Recording element substrate

Abstract

To provide a configuration of a recording element substrate in which wiring resistance is reduced and layout is improved as compared to a conventional one, the recording element substrate being capable of corresponding to a higher frequency.SOLUTION: An embodiment of the present invention is a recording element substrate including: a plurality of recording elements for discharging liquid, the plurality of recording elements being arrayed in a first direction to form a recording element column; a heater element for heating the liquid; a driver for driving the heater element; a data processing circuit for controlling the driver; and a plurality of PADs for receiving a signal to be transmitted to the data processing circuit input from the outside, the plurality of PADs being arrayed in the first direction to form a PAD column. At least two or more systems of the data processing circuit are provided in between the recording element column and the PAD column in a second direction orthogonal to the first direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a technique for a printing element substrate included in a printing apparatus that performs printing by ejecting liquid. [Background technology]

[0002] In a recording element substrate used in a recording device that performs recording by ejecting liquid such as ink, temperature control is performed to control the temperature of the recording element substrate in response to the demand for higher image quality and higher functionality in recent years. In addition, in order to meet this demand, there is a trend toward increasing the number of nozzles on the recording element substrate and increasing the frequency of nozzle drive.

[0003] The amount and speed of droplets discharged from the recording element substrate vary depending on the temperature, so if there is a temperature distribution in the substrate temperature, this temperature distribution directly causes unevenness in the image, resulting in reduced image quality.

[0004] Patent document 1 discloses a method for correcting the temperature distribution of a substrate by mounting a sub-heater driver in a specific area within a recording element substrate and selectively heating one or more of the areas, thereby suppressing temperature unevenness within the substrate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-213874 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the configuration of Patent Document 1 has only one data processing circuit in which data for selectively driving sub-heaters is stored based on external data input, and this configuration cannot fully meet the demands for higher image quality and higher functionality mentioned above.

[0007] In a single data processing circuit configuration, the wiring connecting the data processing circuit to the switches that drive all the sub-heaters becomes long, making the layout on the board complicated. In addition, data input to such a configuration can basically only be handled through one transmission path. In that case, if the number of sub-heaters to be driven is large, the amount of input data increases, making it impossible to handle higher frequencies.

[0008] Therefore, an object of the present disclosure is to provide a configuration of a recording element substrate that has reduced wiring resistance, an improved layout, and is compatible with higher frequencies, as compared to conventional configurations. [Means for solving the problem]

[0009] One embodiment of the present invention is a recording element substrate having a plurality of recording elements for ejecting liquid, the plurality of recording elements being arranged in a first direction to form a recording element array, a heating element for heating the liquid, a driver for driving the heating elements, a data processing circuit for controlling the driver, and a plurality of PADs to which signals to be sent to the data processing circuit are input from outside, the plurality of PADs being arranged in the first direction to form a PAD array, the data processing circuit being characterized in that at least two systems are provided between the recording element array and the PAD array in a second direction perpendicular to the first direction. Effect of the Invention

[0010] According to the present disclosure, it is possible to provide a configuration of a recording element substrate that has reduced wiring resistance, an improved layout, and is compatible with higher frequencies, as compared to conventional configurations. [Brief description of the drawings]

[0011] [Figure 1] A perspective view of a liquid ejection head [Diagram 2] Plan view of the recording element substrate [Diagram 3] FIG. 2 is a diagram showing the layout of a recording element substrate; [Figure 4] FIG. 1 shows the configuration of a sub-heater driving circuit. [Diagram 5]Block diagram when a sub-heater control signal is generated within a printing element substrate [Figure 6] A diagram showing the four-layer structure of the wiring layer in the recording element substrate. [Figure 7] A diagram showing the detailed configuration of the sub-heater [Figure 8] A diagram showing the detailed configuration around the heater (when the sub-heater material is polysilicon) [Figure 9] A diagram showing the detailed configuration around the heater (when the sub-heater material is the heater material) [Figure 10] A block diagram showing the configuration of a liquid ejection head. [Figure 11] Timing chart of data and signals input to the recording element substrate [Figure 12] A diagram showing the structure of print data (packet) Dt for one transmission [Figure 13] A diagram showing the contents of the additional information identification part (Inf12) [Figure 14] FIG. 1 is a diagram showing a configuration of print data according to an embodiment of the present invention; [Figure 15] A diagram showing the configuration of sub-heater selection data [Figure 16] FIG. 1 is a diagram for explaining data input to a recording element substrate; [Figure 17] A diagram to explain the effect of using two transmission paths DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] [First embodiment] Hereinafter, the liquid ejection head and the recording element substrate constituting the liquid ejection head in this embodiment will be described with reference to the drawings. Note that the following embodiment is not intended to limit the invention according to the claims more than necessary. In addition, although the following embodiment describes multiple features, not all of the multiple features are necessarily essential to solving the problems of the present disclosure, and the multiple features may be combined in any manner. Furthermore, in the accompanying drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions may be omitted.

