Recording element board

Abstract

To provide a configuration of a recording element board that is capable of reducing wire resistance, improving the layout, and accommodating an increase in frequency as compared with the conventional configuration.SOLUTION: One embodiment of the present disclosure is a recording element board including a plurality of recording elements configured to eject a liquid, the plurality of recording elements being arrayed in a first direction to form a recording element array; a heat generating element configured to heat the liquid; a driver configured to drive the heat generating element; a data processing circuit configured to control the driver; and a plurality of PADs into which a signal to be sent to the data processing circuit is inputted from outside, the plurality of PADs being arrayed in the first direction to form a PAD array, where the data processing circuit is provided in at least two or more systems between the recording element array and the PAD array in a second direction orthogonal to the first direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a technology of a recording element substrate included in a recording apparatus that performs recording by discharging a liquid.

Background Art

[0002] In a recording element substrate used in a recording apparatus that performs recording by discharging a liquid such as ink, in recent years, with the demand for higher image quality and higher functionality, temperature control for controlling the temperature of the recording element substrate has been performed. Also, in order to meet this demand, there is a tendency to increase the number of nozzles on the recording element substrate and to increase the frequency of nozzle driving.

[0003] In a recording element substrate, the amount and discharge speed of droplets discharged vary depending on the temperature. Therefore, when a temperature distribution occurs in the substrate temperature, that temperature distribution directly becomes unevenness in the image and the image quality deteriorates.

[0004] Patent Document 1 discloses a method for suppressing temperature unevenness in a substrate by mounting a driver for a sub-heater in a specific area within a recording element substrate and arbitrarily selecting and heating one or more of those areas as a method for correcting the temperature distribution of the substrate.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the configuration of Patent Document 1 has a configuration in which there is only one data processing circuit that stores data for selectively driving a sub-heater by external data input. With this configuration, it is not possible to sufficiently meet the above-described demands for higher image quality and higher functionality.

[0007] In the case where the data processing circuit has a single configuration, the wiring connecting from the data processing circuit to the switches driving all the sub-heaters becomes long, and the layout on the substrate becomes complicated. Further, regarding the input of data to such a configuration, basically only one transmission line can be supported. Then, when the number of sub-heaters to be driven is large, the number of input data increases, so that it becomes impossible to cope with high frequencies.

[0008] Therefore, an object of the present disclosure is to provide a configuration of a recording element substrate capable of reducing wiring resistance, improving the layout, and coping with high frequencies as compared with the prior art.

Means for Solving the Problems

[0009] One embodiment of the present disclosure is a plurality of recording elements for discharging a liquid, the plurality of recording elements arranged to form a recording element row, a heating element for heating the liquid, a driver for driving the heating element, a data processing circuit for controlling the driver, and a plurality of PADs for inputting signals sent to the data processing circuit from the outside, the plurality of PADs arranged to form a PAD row, and the data processing circuit is provided with two or more between the recording element row and the PAD row. A recording element substrate characterized by that.

Effects of the Invention

[0010] According to the present disclosure, it is possible to provide a configuration of a recording element substrate capable of reducing wiring resistance, improving the layout, and coping with high frequencies as compared with the prior art.

Brief Description of the Drawings

[0011]

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Mode for Carrying Out the Invention

[0012] [First Embodiment] Hereinafter, with reference to the drawings, the liquid ejection head and the recording element substrate constituting the liquid ejection head in this embodiment will be described. Note that the following embodiments are not intended to limit the invention according to the claims more than necessary. Also, although a plurality of features are described in the following embodiments, all of the plurality of features are not necessarily essential for solving the problems of the present disclosure, and the plurality of features may be arbitrarily combined. Furthermore, in the accompanying drawings, the same or similar configurations may be given the same reference numerals, and redundant explanations may be omitted.

[0013] FIG. 1 is a simplified perspective view showing the appearance of the liquid ejection head in the present embodiment. FIG. 1(a) shows a liquid ejection head 100 in which a plurality of recording element substrates 101 are arranged side by side. This liquid ejection head is generally in a form called a "line head".

[0014] FIG. 1(b) shows, as another form different from FIG. 1(a), a liquid ejection head 100 in which two recording element substrates 101 are arranged side by side. This liquid ejection head is generally in a form called a "serial head". In this example, a case where the liquid ejection head has two recording element substrates is shown, but a serial head type liquid ejection head generally has one or two recording element substrates.

[0015] FIG. 2 is a plan view showing the shape of the recording element substrate 101 in the present embodiment. The recording element substrate 101 in FIG. 2(a) has a parallelogram shape, and as a result of a plurality of PADs 102, which are electrical input / output locations, being provided along one of the two longer sides of the parallelogram, a PAD row is formed parallel to that side. The PAD 102 is an electrode for inputting a signal to be sent to a data processing circuit (see FIG. 3) described later from the outside to the recording element substrate 101.

[0016] The recording element substrate 101 in FIG. 2(b) has a parallelogram shape, and as a result of a plurality of PADs 102 being provided along each of the two longer sides of the parallelogram, two PAD rows are formed.

[0017] The recording element substrate 101 in FIG. 2(c) has a rectangular shape, and as a result of a plurality of PADs 102 being provided along one of the two longer sides of the rectangle, a PAD row is formed parallel to that side.

[0018] The recording element substrate 101 in FIG. 2(d) has a rectangular shape, and as a result of a plurality of PADs 102 being provided along each of the two longer sides of the rectangle, two PAD rows are formed.

