. The four temperature detection elements 10 are provided corresponding to the vicinity of each of the four electric heat conversion elements 101 (first to fourth electric heat conversion elements). As shown in FIG. 5, one terminal of each electric heat conversion element (Seg1 to Seg4) 101 is commonly connected (in parallel) to the wiring 601 that supplies the drive voltage VD to the electric heat conversion element 101, and the other terminal. The terminal is connected to the drive switch 116. The other terminal of the drive switch 116 is connected to the GND wiring 602, which is the return (recovery) destination of the drive voltage VD.
The drive switch 116 is connected to the drive selection circuit 203, and is on / off controlled according to a selection signal (a signal instructing selection of the corresponding temperature detection element 10) from the drive selection circuit 203.

Further, as shown in FIG. 5, in the temperature detection element 10 corresponding to the electric heat conversion elements (Seg1 to Seg4) 101, one terminal (first terminal) of the constant current IS supplied from the constant current source. It is commonly connected to the wiring (constant current common wiring) 603. The other terminal (second terminal: a terminal provided on the opposite side of the first terminal via the temperature detecting element) is connected to the selection switch 103 and the read switch 104. The selection switch 103 serves as a selection unit that selects the temperature detection element 10 and causes the temperature detection element 10 to selectively conduct the constant current IS from the constant current source to perform the detection operation.

The read switch 104 reads the terminal voltage and outputs the read voltage as the discharge detection output signal 600. Therefore, the discharge detection output signal 600 is output from one terminal of the read switch 104, and the other terminal of the selection switch 103 is connected to the VSS wiring 604 which is the return destination of the constant current IS. That is, the constant current IS is conducted to the temperature detection element 10 by turning on / off the selection switch 103.
Then, the selection switch 103 and the read switch 104 of the temperature detection element 10 corresponding to the four electric heat conversion elements (Seg1 to 4) are commonly connected to the electric heat conversion element 101 and the corresponding temperature detection element 10. On / off control is performed according to signals D1 to D4. Since the conventional element substrate adopts a configuration in which a circuit for selecting an electrothermal conversion element and a temperature detection element is separately provided, the substrate area is increased accordingly. On the other hand, in the element substrate according to this embodiment, the circuit area is significantly reduced while maintaining the selection function by sharing the drive selection circuit for selecting the electrothermal conversion element and the temperature detection element.

The drive selection circuit 203 is configured to include a 1-bit shift register and a 1-line decoder, and is driven in 4 time division manners. Therefore, in the four-segment electric heat conversion element, the electric heat conversion element (and the corresponding temperature detection element) that is simultaneously driven is limited to one segment. Hereinafter, this 4-segment unit is referred to as a "group". The four electrothermal conversion elements forming the group are arranged close to each other.

The drive selection circuit 203 generates selection signals D1 to D4 by receiving row data for turning on / off the electric heat conversion element and the corresponding temperature detection element and column data for designating a time division block. At this time, the drive selection circuit 203 outputs information as to whether or not there is a segment (Seg) to be turned on in one group in charge of itself as a drive presence / absence signal (first signal) 530, and is a one-of-a-kind circuit described later. Is used as information for operating.

In this embodiment, one group is divided into four segments for the sake of simplicity, but the present invention is not limited to this. Further, when actually performing discharge detection, it has a discharge detection mode. The ejection detection mode is a mode in which it is confirmed by using a temperature detection element corresponding to each nozzle whether ink is ejected normally from the nozzles. When this mode is set, the voltage of an arbitrarily selected temperature detection element is output.

Here, the operation of the element substrate 100 will be described by taking as an example a case where the temperature detecting element 10 corresponding to the electrothermal conversion element (Seg1) is selected.

First, the selection switch 103 and the read switch 104 are turned on according to the selection signal D1 from the drive selection circuit 203, and the constant current IS is supplied to the temperature detection element 10 corresponding to the electrothermal conversion element (Seg1). At this time, the constant current IS is not supplied to the temperature detection element 10 corresponding to the other electric heat conversion elements (Seg2 to Seg4). As a result, the temperature detection element 10 corresponding to the electric heat conversion element (Seg1) is in the selected state, and the terminal voltage corresponding to the detection amount is generated. The terminal voltage on the b side of the selection switch 103 of the temperature detection element 10 is output as a discharge detection output signal 600 via the read switch 104.

The drive selection circuit 203 is also provided with terminals for inputting the recorded data signal D_D, the clock signal CLK_D, the latch signal LT, and the enable signal EN, respectively. Since these signals are known, the description thereof will be omitted.