[0013] Fig. 1 is a simplified perspective view showing the appearance of a liquid ejection head in this 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 in the form generally called a "line head."

[0014] Fig. 1(b) shows a liquid ejection head 100 in which two recording element substrates 101 are arranged side by side, as a configuration different from that of Fig. 1(a). This liquid ejection head is generally known as a "serial head." Note that, although this example shows a case in which the liquid ejection head has two recording element substrates, a liquid ejection head in the serial head configuration 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 this embodiment. The recording element substrate 101 in Fig. 2(a) has a parallelogram shape, and a plurality of PADs 102, which are electrical input / output points, are provided along one of the two longer sides of the parallelogram, resulting in a PAD row being formed parallel to the one side. The PADs 102 are electrodes for inputting signals to be sent to a data processing circuit (see Fig. 3), which will be 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 a plurality of PADs 102 are provided along each of the two longer sides of the parallelogram, resulting in two PAD rows being formed.

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

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

[0019] The shape of the recording element substrate is generally the shape shown in Fig. 2(a) to Fig. 2(d), but is not limited to these. For example, the shape may be a trapezoid, and the arrangement of the PAD 102 may also be various. The shape of the recording element substrate may be any rectangular shape having long and short sides.

[0020] 3 is a diagram showing the layout of the recording element substrate in this embodiment. A plurality of PADs 102 are arranged in the Y direction at the substrate end of the recording element substrate 101. These PADs 102 include signal terminals for receiving data for selecting nozzles for ejecting ink, power supply terminals, and the like.

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

[0022] The recording element substrate 101 is provided with ink supply ports 106 along the heater array for supplying ink to be ejected from the nozzles. The ink flowing in from the ink supply ports 106 is supplied to the upper portions of the heaters 103 .

[0023] An ejection port 205 (see FIG. 8(b) and FIG. 9(b)) is disposed directly above the heater 103, and a current is passed through the heater 103 at any timing to heat or bubble the ink, thereby ejecting ink droplets from the ejection port 205. Note that, although this embodiment uses a heater as an example of an element for ejecting ink, a configuration in which ink is ejected by pressurizing it using a piezoelectric element or the like may also be used.

[0024] The recording element substrate is provided with a plurality of sub-heaters 105. The sub-heaters 105 are elements for controlling the temperature of the recording element substrate 101 and the ink, and more specifically, are heat-generating elements for adjusting the temperature by heating or keeping warm. A sub-heater driver 108 is connected to the sub-heater 105, and performs ON / OFF control (control from ON to OFF or from OFF to ON) of the current flowing through the sub-heater 105. The detailed configuration around the sub-heater 105 in this embodiment will be described later with reference to FIG. 7.

[0025] The wiring between the data processing circuit 110 and the sub-heater driver 108 is routed as the data processing circuit-sub-heater driver connection wiring 111. The data processing circuit 110 stores "sub-heater control signals" which are signals for driving each of the multiple sub-heaters 105. The sub-heater control signals in this example are specifically SH_A1 to SH_A5 for row A, SH_B1 to SH_B5 for row B, SH_C1 to SH_C5 for row C, and SH_D1 to SH_D5 for row 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 multiple sub-heater drivers 108 is all individual wiring.

[0026] In this embodiment, two data processing circuits 110 are provided between the row of PADs 102 and the row of printing elements (specifically, row A), so that the printing element substrate 101 has two wiring systems. With this configuration, the layout area for individual wiring to each sub-heater is basically halved, improving the wiring layout. In addition, the wiring length can be shortened, reducing the risk of malfunction due to noise. In addition, in this example, the case where the printing 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 two, and it is sufficient that at least two or more systems of data processing circuits are 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, PAD 102a is a + power supply PAD, and PAD 102b is a GND PAD.

[0028] As shown in Fig. 6, the wiring layer of the recording element substrate of this embodiment has a four-layer structure consisting of four aluminum (hereinafter, Al) layers. In this specification, the bottom layer of these four layers is referred to as the first layer, the middle layers are referred to as the second layer, the third layer, and the top layer as the fourth layer.