[0019] The shape of the recording element substrate is generally the shapes shown in FIGS. 2(a) to 2(d), but is not limited thereto. For example, the shape may be trapezoidal, and the arrangement of PAD102 is also various. The shape of the recording element substrate may be a rectangular shape composed of a long side and a short side.

[0020] FIG. 3 is a diagram showing the layout of the recording element substrate in the present embodiment. At the substrate end of the recording element substrate 101, a plurality of PAD102 are provided side by side in the Y direction. These PAD102 include signal terminals, power supply terminals, etc. for receiving data for selecting nozzles that eject ink.

[0021] The recording element substrate 101 has a plurality of heaters 103. The heater 103 is a recording element for ejecting a liquid such as ink. In this example, the plurality of heaters 103 are arranged in the Y direction, and columns A to D are provided as heater columns (also referred to as recording element columns).

[0022] An ink supply port 106 for supplying ink ejected from the nozzles is provided along the heater column in the recording element substrate 101, and the ink flowing in from the ink supply port 106 is supplied above the heater 103.

[0023] A discharge port 205 (see FIGS. 8(b) and 9(b)) is arranged directly above the heater 103. A current is passed through the heater 103 at an arbitrary timing to heat or foam the ink, and ink droplets are discharged from the discharge port 205. Incidentally, in the present embodiment, a heater is taken as an example of the element for ink ejection, but a configuration in which ink is ejected by pressurizing the ink using a piezo element or the like may also be used.

[0024] The recording element substrate is provided with a plurality of sub-heaters 105. The sub-heater 105 is an element for controlling the temperature of the recording element substrate 101 and the ink, and specifically, it is a heating element for temperature adjustment for heating or keeping warm. The sub-heater driver 108 is connected to the sub-heater 105 and performs ON / OFF control (control to turn ON from OFF or OFF from ON) of the current flowing through the sub-heater 105. Incidentally, the detailed configuration around the sub-heater 105 of the present embodiment will be described later with reference to FIG. 7.

[0025] Regarding the wiring between the data processing circuit 110 and the sub-heater driver 108, it is routed like the data processing circuit - sub-heater driver connection wiring 111. "Sub-heater control signals", which are signals for driving each of the plurality of sub-heaters 105, are stored in the data processing circuit 110. Specifically, the sub-heater control signals in this example are SH_A1 to SH_A5 for column A, SH_B1 to SH_B5 for column B, SH_C1 to SH_C5 for column C, and SH_D1 to SH_D5 for column D. The sub-heater control signals SH_A1 to SH_D5 are each transmitted to the corresponding sub-heater driver at an arbitrary timing. As shown in the figure, the wiring between the data processing circuit 110 and each of the plurality of sub-heater drivers 108 is all individual wiring.

[0026] In the present embodiment, by providing two data processing circuits 110 between the columns of the PAD 102 and the recording element column (specifically, column A), the recording element substrate 101 is made into two wiring systems. With this configuration, the individual wiring layout area for each sub-heater is basically reduced by about half, and the wiring layout is improved. Also, since the wiring length can be shortened, the risk of malfunction due to noise is also reduced. Further, in this example, a case where the recording element substrate 101 has two data processing circuits 110 is shown, but the number of systems of the data processing circuit 110 is not limited to 2, and at least two or more data processing circuits may be provided.

[0027] FIG. 4 is a diagram of a circuit for driving the sub-heater 105 and shows a circuit configuration corresponding to FIG. 3. In FIG. 4, PAD102a is a + power supply PAD and PAD102b is a GND PAD.

[0028] As shown in FIG. 6, the wiring layer of the recording element substrate of the present embodiment has a four-layer structure composed of four layers of aluminum (hereinafter referred to as Al). In this specification, for these four layers, the lowermost layer is defined as the first layer, the intermediate layers are defined as the second layer and the third layer from bottom to top, and the uppermost layer is defined as the fourth layer.

[0029] The GND wirings of the heater 104 and the sub-heater 105 are provided on the fourth layer 203a which is the uppermost layer. The + power supply wirings of the heater 104 and the sub-heater 105 are provided on the third layer 203b which is an intermediate layer closer to the uppermost layer.

[0030] Logic wirings are provided on the second layer 203c which is an intermediate layer closer to the lowermost layer and the first layer 203d which is the lowermost layer. This logic wiring is used for the data processing circuit - sub-heater driver indirect connection wiring 111 and the like described above. The recording element substrate of the present embodiment is configured to supply power to the sub-heater via the + power supply wiring of the third layer 203b from the + power supply PAD and then exit to the PAD102b which is the GND PAD via the GND wiring of the fourth layer 203a. Incidentally, these power supply PADs may be used as the power supply PADs for the heater 104 used for discharging ink droplets.

[0031] The sub-heater driver 108 controlled by the sub-heater control signals SH_A1 to SH_D5 drives the sub-heater. As a result, any of the 20 heating areas 107 within the recording element substrate 101 are heated. Incidentally, when it is desired to control the temperature within the recording element substrate with higher accuracy than in this example (Fig. 3), more than 20 heating areas may be provided. As shown in Fig. 3, when focusing on a certain heater row (any one of rows A to D), a plurality of ink supply ports 106 are arranged along the extension direction of the heater row to form a supply port row, and this supply port row is formed in two rows so as to sandwich the heater row. Also, the sub-heater driver 108 is arranged further outside these two rows of ink supply ports in the left-right direction in the figure when taking the ink supply port 106 as a reference. Incidentally, the sub-heater control signals SH_A1 to SH_D5 may be directly supplied from the PAD 102, or may be generated by being converted from a data signal within the recording element substrate 101.