FIG. 6 is a diagram showing an example of a layout configuration when the drive selection circuit of the electrothermal conversion element and the temperature detection element mounted on the element substrate are shared.

As shown in FIG. 6, the electric heat conversion element 101 and the corresponding temperature detection element 10 are arranged between the two ink supply ports 300a and 300b. Further, the selection switch 103 of the temperature detection element 10 is arranged below the ink supply port 300b, and the drive switch 116 of the electric heat conversion element 101 is arranged below the ink supply port 300a. Since the drive switch 116 is a place where the voltage fluctuates greatly, in order to avoid the influence of high frequency noise caused by the fluctuation, it should be arranged at a position away from the wiring 14b for driving the selection switch 103. Is desirable. Further, a drive selection circuit 203 is arranged above the ink supply port 300b, and is connected to each electric heat conversion element and temperature detection element through wirings 14a and 14b, respectively.

With the layout as described above, even if the drive selection circuit 203 that selectively drives the electric heat conversion element 101 and the temperature detection element 10 is shared, it is possible to efficiently improve the noise resistance.

FIG. 7 is a circuit diagram showing a detailed configuration of the only one circuit.

The only-one circuit is an electrothermal conversion element mounted on the element substrate 100, in which the above-mentioned "groups" are grouped into an arbitrarily determined number of "units", and the grouped units are discharged and driven only within one unit ( It is a circuit to confirm that discharge detection) is not performed. In this embodiment, in order to reduce the area of the element substrate as much as possible, it is assumed that the discharge detection output data 501 by discharge detection is processed by one system of discharge detection processing circuits (not shown). Therefore, if the discharge drive (discharge detection) of two or more segments is executed at the same time when the discharge is detected, the discharge detection output data 501 will be duplicated and accurate data cannot be acquired. Therefore, it is very important to confirm that the discharge can be detected only in one unit (1 Seg) with an arbitrarily determined number of units.

FIG. 7 shows all the electrothermal conversion elements and the temperature detecting elements provided on the element substrate 100. As mentioned above, one group contains four segments. As can be seen from FIG. 7, the element substrate 100 has element rows formed from 64 groups (that is, 256 segments) arranged for 5 rows (rows A to E). Focusing on each column, for example, the units 502A, 504A, 505A, and 506A in the A column are grouped into 16 groups (1 group has 4 segments). Columns B to E are also grouped into the same number of units. In FIG. 7, the units in row B are labeled 502B, 504B, 505B, 506B, the units in row C are labeled 502C, 504C, 505C, 506C, and the units in row D are 502D, 504D, 505D, Notated as 506D. The units in row E are designated as 502E, 504E, 505E, and 506E. That is, 16 groups are grouped into one unit in any column.

These 20 units have the same configuration. As shown in units 502A and 502B, each unit is provided with a logic circuit (OR circuit) for each group. This is to confirm the presence or absence of discharge drive in the unit.

Further, as can be seen from FIG. 7, 20 units are arranged in a matrix structure, and 4 row unit determinations having the same internal configuration can be determined so that the presence or absence of discharge drive can be determined for each of 16 groups in the row direction. Circuits 507A, 507B, 507C, and 507D are provided.

Next, the operation in the unit will be described by taking units 502A and B as an example.

The unit is confirmed by connecting the drive presence / absence signals 530, which are output from the drive selection circuit 203 in one group shown in FIG. 5, indicating the presence / absence of discharge drive in the group, by connecting them in an OR circuit that calculates the logical sum. Internal drive presence / absence signals 540A and 540B are output. The in-unit drive presence / absence signals 540A and 540B are connected to the discharge presence / absence determination circuits 511A and 511B and the discharge detection control circuits 512A and 512B, respectively. Further, these determination circuits, control circuits, etc. are similarly arranged in all the units. The discharge detection control circuit is a circuit that controls to output a signal from the temperature detection element to the outside.

The internal configuration of the discharge presence / absence determination circuits 511A and 511B and the internal configuration of the discharge detection control circuits 512A and 512B are the same.

FIG. 8 is a circuit diagram showing the internal configuration of the discharge presence / absence determination circuit 511A. Since the discharge presence / absence determination circuit 511n is provided in each row of units and has the same configuration, the discharge presence / absence determination circuit 511n in each row is specified with n = A to E.

First, an in-unit drive presence / absence signal (second signal) 540A is input to the discharge presence / absence determination circuit 511A. The signal terminals 532 and 513 are connected to the ground VSS only in the unit 502A. Outputs from the discharge presence / absence determination circuits 511n (n = A to D) of the units in the front row are input to the discharge presence / absence determination circuits 511n (n = B to E) of the units in the other rows.