[0029] The fourth layer 203a, which is the top layer, is provided with GND wiring for the heater 104 and the sub-heater 105. The third layer 203b, which is an intermediate layer closer to the top layer, is provided with + power supply wiring for the heater 104 and the sub-heater 105.

[0030] Logic wiring is provided on the second layer 203c, which is an intermediate layer near the bottom layer, and the first layer 203d, which is the bottom layer. This logic wiring is used for the data processing circuit-sub heater driver connection wiring 111 and the like. The recording element substrate of this embodiment is configured such that electricity is passed from the + power supply PAD to the sub heater via the + power supply wiring of the third layer 203b, and passes through the GND wiring of the fourth layer 203a to the PAD 102b, which is a GND PAD. These power supply PADs may also be used as power supply PADs for the heater 104 used to eject ink droplets.

[0031] A sub-heater driver 108 controlled by the sub-heater control signals SH_A1 to SH_D5 drives the sub-heater. This heats any of the 20 heating areas 107 in the recording element substrate 101. If it is desired to control the temperature in the recording element substrate more precisely than in this example (FIG. 3), 20 or more heating areas may be provided. As shown in FIG. 3, when focusing on a certain heater array (any of the arrays A to D), a plurality of ink supply ports 106 are arranged along the extension direction of the heater array to form a supply port array, and this supply port array is formed in two rows on either side of the heater array. In addition, the sub-heater driver 108 is arranged further outward of these two rows of ink supply ports in the left-right direction in the figure when the ink supply port 106 is used as a reference. In addition, the sub-heater control signals SH_A1 to SH_D5 may be directly supplied from the PAD 102, or may be converted and generated from a data signal in the recording element substrate 101.

[0032] Focusing on any one heating area, two supply port arrays are provided for each printing element array, and the sub-heater driver 108 is disposed in the area on the opposite side of the printing element array in the X direction when the relatively closer of the two supply port arrays is used as a reference.

[0033] Fig. 5 shows a block diagram of a case where 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 at the same time as the image data, the sub-heater control signal is generated in the data processing circuit 110 based on the control signal data. In this way, according to the method of Fig. 5, it is possible to control the sub-heater without having to specifically increase the number of PADs 102 for supplying the sub-heater control signal.

[0034] In FIG. 3, multiple sub-heaters 105 are arranged in the chip long side direction (Y direction in the figure), and the sub-heaters 105 are arranged between the ink supply port 106 and the heater 103 in the X direction perpendicular to the Y direction. With this arrangement, the ink near the heater 103 is heated, so that the ink to be discharged can be heated more efficiently than when the sub-heater 105 is not provided. The layout of the sub-heaters in the multiple heating areas 107 in the recording element substrate is approximately the same, and basically all of them are the same. The number of heaters 104 included in each of the multiple heating areas 107 is equal. Therefore, basically, the heat generation amount by the sub-heaters in each area is equal, and temperature control that makes the temperature distribution in the recording element substrate 101 uniform is possible. However, considering that temperature differences are likely to occur at the ends of the recording element substrate, etc., if the heat generation amount of the sub-heater is changed for each area, the layout of the sub-heater may be adjusted to adjust the temperature for each area.

[0035] Fig. 7 is a diagram showing the configuration of the sub-heater 105 in this embodiment. In detail, 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. Note that, although polysilicon (referred to as Poly-Si) is used as the sub-heater material here, the sub-heater material is not limited to polysilicon.

[0036] In FIG. 7(a), the sub-heater 105 of the heating area 107 is composed of five heat generating parts 209 and four bypass parts 208. As shown in FIG. 7(b), the bypass parts 208 are composed of Al wiring 203 and plugs 206. The resistance value of the bypass parts 208 is sufficiently small, 1 / 100 to 1 / 1000, compared to the sub-heater 105, and is estimated to be 0 ohms in this example. The bypass parts 208 can be composed of at least one of aluminum (Al), copper (Cu), gold (Au), nickel (Ni), tungsten (W), titanium (Ti), and compounds thereof.