[0032] When focusing on any one heating area, two supply port rows are provided per recording element row, and the sub-heater driver 108 is arranged in the region on the side of the recording element row and the opposite side when taking the relatively closer supply port row of the two supply port rows as a reference in the X direction.

[0033] Here, Fig. 5 shows a block diagram when the sub-heater control signal is generated within the recording element substrate. In the case of the method of Fig. 5, if the control signal data is sent to the data processing circuit 110 via the PAD 102 simultaneously with the image data, the sub-heater control signal is generated by the data processing circuit 110 based on the control signal data. Thus, according to the method of Fig. 5, sub-heater control becomes possible without the need to particularly increase the PAD 102 for supplying the sub-heater control signal.

[0034] In FIG. 3, a plurality of sub-heaters 105 are arranged side by side in the long side direction of the chip (Y direction in the figure), and in the X direction orthogonal to the Y direction, the sub-heater 105 is arranged between the ink supply port 106 and the heater 103. With this arrangement, since the ink near the heater 103 is heated, the ink to be ejected can be heated more efficiently than when the sub-heater 105 is not provided. The layout of the sub-heaters in the plurality of heating areas 107 in the recording element substrate is substantially the same and basically all the same. The number of heaters 104 included in each of the plurality of heating areas 107 is equal. Therefore, basically, the heat generation amounts by the sub-heaters in each area are all equal, and temperature control can be performed to make the temperature distribution in the recording element substrate 101 uniform. However, considering that a temperature difference is likely to occur at the end of the recording element substrate or the like, when changing the heat generation amount of the sub-heater for each area, the temperature can be adjusted for each area by adjusting the layout of the sub-heaters.

[0035] FIG. 7 is a diagram showing the configuration of the sub-heater 105 in the present embodiment. Specifically, FIG. 7(a) is a top view of the sub-heater, and FIGS. 7(b) to 7(f) are cross-sectional views of the sub-heater. Here, polysilicon (described as Poly-Si) is used as the sub-heater material, but the sub-heater material is not limited to polysilicon.

[0036] In FIG. 7(a), the sub-heater 105 in the heating area 107 is composed of five heat generating portions 209 and four bypass portions 208. As shown in FIG. 7(b), this bypass portion 208 is composed of an Al wiring 203 and a plug 206. The resistance value of the bypass portion 208 is sufficiently smaller than that of the sub-heater 105, being in the range of 1 / 100 to 1 / 1000, and is estimated to be 0 ohm in this example. The bypass portion 208 can be composed of at least one of aluminum (Al), copper (Cu), gold (Au), nickel (Ni), tungsten (W), titanium (Ti), and their compounds.

[0037] The plug 206 can be made of, for example, tungsten (W). By connecting the Al wiring 203 with relatively low resistance to the Poly-Si wiring of the sub-heater 105, the current flowing through the heating area 107 flows alternately through the heat generating part 209 and the bypass part 208 as shown by the arrow 212 in Fig. 7(b). In the sub-heater 105, most of the current flows through the portion located between adjacent Al wirings 203, so this portion functions as the heat generating part 209 and generates heat. In this way, the Al wiring 203 is connected so as to be at both ends with respect to any heat generating part 209 and is connected in parallel with the portion other than the heat generating part in the sub-heater 105. With the configuration described above, in the heating area 107, when the sub-heater 105 is energized, current flows through the Al wiring 203 via the plug 206 in the middle of the path of the current flowing through this sub-heater 105. In the sub-heater 105 of this embodiment, since the heat generating parts 209 that generate heat are dispersedly arranged with respect to the heating area 107, it might seem that the heating area 107 cannot be heated uniformly. However, the adjacent heat generating parts 209 are connected by the bypass part 208 made of metal with low thermal resistance, and thus the heat generated in the heat generating part 209 diffuses through the bypass part 208, so that the heating area 107 is uniformly heated.

[0038] In addition, when it is desired to heat the heating area 107 more uniformly, the length of the bypass part 208 can be shortened, and the area can be expanded while maintaining the ratio of the length to the width of the heat generating part 209. However, in this case, the effect of reducing the area of the circuit and the substrate (shrink effect) is reduced.

[0039] Conversely, if the length and width of the heat generating part 209 are reduced and the length of the bypass part 208 is increased, a high shrinkage effect can be obtained. However, in this case, since the current density flowing through the wiring increases, there is a concern about disconnection due to electromigration or the like. "Electromigration" refers to a phenomenon in which metal atoms move when an electric current flows through metal wiring inside an integrated circuit. In aluminum wiring, aluminum atoms move in the direction of electron flow, voids are generated on the cathode side, resulting in an open failure, and hillocks and whiskers grow on the anode side, ultimately leading to a short circuit failure.