As can be seen from FIG. 8, the discharge presence / absence determination circuit 511n is composed of two OR circuits 511-1 and 511-2 and one AND circuit 511-3.

When there is discharge drive in the unit and the in-unit drive presence / absence signal 540A is "H", the in-unit drive determination signal 534A outputs "H", and when there is no discharge drive, "L" is output (to the unit 502A). The multiple unit drive determination signal 533A is "L"). The in-unit drive determination signal 534A and the plurality of unit drive determination signal (third signal) 533A are output to the discharge presence / absence determination circuit 511B. In the discharge presence / absence determination circuit 511B, the in-unit drive presence / absence signal 540B in the unit 502B is input (the output is “H or L” as in the discharge presence / absence determination circuit 511A).

Further, the output of the discharge presence / absence determination circuit 511B is determined by the in-unit drive determination signal 534A and the plurality unit drive determination signal 533A. When the unit 502A also has a discharge drive (the in-unit drive determination signal 534A is "H") and the unit 502B also has a discharge drive, an "H" is output by the multiple unit drive determination signal 533B. This indicates that the ejection drive of a plurality of units was performed.

Similarly, these decisions are made for units in all columns. The result of the E column unit is output to each row unit determination circuit 507A to D.

FIG. 9 is a circuit diagram showing the internal configuration of each row unit determination circuit 507D. Since each row unit determination circuit 507n is provided in each row and its configuration is the same, each row unit determination circuit 507n is specified with n = A to D. In FIG. 9, each row unit determination circuit 507D is illustrated as an example. As can be seen from FIG. 9, each row unit determination circuit 507n is composed of two OR circuits 507-1 and 507-2 and one AND circuit 507-3.

As can be seen from the matrix configuration of the units shown in FIG. 7, the row unit determination circuit 507D is the final arrival part of the determination result by each unit. There, the in-unit drive determination signal 534E and the plurality of unit drive determination signals 533E, which are the determination results of the presence / absence of discharge drive in each row unit, are input. Further, the row unit drive determination signal 537C and the plurality row unit drive determination signal 536C, which are the determination results of the presence / absence of discharge drive, are also input from the adjacent row unit determination circuit 507. Further, as an output, a row unit drive determination signal 537D as a signal indicating the presence or absence of discharge drive in the units up to the row unit determination circuit 507D and a plurality of lines as a signal indicating whether or not the discharge drive is performed by a plurality of units. The unit drive determination signal 538D is output. Here, when there is discharge drive in a plurality of units, the multi-line unit drive determination signal 538D becomes “H”.

As described above, in this embodiment, it is determined whether or not a plurality of discharge drives are performed in all the units by using the discharge presence / absence determination circuit and each row unit determination circuit 507 in each unit.

These results are input to the only one signal output circuit 503. Then, from the only one signal output circuit 503, the only one signal (fourth signal) which becomes "L" when there is discharge drive in a plurality of units and "H" when there is no discharge drive in a plurality of units. Feedback is output to all units.

FIG. 10 is a circuit diagram showing the internal configuration of the discharge detection control circuit 512n. Since the discharge detection control circuit 512n is provided in each row and the configuration is the same, the discharge detection control circuit 512n in each row is specified with n = A to E. As can be seen from FIG. 10, the discharge detection control circuit 512n is composed of an AND circuit 512-1, a comparator 512-2, and a switch 512-3.

As shown in FIG. 10, four signals are input to the discharge detection control circuit 512n. The first is the only one signal 539, the second is the in-unit drive presence / absence signal 540n, the third is the discharge detection mode signal 500, and the fourth is the discharge detection output signal 600. When it is confirmed by these signals that there is no discharge drive in multiple units, that the target unit has discharge drive, and that the discharge detection mode is set, the switch 512-3 of the discharge detection control circuit 512n is activated. Then, the discharge detection output data 501 is output.

The discharge detection output data 501 is output to a discharge detection processing circuit (not shown).

With the above configuration, it is possible to prevent discharge detection when multiple discharge drives (two segments or more) are detected for each arbitrarily determined "unit", thereby acquiring accurate discharge detection output data. Is possible.

In the configuration described above, the units are grouped into 4 segments × 16 groups, but the present invention is not limited to this, and the number of units grouped for each unit does not have to be unified. By grouping the number of units into smaller numbers, it is possible to determine the presence or absence of simultaneous discharge drive in more detail.