[0037] The plug 206 can be made of, for example, tungsten (W). By connecting the Al wiring 203, which has a relatively low resistance, to the Poly-Si wiring of the sub-heater 105, the current flowing through the heating area 107 alternates between the heat generating portion 209 and the bypass portion 208, as shown by the arrow 212 in FIG. 7(b). In the sub-heater 105, most of the current flows through a portion located between adjacent Al wirings 203, and this portion functions as the heat generating portion 209 and generates heat. In this way, the Al wiring 203 is connected to both ends of any heat generating portion 209, and is connected in parallel with the portion of the sub-heater 105 other than the heat generating portion. With the above-described configuration, in the heating area 107, when the sub-heater 105 is energized, a current flows through the Al wiring 203 via the plug 206 in the middle of the path of the current flowing through the sub-heater 105. In the present embodiment, the sub-heater 105 is configured such that the heat generating parts 209 that generate heat are distributed over the heating area 107, which may make it seem as though the heating area 107 cannot be uniformly heated. However, adjacent heating parts 209 are connected by bypass parts 208 made of metal and having low thermal resistance, so that the heat generated in the heating parts 209 is diffused via the bypass parts 208, thereby heating the heating area 107 uniformly.

[0038] If it is desired to heat the heating area 107 more uniformly, the length of the bypass portion 208 may be shortened and the area may be enlarged while maintaining the ratio of the length to the width of the heat generating portion 209. However, in this case, the effect of reducing the area of ​​the circuit or the board (shrink effect) decreases.

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

[0040] FIG. 7(c) shows an example of disconnection caused by electromigration. Since the plug 206 is concentrated with current, electromigration is relatively likely to occur at the contact portion with the Al wiring 203. Usually, the circuit is designed to have a current range in which such a defect does not occur, 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 range of the heating area 107, the current is diverted to the Poly-Si wiring of the sub-heater 105, and the sub-heat function is not lost. This wiring method provides high reliability of the sub-heater drive. However, if a disconnection occurs, the resistance increases and the heat generation amount decreases. Therefore, if a disconnection occurs, it is desirable to suppress the drive of the sub-heater in the area where the disconnection occurred as much as possible.

[0041] As shown by the current path of the arrow 212, since the resistance of the sub-heater 105 is high, the current tends to flow through the Al wiring 203 with low resistance. Therefore, as shown in FIG. 7(b), even if two rows of plugs 206 are provided in the Al wiring 203 at the end, the current flows through the plugs on the front side as viewed from the heat generating part 209. However, since the sub-heater loses its sub-heating function when the power outlets on both ends of the sub-heater are disconnected, by providing two or more rows of plugs 206, even if the power outlets on the front side are disconnected, the current flows through the plugs on the back side. With this configuration, it is possible to prevent complete disconnection at both ends of the sub-heater. Since the same effect can be obtained with the Al wiring 203, two or more rows of Al wiring 203 may be arranged instead of the plugs 206 (or together with the plugs 206).

[0042] In FIG. 7(d), the length of the Al wiring is longer than that in FIG. 7(b). With this design, it becomes possible to adjust the amount of heat generated simply by changing the position of the plug, as shown by the arrow in the figure. For example, when the plug 206 is positioned closer to the end of the Al wiring 203 (i.e., when positioned on the outside), the length of the heat generating part becomes shorter and the resistance decreases, so that the amount of heat generated can be adjusted to increase. Conversely, when the plug is positioned farther from the end of the Al wiring 203 (i.e., when positioned on the inside), the resistance value increases, so that the amount of heat generated can be adjusted to decrease. When the configuration in FIG. 7(d) is adopted, the design can be changed with only one mask, so that the cost of changing the amount of heat generated by the sub-heater can be reduced.

[0043] Figure 7(e) shows a configuration in which the Poly-Si wiring of the sub-heater is cut at the bypass section. This configuration does not provide the benefits of the bypass described above, but it does increase the freedom of layout.

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

[0045] Fig. 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 the nozzle material, and one ink supply port 106 is provided on each of the left and right sides of 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 increases and printing throughput can be improved. Also, in this embodiment, as described above, the width of the sub-heater can be reduced without reducing the amount of heat generated, so even if the sub-heater 105 is placed between the heater 103 and the ink supply port 106, the ejection frequency is not affected. Fig. 8(b) is a cross-sectional view taken along line A-A' in Fig. 8(a) (a view of the heater 103 cut in the ink flow path direction), and Fig. 8(c) is a cross-sectional view taken along line B-B' in 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 (c), the sub-heater 105 is composed of a bypass section 208 and a heat generating section 209. As shown in Fig. 8(b), the sub-heater 105 is a polysilicon wiring provided in the lowest layer. As shown in Figs. 8(b) and 8(c), the Al wiring 203 has four layers, and a heater layer is laminated thereon. These wirings are connected by plugs 206 and covered with an insulating film 202. A nozzle material is laminated on the upper layer, and an ink flow path 207 and an ejection port 205 are formed. In this example, the Al wiring 203 is bypassed at the fourth layer, but it may be bypassed at a layer other than the fourth layer.