[0040] Figure 7(c) shows an example of disconnection due to electromigration. Since the current concentrates on the plug 206, electromigration is relatively likely to occur at the contact part with the Al wiring 203. Usually, the circuit is designed so that such a defect does not occur within a certain current range, and further measures such as sandwiching a barrier metal between the Al wiring 203 and the plug 206 are taken. In this embodiment, even if a disconnection occurs in the Al wiring 203, since the sub-heater 105 is wired over the heating area 107, the current bypasses to the Poly-Si wiring of the sub-heater 105 as a result, and the sub-heat function is not lost. By such a wiring method, high reliability of sub-heat drive can be obtained. However, since the resistance increases when a disconnection occurs, the heat generation amount decreases. Therefore, in the event of a disconnection, it is desirable to suppress the drive of the sub-heater in the area where the disconnection has occurred as much as possible.

[0041] As shown in the current path of arrow 212, since the resistance of the sub-heater 105 is high, the current tries to flow through the Al wiring 203 with lower resistance. Therefore, as shown in FIG. 7(b), even if two rows of plugs 206 are provided in the end Al wiring 203, the current flows through the front-side plug as seen from the heat generating part 209. However, regarding the power outlets at both ends of the sub-heater, if a disconnection occurs, the sub-heating function will be lost. Therefore, by providing two or more rows of plugs 206, even if a disconnection occurs on the front side, the current can flow through the back-side plug. With such a configuration, it becomes possible to prevent a complete disconnection at both ends of the sub-heater. In addition, since the same effect can be obtained in the Al wiring 203, the Al wiring 203 may be arranged in two or more rows instead of (or together with) the plug 206.

[0042] In FIG. 7(d), the length of the Al wiring is longer than that in FIG. 7(b). By adopting such a design, as shown by the arrow in the figure, it becomes possible to adjust the calorific value only by changing the position of the plug. For example, when the plug 206 is arranged close to the end of the Al wiring 203 (that is, when arranged on the outside), the length of the heat generating part becomes shorter and the resistance decreases, so the calorific value can be adjusted in the upward direction. Conversely, when the plug is arranged away from the end of the Al wiring 203 (that is, when arranged on the inside), the resistance value increases, so the calorific value can be adjusted in the downward direction. When the configuration of FIG. 7(d) is adopted, since the design can be changed with only one mask, the cost can be reduced when changing the calorific value of the sub-heater.

[0043] FIG. 7(e) shows a configuration in which the Poly-Si wiring of the sub-heater is intentionally cut at the bypass part. In this configuration, the above-mentioned advantages of the bypass cannot be utilized, but the degree of freedom in layout increases.

[0044] FIG. 7(f) shows a cross-section of the sub-heater with the above-mentioned Al four-layer structure. When the sub-heater 105 is driven, the current flows in through the Al wiring provided in the third layer 203b, passes through the heating area 107, and finally flows out through the Al wiring provided in the fourth layer 203a, which is the top layer.

[0045] Figure 8(a) is an enlarged plan view of the vicinity of the heater 103 on the recording element substrate 101 shown in FIG. 3. For simplicity, the sub-heater driver 108 is omitted in FIG. 8(a).

[0046] As shown in FIG. 8(a), the ink flow paths for the heater 103 and the ink supply port 106 are partitioned by a nozzle material, and one ink supply port 106 is provided on each of the left and right sides in the figure for the two heaters 103. With this configuration, ink refill after ink ejection is performed from the ink supply ports 106 on both sides, so the ejection frequency can be increased and the printing throughput can be improved. Also, in the present embodiment, as described above, since the width of the sub-heater can be reduced without decreasing the calorific value, arranging the sub-heater 105 between the heater 103 and the ink supply port 106 does not affect the ejection frequency. FIG. 8(b) is a cross-sectional view taken along the cross-section line A-A' of FIG. 8(a) (a view of the heater 103 cut in the ink flow path direction). FIG. 8(c) is a cross-sectional view taken along the cross-section line B-B' of FIG. 8(a) (a view of the sub-heater 105 cut in the longitudinal direction).

[0047] In the example shown in FIGS. 8(a) to 8(c), the sub-heater 105 is composed of a bypass portion 208 and a heating portion 209. Also, as shown in FIG. 8(b), the sub-heater 105 is provided in the lowermost layer with polysilicon wiring. Further, as shown in FIGS. 8(b) and 8(c), there are four layers of Al wiring 203, and a heater layer is laminated thereon. And those wirings are connected by plugs 206 and covered with an insulating film 202. A nozzle material is laminated on the upper layer thereof, and an ink flow path 207 and a discharge port 205 are formed. In this example, the Al wiring 203 is bypassed in the fourth layer, but it may be bypassed in other layers than the fourth layer.

[0048] As shown in Fig. 8(b), although the sub-heater 105 is away from the heater 103 from which the ink is ejected, as the position for sub-heat heating, the vicinity of the heater 103 closer to the ejected ink is ideal. Therefore, in this embodiment, a bypass portion 208 (Fig. 8(c)) is provided near the heater, and further bypassed by the upper-layer Al wiring closer to the heater 103, so that the heat generated in the heat-generating portion of the sub-heater 105 is transmitted closer to the heater. With this configuration, sub-heat heating can be performed in a portion closer to the ejected ink, the reduction in ink viscosity due to ink heating can be realized, the high-speed ink refill can be achieved accordingly, and the printing throughput can be further improved. Also, with this configuration, the ejection of high-viscosity ink becomes possible, leading to higher image quality and an increase in the degree of freedom in ink selection.