Therefore, according to the above-described embodiment, it is possible to reduce the element substrate area as compared with the conventional configuration and prevent erroneous detection when a plurality of temperature detecting elements are selected. This makes it possible to provide an element substrate having both cost reduction and functional improvement.

FIG. 11 is a circuit diagram showing a detailed configuration of the only one circuit according to the second embodiment. In FIG. 11, the same components that have already been described with reference to FIG. 7 are assigned the same reference numbers, and the description thereof will be omitted.

In the second embodiment, it is assumed that four discharge detection processing circuits (not shown) for processing the discharge detection output data 501 are provided as compared with the first embodiment, and four discharge detection output data 501A to D are output. It is supposed to be. Further, the row unit determination circuits 507A to D are eliminated, and only one signal output circuits 503A to D are newly arranged at the end points of each row unit according to the number of discharge detection processing circuits.

Therefore, according to the above-described embodiment, the circuit scale is slightly larger, but there is an advantage that multiple discharge drives can be detected when there are a plurality of discharge drives in each row unit.

As shown in FIG. 11, the only one signal output circuits 503A to D are arranged at the end points of the units in the row direction, but the present invention is not limited to this. For example, the only one signal output circuit may be arranged at the end point of the unit in the column direction.

The present invention is not limited to the above embodiment, and various modifications and modifications can be made without departing from the spirit and scope of the invention. Therefore, a claim is attached to make the scope of the invention public.

3 Recording head, 5 Discharge port, 10 Temperature detection element, 100 element substrate,
101 electrothermal conversion element, 203 drive selection circuit, 1000 inkjet recorder

Claims (11)

With multiple electrothermal conversion elements
A plurality of temperature detection elements corresponding to the plurality of electrothermal conversion elements, and
A common selection circuit that selectively drives the plurality of electrothermal conversion elements and the plurality of temperature detection elements,
A determination circuit for determining whether or not the number of electrothermal conversion elements selected by the selection circuit is two or more,
An element substrate comprising a control circuit for controlling to output an output signal from a temperature detection element selected by the selection circuit to the outside according to the result of determination by the determination circuit. The element substrate has a multi-layer structure and has a multi-layer structure.
A layer different from the layer in which the electric heat conversion element is provided, and a temperature detection element corresponding to directly below or in the vicinity of the electric heat conversion element is provided.
The element substrate according to claim 1, wherein the selection circuit simultaneously selects an electric heat conversion element and a temperature detection element corresponding to the electric heat conversion element. The plurality of electrothermal conversion elements are divided into a plurality of groups for each of the plurality of electrothermal conversion elements arranged in the vicinity of each other.
The selection circuit is provided in each of the plurality of groups.
The element substrate according to claim 2, wherein each of the plurality of selection circuits outputs a first signal indicating whether or not the electrothermal conversion element of the group in charge is selectively driven. The element substrate according to claim 3, wherein the first signal output by each of the plurality of selection circuits is calculated by ORing by a plurality of OR circuits. The plurality of electrothermal conversion elements are arranged in a predetermined direction to form an element sequence.
A plurality of the element trains are arranged side by side in a direction different from the predetermined direction.
A plurality of groups constituting the plurality of element trains form a plurality of units by grouping a predetermined number of groups arranged in the vicinity of each other.
The fourth aspect of claim 4, wherein the plurality of units are arranged in a matrix structure when the predetermined direction is a column direction and a direction different from the predetermined direction is a row direction. Element substrate. Each of the plurality of units has a second signal indicating whether or not there is an electrothermal conversion element selectively driven inside each unit based on the first signal output by each of the plurality of selection circuits. And, based on the second signal and the second signal output from the adjacent unit, a third signal indicating whether or not a plurality of electrothermal conversion elements are selectively driven is generated. The element substrate according to claim 5. The determination circuit is characterized in that a fourth signal indicating whether or not the number of selected electrothermal conversion elements is two or more is generated based on the second signal and the third signal. The element substrate according to claim 6. The control circuit is an output signal from the temperature sensing element corresponding to the selected electrothermal conversion element when the fourth signal indicates that the number of the selected electrothermal conversion elements is one. The element substrate according to claim 7, wherein the device is output. The element substrate according to any one of claims 1 to 8.
A plurality of discharge ports provided corresponding to the plurality of electrothermal conversion elements,
A recording head characterized by having an ink supply port for supplying ink discharged from the plurality of ejection ports by driving the plurality of electrothermal conversion elements. The recording head according to claim 9, wherein the recording head is a full-line recording head. A recording device for recording by ejecting ink from the recording head according to claim 9 or 10 onto a recording medium.

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