[0048] As shown in FIG. 8(b), the sub-heater 105 is away from the heater 103 from which the ink is ejected, but the ideal position for heating the sub-heater is near the heater 103, which is closer to the ink being ejected. In this embodiment, therefore, a bypass section 208 (FIG. 8(c)) is provided near the heater, and bypassed by an upper layer Al wiring closer to the heater 103, so that the heat generated in the heat generating section of the sub-heater 105 is transferred closer to the heater. This configuration enables sub-heating in a portion closer to the ink being ejected, and reduces the viscosity of the ink due to ink heating, which enables faster ink refilling and further improves the throughput of printing. This configuration also enables ejection of high-viscosity ink, which leads to higher image quality and increases the freedom of ink selection.

[0049] Fig. 9(a) is an enlarged plan view of the vicinity of the heater 103, similar to Fig. 8(a), but shows a case in which the sub-heater material is not polysilicon but the same film as the heater 103 is used. Fig. 9(b) is a cross-sectional view taken along the section line A-A' in Fig. 9(a) (a view in which the heater 103 is cut in the ink flow path direction). Fig. 9(c) is a cross-sectional view taken along the section line B-B' in Fig. 9(a) (a view in which the sub-heater 105 is cut in the longitudinal direction).

[0050] In general, 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), it is necessary to adjust the resistance value of the entire sub-heater 405 by increasing the number of bypass sections 208 compared to the case of FIG. 8(c) in which polysilicon with a low resistance value is used as the sub-heater material. However, the configuration of FIG. 9 differs from the configuration of FIG. 8 in that the sub-heater 405 is closer to the heater 103 and the heat generating section 209 of the sub-heater 405 is disposed in the vicinity of the heater 103. Therefore, the vicinity of the ejected ink can be heated more than the configuration of FIG. 8, and a greater temperature rise effect can be obtained compared to FIG. 8.

[0051] The data configuration for driving the sub-heaters will be described below with reference to FIGS.

[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 the print data Dt, a clock signal Ck and a latch signal Lt transmitted from the control substrate are input to each of the plurality of recording element substrates 101 through the flexible substrate 16. The clock signal Ck enables synchronization between two or more elements by at least one of the rising edge (transition from low level to high level) and the falling edge (transition from high level to 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) by the rising edge or the falling edge of this signal waveform. Although FIG. 10 shows a line head configuration, the liquid ejection head of this embodiment may of course be a serial head configuration.

[0053] FIG. 11 shows print data Dt for one transmission, as well as a clock signal Ck and a latch signal Lt input to the recording element substrate 101 together with the 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. The print data Dt will be described in detail later, but it includes a plurality of information sections inf11, inf12, etc. (when no particular distinction is made, it will be simply referred to as "information section inf"), and each information section inf includes a plurality of signals. For example, where m and n are integers of 1 or more, the information section inf11 is m-bit data including signals a(0), a(1), a(2),..., a(m), and the information section inf12 is n-bit data including signals b(0), b(1), b(2),..., b(n). Note that bit data is composed of a plurality of signals, and the value of each signal can also be expressed as a bit value.

[0054] 11, the signals a(0) etc. are input in sequence by the rising edges / falling edges of the clock signal Ck at times t0, t1, t2 etc., and then the transmitted signals a(0) etc. are latched at time tp when the latch signal Lt forms a rising edge. As described above, one transmission of print data Dt is defined from the falling edge of one latch signal Lt to the rising edge of the next latch signal Lt.

[0055] 12 shows an example of the configuration of print data Dt for one transmission. The print data Dt includes a first data section D1, and may also include a second data section D2. The data section D1 includes multiple information sections inf11-inf15, and its data length (data size) is fixed. In contrast, the data section D2 is configured to be able to include multiple additional information sections inf21-inf28, and its data length is variable.

[0056] First, the data section D1 will be described.

[0057] The information section 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 section inf12 indicates the presence or absence of each of the multiple additional information sections inf21-inf28 that may be included in the data section D2. As described above, the data length of the data section D2 is variable depending on the presence or absence of each of the multiple additional information sections inf21-inf28.