[0049] Fig. 9(a) is a plan view showing an enlarged view of the vicinity of the heater 103, similar to Fig. 8(a), but shows a case where the same film as the heater 103 is used instead of polysilicon as the sub-heater material. Fig. 9(b) is a cross-sectional view taken along the section line A-A' of Fig. 9(a) (a view of the heater 103 cut in the ink flow path direction). Fig. 9(c) is a cross-sectional view taken along the section line B-B' of Fig. 9(a) (a view of the sub-heater 105 cut in the longitudinal direction).

[0050] Generally, the resistance value of the heater material of the heater 103 for ink ejection is higher than that of polysilicon. Therefore, as shown in Fig. 9(c), compared with the case of Fig. 8(c) where polysilicon with a low resistance value is used as the sub-heater material, it is necessary to adjust the resistance value of the entire sub-heater 405 by increasing the number of bypass portions 208. However, the configuration of Fig. 9 is different from the configuration of Fig. 8 in that the sub-heater 405 is close to the heater 103 and the heat-generating portion 209 of the sub-heater 405 is arranged in the vicinity of the heater 103. Therefore, compared with the configuration of Fig. 8, the vicinity of the ejected ink can be heated, and a greater temperature rise effect can be obtained compared with Fig. 8.

[0051] Hereinafter, the data configuration for driving the sub-heater will be described with reference to Figs. 10 to 13.

[0052] FIG. 10 is a block diagram of a liquid ejection head having a head substrate 14 and a plurality of recording element substrates 101. In addition to print data Dt, a clock signal Ck and a latch signal Lt transmitted from a control board are input to each of the plurality of recording element substrates 101 through a flexible board 16. The clock signal Ck enables synchronization between two or more elements by at least one of a rising edge (transition from a low level to a high level) and a falling edge (transition from a high level to a low level) of this signal waveform. The latch signal Lt enables individual signals constituting the print data Dt to be latched by a latch circuit (not shown) at a rising edge or a falling edge of this signal waveform. Note that FIG. 10 shows a line head configuration, but the liquid ejection head of the present embodiment may of course be a serial head configuration.

[0053] FIG. 11 shows print data Dt for one transmission, and a clock signal Ck and a latch signal Lt input to the recording element substrate 101 together with this print data Dt. The print data Dt is transmitted in a predetermined unit by a serial transmission method, and the data for one transmission is called a packet or the like. Although details of the print data Dt will be described later, the print data Dt includes a plurality of information portions inf11, inf12, etc. (simply referred to as “information portion inf” when not particularly distinguished). Each information portion inf is configured to include a plurality of signals. For example, assuming that m and n are integers of 1 or more, the information portion inf11 is m-bit data including signals a(0), a(1), a(2),..., a(m), and the information portion inf12 is n-bit data including signals b(0), b(1), b(2),..., b(n). Note that the bit data is composed of a plurality of signals, and the value of each signal can also be expressed as a bit value.

[0054] In the example of FIG. 11, signals such as a(0) are sequentially input by the rising edge / falling edge of the clock signal Ck at times t0, t1, t2, etc. Then, the transmitted signals such as a(0) are latched at time tp when the latch signal Lt forms a rising edge. As described above, the print data Dt for one transmission is defined from the falling edge of a certain latch signal Lt to the rising edge of the next latch signal Lt.

[0055] FIG. 12 shows an example of the configuration of the print data Dt for one transmission. The print data Dt includes a first data part D1 and may additionally include a second data part D2. The data part D1 is composed of a plurality of information parts inf11 to inf15, and it is assumed that its data length (data size) is fixed. On the other hand, the data part D2 is configured to be able to include a plurality of additional information parts inf21 to inf28, and its data length is variable.

[0056] First, regarding the data part D1.

[0057] The information part inf11 forms one aspect (start condition) of the header of the print data Dt and constitutes notification data indicating the start of communication.

[0058] The information part inf12 indicates the presence or absence of each of the plurality of additional information parts inf21 to inf28 that may be included in the data part D2. As described above, the data length of the data part D2 is variable according to the presence or absence of each of the plurality of additional information parts inf21 to inf28.

[0059] The information part inf13 constitutes data for selecting which heater to drive. One column of each heater is assigned to each block of image data.

[0060] The information part inf14 constitutes definition data for defining the pulse waveform of the signal for driving the heater and the driving timing.

[0061] The information unit inf15 constructs diagnostic data for diagnosing whether the transmission of the print data Dt has been properly executed.

[0062] Next, the data unit D2 is processed.

[0063] In this embodiment, as the supplementary information unit, only the supplementary information unit inf21 (sub-heater selection data) is specifically defined. For inf22 and later, for example, temperature sensor selection data, test waveform selection data, ejection presence confirmation data, etc. may be applied.

[0064] In this way, the data unit D1 includes information necessary for actually executing printing or information directly related to the printing operation itself. On the other hand, the data unit D2 includes information necessary in the preparation stage before printing execution or information indirectly related to the printing operation.

[0065] FIG. 13 shows the content of the information unit inf12 which is the supplementary information specifying unit. In this embodiment, the information unit inf12 is 8-bit data. The first bit indicates the presence or absence of the supplementary information unit inf21, the second bit indicates the presence or absence of the supplementary information unit inf22, and the same applies to the third to eighth bits, each indicating the presence or absence of the corresponding supplementary information unit inf. In this embodiment, each bit takes a binary value of "0" or "1", where "0" indicates the presence or non-operation, and "1" indicates the absence or operation. For example, when the first bit is "0", it is assumed that the data unit D2 includes the supplementary information unit inf21, and when the first bit is "1", it is assumed that the data unit D2 does not include the supplementary information unit inf21.

[0066] As described above, in recent years, higher image quality and higher functionality of recording devices have been demanded, the number of heaters and sub-heaters on the recording element substrate 101 has increased, and the number of data to be transferred has also increased. Moreover, higher frequency of heater driving and increased data transfer speed are required, and the cycle of data transfer (between LT-LT) has become shorter. Therefore, in this embodiment, the print data is divided into two or more parts, and the divided print data is transferred using two transmission paths. This is one of the features of this embodiment.

[0067] FIG. 14 shows a configuration of print data in the present embodiment, in which the print data to be transferred is divided into two, and the divided print data is transmitted through two transmission lines.

[0068] As shown in FIG. 14, the image data is divided for each heater row (row A to row D). Among the divided image data, the image data for row A constitutes the information part inf131 of the first print data Dt1, and the image data for row B constitutes the information part inf132 of the first print data Dt1. Also, the image data for row C constitutes the information part inf131 of the second print data Dt2, and the image data for row D constitutes the information part inf132 of the second print data Dt2.

[0069] Also, the sub-heater selection data is also divided in half. One of the divided parts constitutes the additional information part inf21 of the first print data Dt1, and the other constitutes the additional information part inf21 of the second print data Dt2. By adopting such a data configuration, it is possible to reduce the number of data included in the print data Dt, and it is possible to cope with the high cycle of heater driving.

[0070] FIG. 15 shows the details of the sub-heater selection data that constitutes the additional information part inf21 of FIG. 14. The sub-heater selection data shown in FIG. 15 corresponds to the recording element substrate 101 shown in FIG. 3. That is, there are 20 heating areas 107 on the recording element substrate 101 of FIG. 3, and one system of sub-heaters is provided for each heating area 107. Therefore, the recording element substrate 101 has a total of 20 systems of sub-heaters. Accordingly, as shown in FIG. 15, as the sub-heater selection data 1 of Dt1, the sub-heater control signals for 10 systems of sub-heaters are transferred. Also, as the sub-heater selection data 2 of Dt2, the sub-heater control signals for the remaining 10 systems of sub-heaters are transferred. Note that since the sub-heater selection data is sent in byte units, there is a remainder in the data frame (described as "indeterminate" in the figure). For these, it does not affect the operation regardless of whether "1" or "0" is assigned.

[0071] Basically, a design in which the number of transmission paths for sending the divided Dt, the number of transmission paths for sending the divided sub-heater selection data, and the number of systems of data processing circuits for selecting sub-heaters are the same is said to be efficient in data transfer and in circuit and wiring layout. Therefore, as will be described later (see FIG. 16), the recording element substrate 101 of this example is configured to have two transmission paths for sending Dt and sub-heater selection data. However, the present embodiment is not limited to this configuration. Two or more transmission paths may be used.

[0072] FIG. 16 is a diagram showing the input mode of Dt to the recording element substrate 101 when selectively driving the sub-heater.

[0073] As shown in FIG. 16, the first print data Dt1 is input from Dt1PAD331, and the second print data Dt2 is input from Dt2PAD332. When the first print data Dt1 and the second print data Dt2 are input, a plurality of additional information portions inf (to be additional data) are input to the additional data analysis unit 330. Incidentally, the first print data Dt1 and the second print data Dt2 are generically referred to as Dt if there is no particular need to distinguish them.

[0074] After the input of the print data Dt, the additional data analysis unit 330 determines the presence or absence of sub-heater selection data by referring to the first bit of Inf12 of Dt. When the additional data analysis unit 330 determines that there is sub-heater selection data, the data (sub-heater selection data) of the additional information portion Inf21 is stored in the shift register of the data processing circuit 110. Then, at the timing when the LT signal is input, the sub-heater control signal is transferred to the sub-heater driver 108 of the sub-heater 105.

[0075] Also, a reset signal for resetting (setting to “0”) the value held in the shift register can be input from RESETPAD333. The reset signal is used at the start of driving of the recording apparatus or when an error occurs.

[0076] FIG. 17(a) is a diagram for explaining the effect when two transmission paths are arranged on the recording element substrate 101. FIG. 17(a) is a timing chart of signals and transferred print data, and the lower row (described as two transmission paths) corresponds to the configuration of the present embodiment (see FIG. 16). For reference, a timing chart corresponding to the conventional configuration is also shown in the upper row (described as one transmission path) of FIG. 17(a). As shown in FIG. 17(a), the additional information specifying unit of Dt1 (or Dt2) is sent at a certain period (specifically, several kHz to several tens of kHz). The additional data analysis unit 330 uses this additional information specifying unit to determine whether the control signal of the sub-heater is transferred to the sub-heater driver at a certain period.

[0077] As described above, the recording element substrate 101 shown in FIG. 16 has 20 sub-heaters, and since it is necessary to send a control signal for each sub-heater, the print data to be sent is 20 bits. Also, the sub-heater selection data is sent in byte units. Therefore, in the case of one transmission path, it is necessary to send the sub-heater selection data in three parts (sub-heater selection data (first byte), sub-heater selection data (second byte), sub-heater selection data (third byte)).

[0078] On the other hand, when two transmission paths are adopted as in the present embodiment, the sub-heater selection data can be sent in two parts for each transmission path (sub-heater selection data (first byte), sub-heater selection data (second byte)). Therefore, the period between the latch signals can be shortened by one byte, which contributes to higher frequencies.