[0059] The information section inf13 configures data for selecting which heaters to drive. Each image data block is assigned to one row of heaters.

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

[0061] The information section inf15 constitutes diagnostic data for diagnosing whether or not the transmission of the print data Dt has been properly executed.

[0062] Next, the data section D2 will be described.

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

[0064] Thus, data section D1 contains information required for the actual printing or information directly related to the printing operation itself, while data section D2 contains information required in the preparation stage before printing or information indirectly related to the printing operation.

[0065] FIG. 13 shows the contents of the information section inf12, which is the incidental information identification section. In this embodiment, the information section inf12 is 8-bit data. The first bit indicates the presence or absence of the incidental information section inf21, the second bit indicates the presence or absence of the incidental information section inf22, and the third to eighth bits similarly indicate the presence or absence of the corresponding incidental information section inf. In this embodiment, each bit takes two values, "0" or "1", where "0" indicates the presence or absence of operation, and "1" indicates the absence or operation. For example, when the first bit is "0", the data section D2 includes the incidental information section inf21, and when the first bit is "1", the data section D2 does not include the incidental information section inf21.

[0066] As mentioned above, in recent years, there has been a demand for higher image quality and higher functionality in printing apparatuses, and the number of heaters and sub-heaters on the printing element substrate 101 has increased, leading to an increase in the amount of data to be transferred. In addition, there is a demand for higher frequency heater drive and faster data transfer speeds, and the data transfer period (LT-LT) is becoming shorter. For this reason, in this embodiment, the print data is divided into two or more pieces, 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 this embodiment in which print data to be transferred is divided into two pieces and the divided print data are transmitted over two transmission paths.

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

[0069] The sub-heater selection data is also split in half, with one half forming the additional information section inf21 of the first print data Dt1 and the other half forming the additional information section inf21 of the second print data Dt2. By configuring the data in this way, it is possible to reduce the amount of data included in the print data Dt and to accommodate faster heater drive cycles.

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

[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 for the data processing circuit for selecting the sub-heaters are the same is considered to provide good data transfer efficiency and circuit / wiring layout efficiency. Therefore, the recording element substrate 101 of this example is configured to have two transmission paths for sending Dt and the sub-heater selection data, as described later (see FIG. 16). However, this embodiment is not limited to this configuration. There may be two or more transmission paths.

[0072] FIG. 16 is a diagram showing an input state of Dt to the printing element substrate 101 when the sub-heaters are selectively driven.

[0073] 16, the first print data Dt1 is input from the Dt1PAD 331, and the second print data Dt2 is input from the Dt2PAD 332. When the first print data Dt1 and the second print data Dt2 are input, a plurality of additional information sections inf (referred to as additional data) are input to the additional data analysis section 330. Note that the first print data Dt1 and the second print data Dt2 will be collectively referred to as Dt unless there is a need to distinguish between them.

[0074] After the print data Dt is input, the additional data analysis unit 330 determines whether or not sub-heater selection data is present by referring to the first bit of Inf12 of Dt. If the additional data analysis unit 330 determines that sub-heater selection data is present, the data in the additional information section Inf21 (sub-heater selection data) is stored in the shift register of the data processing circuit 110. Thereafter, 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 that resets (to "0") the value held in the shift register can be input from a RESETPAD 333. The reset signal is used when the printing apparatus starts to operate 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 part (described as two transmission paths) corresponds to the configuration of this embodiment (see FIG. 16). For reference, the upper part (described as one transmission path) of FIG. 17(a) also shows a timing chart corresponding to a conventional configuration. As shown in FIG. 17(a), the additional information identification part of Dt1 (or Dt2) is sent at a constant cycle (specifically, several kHz to several tens of kHz). The additional data analysis unit 330 uses this additional information identification part to determine whether a control signal for the sub-heater is transferred to the sub-heater driver at a constant cycle.

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

[0078] In contrast, when two transmission paths are used as in this embodiment, the sub-heater selection data can be sent twice via each transmission path (sub-heater selection data (first byte), sub-heater selection data (second byte)). This allows the period between latch signals to be shortened by one byte, which contributes to higher frequencies.

[0079] As shown in FIG. 17(a), the number of sub-heater selection data is generally the same for Dt1 and Dt2, but as shown in FIG. 17(b), the number of sub-heater selection data may be different for Dt1 and Dt2. In this example, since the recording element substrate 101 has 20 sub-heaters, if a total of 3 bytes is secured for Dt1 and Dt2, all the sub-heater selection data can be transmitted. However, in order to achieve the effect of this embodiment, it is necessary to match the total number of data (number of bits) for Dt1 and Dt2, so that it is necessary to insert additional data as shown in FIG. 17(b).