[0079] Still, as shown in Fig. 17(a), it is a principle to align the number of sub-heater selection data between Dt1 and Dt2. However, as shown in Fig. 17(b), the number of sub-heater selection data may be made different between Dt1 and Dt2. In this example, since the recording element substrate 101 has 20 systems of sub-heaters, if a total of 3 bytes are secured between Dt1 and Dt2, all the sub-heater selection data can be transmitted. However, in order to achieve the effects of this embodiment, it is necessary to align the total number of data (number of bits) in each of Dt1 and Dt2. Therefore, as shown in Fig. 17(b), it is necessary to insert additional data.

[0080] In this embodiment, the number of heaters and the number of sub-heaters have been described by way of limitation. However, the number of heaters and the number of sub-heaters are not limited to those described above.

[0081] [Other Embodiments] The present disclosure can also be realized by supplying a program that realizes one or more functions of the above-described embodiment to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. Further, it can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

[0082] [Technical Features of the Present Disclosure] The present disclosure includes the following configuration.

[0083] (Configuration 1) A plurality of recording elements for discharging a liquid, the plurality of recording elements being arranged to form a recording element row, a heating element for heating the liquid, a driver for driving the heating element, a data processing circuit for controlling the driver, and a plurality of PADs for inputting signals sent to the data processing circuit from the outside, the plurality of PADs being arranged to form a PAD row, and the data processing circuit being provided with two or more between the recording element row and the PAD row. A recording element substrate characterized by this. (Configuration 2) The plurality of recording elements are arranged in a first direction to form the recording element row, the plurality of PADs are arranged in the first direction to form the PAD row, and the data processing circuit is provided with two or more between the recording element row and the PAD row in a second direction orthogonal to the first direction, the recording element substrate according to Configuration 1. (Configuration 3) The recording element substrate according to Configuration 1 or 2, further comprising a plurality of supply ports for supplying the liquid to the recording elements, the plurality of supply ports being arranged in the first direction to form a supply port row. (Configuration 4) For each recording element row, two supply port rows are provided, and the two supply port rows are provided at different positions sandwiching the recording element row in the second direction, respectively, the recording element substrate according to any one of Configurations 1 to 3. (Configuration 5) The heating element is provided between the recording element row and the supply port row in the second direction, the recording element substrate according to any one of Configurations 1 to 4. (Configuration 6) A plurality of the heating elements are provided, a heating area for each of the plurality of heating elements is determined, and the plurality of heating areas each have substantially the same layout, the recording element substrate according to any one of Configurations 1 to 5. (Configuration 7) The number of the recording elements included in each of the plurality of heating areas is equal, the recording element substrate according to any one of Configurations 1 to 6. (Configuration 8) The driver is provided so as to be one for each of the plurality of heating areas, the recording element substrate according to any one of Configurations 1 to 7. (Configuration 9) A plurality of the drivers are provided, and the wirings between each of the plurality of drivers and the data processing circuit are individual wirings, the recording element substrate according to any one of Configurations 1 to 8. (Configuration 10) The heating element is made of polysilicon, the recording element substrate according to any one of Configurations 1 to 9. (Configuration 11) The heating element has a heat generating portion made of polysilicon, a bypass portion made of aluminum, and a plug connecting the heat generating portion and the bypass portion, the recording element substrate according to any one of Configurations 1 to 10. (Configuration 12) The plug is a recording element substrate according to any one of Configurations 1 to 11, made of tungsten. (Configuration 13) The driver is arranged in a region on the side opposite to the recording element row with respect to the supply port row in the second direction, and is a recording element substrate according to any one of Configurations 1 to 12. (Configuration 14) The data processing circuit is a first data processing circuit and a second data processing circuit, and is a recording element substrate according to any one of Configurations 1 to 13. (Configuration 15) The recording element substrate according to any one of Configurations 1 to 14 further includes a first data analysis unit that analyzes data input from a first PAD, which is one of the plurality of PADs, and based on the analysis, sends the data to the first data processing circuit, and a second data analysis unit that analyzes data input from a second PAD different from the first PAD, and based on the analysis, sends the data to the second data processing circuit. (Configuration 16) The recording element substrate according to any one of Configurations 1 to 15 further includes a third PAD, which is one of the plurality of PADs, to which a reset signal is input. When the reset signal is input to the first data processing circuit, the value held in the shift register of the first data processing circuit is reset. When the reset signal is input to the second data processing circuit, the value held in the shift register of the second data processing circuit is reset. (Configuration 17) The recording element substrate has a plurality of the recording element rows, and the plurality of the recording element rows are provided at different positions in the second direction, and is a recording element substrate according to any one of Configurations 1 to 16. (Configuration 18) The shape of the recording element substrate is a rectangular shape composed of a long side and a short side, and is a recording element substrate according to any one of Configurations 1 to 17. (Configuration 19) A recording element for discharging a liquid, a heating element for heating the liquid, a driver for driving the heating element, and a data processing circuit for controlling the driver are provided. A first signal for driving the heating element and a second signal for driving the recording element are transferred using two or more transmission paths. A recording element substrate characterized by this. (Configuration 20) The recording element substrate according to Configuration 19, further comprising an analysis unit that determines whether the first signal is transferred to the heating element, and stores the first signal in the shift register of the data processing circuit based on the result of the determination. (Configuration 21) The recording element substrate according to Configuration 19 or 20, further comprising a PAD to which a signal is input from the outside. (Configuration 22) The recording element substrate according to any one of Configurations 19 to 21, wherein the number of the analysis units is equal to the number of the transmission paths, and the number of the PADs is equal to or greater than the number of the transmission paths. (Configuration 23) The data processing circuit includes a first data processing circuit and a second data processing circuit. The analysis unit includes a first analysis unit connected to the first data processing circuit and a second analysis unit connected to the second data processing circuit. The plurality of PADs include a first PAD connected to the first analysis unit, a second PAD connected to the second analysis unit, and a third PAD to which a reset signal is input. The recording element substrate according to any one of Configurations 19 to 22. (Configuration 24) The data indicating whether or not to transfer the first signal is transmitted in byte units. The recording element substrate according to any one of Configurations 19 to 23.

Explanation of Signs

[0084] 101 Recording element substrate 102 PAD 103 Heater 105 Sub - heater 108 Sub - heater driver 110 Data processing circuit

Claims

1. A plurality of recording elements for discharging a liquid, the plurality of recording elements arranged to form a recording element row, a heating element for heating the liquid, a driver for driving the heating element, a data processing circuit for controlling the driver, a plurality of PADs for inputting signals sent to the data processing circuit from the outside, the plurality of PADs arranged to form a PAD row, and having, the data processing circuit being provided with two or more between the recording element row and the PAD row, A recording element substrate characterized by the above.

2. The plurality of recording elements are arranged in a first direction to form the recording element row, the plurality of PADs are arranged in the first direction to form the PAD row, the data processing circuit is provided with two or more between the recording element row and the PAD row in a second direction orthogonal to the first direction, The recording element substrate according to claim 1.

3. A plurality of supply ports for supplying the liquid to the recording elements, further having the plurality of supply ports arranged in the first direction to form a supply port row, The recording element substrate according to claim 2.

4. Two supply port rows are provided for each recording element row, the two supply port rows are respectively provided at different positions sandwiching the recording element row in the second direction, The recording element substrate according to claim 2 or 3.

5. The heating element is provided between the recording element row and the supply port row in the second direction, The recording element substrate according to claim 4.

6. A plurality of the heating elements are provided, a heating area for each of the plurality of heating elements is determined, the plurality of heating areas each have substantially the same layout, The recording element substrate according to claim 2 or 3.

7. The number of recording elements included in each of the plurality of heating areas is equal, The recording element substrate according to claim 6.

8. The driver is provided so as to be one for each of the plurality of heating areas, The recording element substrate according to claim 7.

9. A plurality of the drivers are provided, the wiring between each of the plurality of drivers and the data processing circuit is individual wiring, The recording element substrate according to claim 8.

10. The heating element is made of polysilicon, The recording element substrate according to claim 2 or 3.

11. The heating element includes a heating portion made of polysilicon, a bypass portion made of aluminum, and a plug connecting the heating portion and the bypass portion. The recording element substrate according to claim 10.

12. The plug is made of tungsten. The recording element substrate according to claim 11.

13. The driver is arranged in a region on the side opposite to the recording element row with respect to the supply port row in the second direction. The recording element substrate according to claim 3.

14. The data processing circuit is a first data processing circuit and a second data processing circuit. The recording element substrate according to claim 2 or 3.

15. A first data analysis unit that analyzes data input from a first PAD which is one of the plurality of PADs, and based on the analysis, sends the data to the first data processing circuit; A second data analysis unit that analyzes data input from a second PAD different from the first PAD, and based on the analysis, sends the data to the second data processing circuit; It further has. The recording element substrate according to claim 14.

16. It further has a third PAD which is one of the plurality of PADs and to which a reset signal is input. When the reset signal is input to the first data processing circuit, the value held in the shift register of the first data processing circuit is reset. When the reset signal is input to the second data processing circuit, the value held in the shift register of the second data processing circuit is reset. The recording element substrate according to claim 15.

17. It has a plurality of the recording element rows. The plurality of recording element rows are respectively provided at different positions in the second direction. The recording element substrate according to claim 2 or 3.

18. The shape of the recording element substrate is a rectangular shape composed of a long side and a short side. The recording element substrate according to claim 2 or 3.

19. A recording element for discharging a liquid; A heating element for heating the liquid; A driver for driving the heating element; A data processing circuit for controlling the driver; It has. A first signal for driving the heating element and a second signal for driving the recording element are transferred using two or more transmission lines. A recording element substrate characterized by this.

20. An analysis unit that determines whether the first signal is transferred to the heating element and stores the first signal in the shift register of the data processing circuit based on the result of the determination. The recording element substrate according to claim 19. **Claim 21** Further having a PAD to which a signal is input from the outside. The recording element substrate according to claim 20. **Claim 22** The number of the analysis units is equal to the number of the transmission paths. The number of the PADs is the same as or more than the number of the transmission paths. The recording element substrate according to claim 21. **Claim 23** The data processing circuit includes a first data processing circuit and a second data processing circuit. The analysis unit includes a first analysis unit connected to the first data processing circuit and a second analysis unit connected to the second data processing circuit. The plurality of PADs include a first PAD connected to the first analysis unit, a second PAD connected to the second analysis unit, and a third PAD to which a reset signal is input. The recording element substrate according to claim 22. **Claim 24** Data indicating whether or not to transfer the first signal is transmitted in byte units. The recording element substrate according to claim 23.

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