[0080] In this embodiment, the number of heaters and the number of sub-heaters are limited, but the number of heaters and the number of sub-heaters are not limited to the above.

[0081] [Other embodiments] The present disclosure can also be realized by a process in which a program for implementing one or more functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that implements one or more functions.

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

[0083] (Configuration 1) A recording element substrate comprising: a plurality of recording elements for ejecting liquid, the plurality of recording elements being arranged in a first direction to form a recording element array; a heating element for heating the liquid; a driver for driving the heating elements; a data processing circuit for controlling the driver; and a plurality of PADs to which signals to be sent to the data processing circuit are input from the outside, the plurality of PADs being arranged in the first direction to form a PAD array, the data processing circuit being provided in at least two systems between the recording element array and the PAD array in a second direction perpendicular to the first direction. (Configuration 2) The recording element substrate according to configuration 1, further comprising a plurality of supply ports through which the liquid is supplied toward the recording element, the plurality of supply ports being arranged in the first direction to form a supply port row. (Configuration 3) A recording element substrate according to configuration 1 or 2, wherein two supply port arrays are provided for each recording element array, and the two supply port arrays are each provided at different positions in the second direction on either side of the recording element array. (Configuration 4) The recording element substrate according to any one of configurations 1 to 3, wherein the heat generating elements are provided between the recording element array and the supply port array in the second direction. (Configuration 5) A recording element substrate according to any one of configurations 1 to 4, wherein a plurality of the heat generating elements are provided, a heating area is determined for each of the plurality of the heat generating elements, and each of the plurality of the heating areas has approximately the same layout. (Configuration 6) The recording element substrate according to any one of configurations 1 to 5, wherein the number of the recording elements included in each of the plurality of heating areas is equal. (Configuration 7) The recording element substrate according to any one of configurations 1 to 6, wherein the driver is provided so that one driver corresponds to each of the plurality of heating areas. (Configuration 8) The recording element substrate according to any one of configurations 1 to 7, wherein a plurality of the drivers are provided, and wiring between each of the plurality of drivers and the data processing circuit is individual wiring. (Configuration 9) The recording element substrate according to any one of configurations 1 to 8, wherein the heat generating elements are made of polysilicon. (Configuration 10) The recording element substrate according to any one of configurations 1 to 9, wherein the heat generating 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. (Configuration 11) The recording element substrate according to any one of configurations 1 to 10, wherein the plug is made of tungsten. (Configuration 12) A recording element substrate described in any one of configurations 1 to 11, wherein the driver is arranged in an area on the opposite side of the recording element array in the second direction when the supply port array is used as a reference. (Configuration 13) The recording element substrate according to any one of configurations 1 to 12, wherein the data processing circuit is a first data processing circuit and a second data processing circuit. (Configuration 14) A recording element substrate described in any one of configurations 1 to 13, further comprising: a first data analysis unit that analyzes data input from a first PAD that is one of the multiple PADs and sends data to a first data processing circuit based on the analysis; and a second data analysis unit that analyzes data input from a second PAD different from the first PAD and sends data to a second data processing circuit based on the analysis. (Configuration 15) A recording element substrate described in any one of configurations 1 to 14, further comprising a third PAD which is one of the plurality of PADs, the third PAD to which a reset signal is input, and when the reset signal is input to the first data processing circuit, a value held in a shift register of the first data processing circuit is reset, and when the reset signal is input to the second data processing circuit, a value held in a shift register of the second data processing circuit is reset. (Configuration 16) The recording element substrate according to any one of configurations 1 to 15, further comprising a plurality of the recording element arrays, each of the plurality of recording element arrays being provided at a different position in the second direction. (Configuration 17) The recording element substrate according to any one of configurations 1 to 16, wherein the recording element substrate has a rectangular shape having long sides and short sides. (Configuration 18) A recording element for ejecting liquid, a heating element for heating the liquid, a driver for driving the heating element, a data processing circuit for controlling the driver, and an analysis unit for determining whether a first signal for driving the heating element is transferred to the heating element and, based on a result of the determination, storing the first signal in a shift register of the data processing circuit; a signal for driving the recording element is transferred at a constant cycle, the analysis unit determines at the constant cycle whether the first signal is to be transferred, and the first signal and a second signal for driving the recording element are transferred using at least two transmission paths. (Configuration 19) The recording element substrate according to configuration 18, further comprising a PAD to which a signal is input from the outside. (Configuration 20) The recording element substrate according to configuration 18 or 19, wherein the number of the analysis sections 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 21) A recording element substrate described in any one of configurations 18 to 20, wherein 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, and the multiple 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. (Configuration 22) The recording element substrate according to any one of configurations 18 to 21, wherein the data indicating whether or not to transfer the first signal is transmitted in byte units. (Configuration 23) The recording element substrate according to any one of configurations 18 to 22, wherein the certain period is several kHz to several tens of kHz. [Explanation of symbols]

[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 ejecting liquid, the plurality of recording elements being arranged in a first direction to form a recording element array; 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 to which signals to be sent to the data processing circuit are input from an external source, the plurality of PADs being arranged in the first direction to form a PAD row; having the data processing circuit is provided in at least two systems between the recording element array and the PAD array in a second direction perpendicular to the first direction; A recording element substrate comprising:

2. a plurality of supply ports through which the liquid is supplied toward the recording element, the plurality of supply ports being arranged in the first direction to form a supply port row; The recording element substrate according to claim 1 .

3. Two supply port arrays are provided for each of the recording element arrays, the two supply port arrays are provided at different positions in the second direction with the printing element array therebetween, 3. The recording element substrate according to claim 1.

4. the heating element is provided between the recording element array and the supply port array in the second direction, The recording element substrate according to claim 3 .

5. A plurality of the heating elements are provided, A heating area for each of the plurality of heating elements is determined, Each of the plurality of heating areas has a substantially identical layout.

3. The recording element substrate according to claim 1.

6. the number of the recording elements included in each of the plurality of heating areas is equal; The recording element substrate according to claim 5 .

7. The driver is provided for each of the plurality of heating areas. The recording element substrate according to claim 6 .

8. A plurality of said drivers are provided, Wiring between each of the plurality of drivers and the data processing circuit is individual wiring. The recording element substrate according to claim 7 .

9. The heating element is made of polysilicon.

3. The recording element substrate according to claim 1.

10. The heat generating 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 claim 9 .

11. The plug is made of tungsten. The recording element substrate according to claim 10.

12. the driver is disposed in an area on the opposite side to the recording element array with respect to the supply port array in the second direction; The recording element substrate according to claim 2 .

13. The data processing circuit is a first data processing circuit and a second data processing circuit.

3. The recording element substrate according to claim 1.

14. a first data analysis unit that analyzes data input from a first PAD that is one of the plurality of PADs and transmits data to a first data processing circuit based on the analysis; a second data analysis unit that analyzes data input from a second PAD different from the first PAD and transmits the data to a second data processing circuit based on the analysis; Further comprising The recording element substrate according to claim 13.

15. The third pad is one of the plurality of pads, and a reset signal is input to the third pad. When the reset signal is input to the first data processing circuit, a value held in a shift register of the first data processing circuit is reset, When the reset signal is input to the second data processing circuit, a value held in a shift register of the second data processing circuit is reset. The recording element substrate according to claim 14.

16. A recording element array includes a plurality of the recording element arrays, the plurality of recording element arrays are provided at different positions in the second direction, 3. The recording element substrate according to claim 1.

17. The shape of the recording element substrate is a rectangle having long sides and short sides.

3. The recording element substrate according to claim 1.

18. A recording element for ejecting liquid; a heating element for heating the liquid; A driver for driving the heating element; A data processing circuit for controlling the driver; an analysis unit that determines whether a first signal for driving the heating element is transferred to the heating element, and stores the first signal in a shift register of the data processing circuit based on a result of the determination; having The signal for driving the recording element is transferred at a constant cycle. The analysis unit determines whether the first signal is transferred at the certain period, the first signal and the second signal for driving the recording element are transferred using at least two transmission paths; A recording element substrate comprising:

19. The device further includes a PAD to which a signal is input from the outside. The recording element substrate according to claim 18.

20. The number of the analysis units is equal to the number of the transmission paths, The number of the PADs is equal to or greater than the number of the transmission lines. The recording element substrate according to claim 19.

21. 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 20.

22. The data indicating whether to transfer the first signal is transmitted in units of bytes. The recording element substrate according to claim 21 .

23. The constant period is several kHz to several tens of kHz. The recording element substrate according to claim 18 .

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