JP2019006108A - Recording apparatus and recording head substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the number of simultaneous drive heaters for ink ejection due to high speed printing, and noise is added to a temperature detection voltage, making high-precision temperature detection difficult. A recording head board is arranged on a recording head board, a recording element, a driving element, an application circuit, a ground wiring to which the application circuit is connected, and the ground wiring and a cathode side via a resistor. A plurality of connected temperature sensors, a resistor connected between the cathode side of the plurality of temperature sensors and the ground wiring, and any of the plurality of temperature sensors on the anode side of the plurality of temperature sensors. By the first selection circuit for selecting, a second selection circuit for selecting any of the plurality of temperature sensors on the cathode side of the plurality of temperature sensors, and the first selection circuit. It is provided with an output unit for outputting the voltage on the anode side of the selected temperature sensor and the voltage on the cathode side of the temperature sensor selected by the second selection circuit. [Selection diagram] Fig. 5

Description

  The present invention relates to a recording apparatus and a recording head substrate.

  2. Description of the Related Art Recording apparatuses that record information such as desired characters and images on a sheet-like recording medium such as paper or film are widely used. As a configuration of a recording head used in such a recording apparatus, there is an ink jet recording head that performs recording using thermal energy. An ink jet recording head has a heater connected to a discharge port that discharges ink droplets as a recording element, generates heat by applying current to the heater, and discharges ink droplets by boiling the ink film. Make a record. In such a recording head, it is easy to arrange a large number of discharge ports and heaters at a high density, and thereby a high-definition recorded image can be obtained.

JP 2012-000954 A

  In the recording head substrate, the amount of ink droplets discharged and the discharge speed vary depending on the temperature. For this reason, when a temperature distribution occurs on the substrate, the temperature distribution becomes uneven as it is, and the image quality deteriorates.

  Therefore, in order to correct the temperature unevenness of the substrate, the temperature of multiple points in the substrate is acquired, and temperature control is performed so that the temperature in the substrate is made constant. In order to acquire multipoint temperatures, Patent Document 1 discloses a circuit configuration in which a selection circuit is provided in a substrate, and multipoint temperatures can be acquired with a minimum number of terminals. With this configuration, it is possible to correct multi-point temperature unevenness and achieve high image quality at low cost. However, as the throughput of recording operations using the substrate (recording head) of the recent recording head has further improved, the number of simultaneously driven heaters for ink ejection has increased. It's getting difficult to get. Even when one heater is driven, a similar problem may occur. Reduction of the influence of this noise is required.

  In order to solve the above problems, the present invention has the following configuration. That is, a recording apparatus, a recording head substrate having a recording element for recording an image, a driving element for driving the recording element, an application circuit for applying a driving signal to the driving element, and the application A ground wiring to which a circuit is connected; a plurality of temperature sensors for detecting a temperature related to the recording head substrate; the ground wiring and the cathode side being connected via a resistor; and anodes of the plurality of temperature sensors A first selection circuit for selecting one of the plurality of temperature sensors on the side, and a selection circuit for selecting one of the plurality of temperature sensors on the cathode side of the plurality of temperature sensors. A second selection circuit; a voltage on the anode side of the temperature sensor selected by the first selection circuit; and a cathode of the temperature sensor selected by the second selection circuit. Comprising a temperature signal output circuit for outputting a temperature signal according to a difference between the voltage side.

  According to the present invention, it is possible to suppress the influence of noise when detecting temperatures at multiple points in a recording head.

The figure which shows the example of the circuit structure which concerns on 1st embodiment. The figure which shows the structural example of the conventional temperature detection circuit for a comparison. The figure for demonstrating the voltage / current waveform in the circuit structure concerning 1st embodiment. The figure for demonstrating the voltage / current waveform in the conventional circuit structure for a comparison. FIG. 3 is a plan / sectional view of the PNP temperature detection diode according to the first embodiment. FIG. 6 is a plan / sectional view of a conventional PNP temperature detection diode for comparison. The figure which shows the example of the circuit structure which concerns on 2nd embodiment. FIG. 6 is a plan / sectional view of an NPN temperature detection diode according to a second embodiment.

<First embodiment>
FIG. 1 is a diagram showing an example of a circuit configuration of a recording head substrate according to the first embodiment of the present invention. FIG. 2 is a diagram showing an example of a circuit configuration of a conventional recording head substrate as a comparison target. FIG. 3 is a diagram for explaining voltage / current waveforms in an example of the circuit configuration of the recording head substrate according to the first embodiment of the invention. FIG. 4 is a diagram for explaining voltage / current waveforms in the example of the circuit configuration of FIG. 2 shown as a comparison target. FIG. 5 shows diodes (hereinafter referred to as temperature detection DI) 104-1, 104-2, and 104-3 (hereinafter collectively referred to as temperature detection sensors) according to the first embodiment of the present invention. FIG. 104 is a plan / cross-sectional view and a connection diagram. Hereinafter, the configuration according to the present embodiment will be described with reference to these drawings.

  The recording head substrate 101 and the electric substrate 121 are electrically connected via the flexible wiring 120. Here, the electric board 121 will be described as being provided on the recording apparatus main body side. Further, on the recording apparatus main body side, a control signal for controlling various circuits provided on the recording head substrate 101 and a signal corresponding to image data for image formation are output to the recording head substrate 101. It is assumed that a part is provided. Here, description will be made assuming that the control unit 127 outputs various signals to the recording head substrate 101.

  First, a conventional configuration example and problems for comparison will be described with reference to FIGS. The recording head substrate 101 heats the heater 102 by causing a heater current 202 to flow through the heater 102 and causes ink to be foamed and discharged. Here, in order to simplify the description, the description will be focused on the configuration around one heater, but the recording head substrate 101 is provided with a plurality of heaters for image formation. And In this case, the plurality of heaters perform time-division driving at a predetermined timing. VH110 indicates a power supply for flowing the heater current 202, and supplies a high voltage of about 10 to 30V. On the negative side as a pair, GNDH 111 as a ground wiring is provided. VHT 112 indicates a power supply, supplies a low voltage of about 3 to 5 V, and is used as a logic drive or a drive voltage of the driver transistor 103. The negative side of the pair is connected to the ground wiring, and this ground wiring is connected to the terminal VSS205.

  In order to drive the heater, a heat signal 201 which is a drive signal in the logic circuit 210 based on a signal from the control unit 127 provided on the electric substrate 121 side at the gate (G) of the driver transistor 103 which is a drive element. And the heat signal 201 (FIG. 3) is applied via the buffer 109. The buffer 109 operates as an application circuit for the heat signal 201 to the driver transistor 103. At this time, as shown in FIG. 2, a charge current 203 and a sink current 204 flow through the gate capacitance at the ON / OFF transition. At the ON transition time, the charge current 203 flows from the VHT 112 to the gate via the buffer 109 to charge the charge. At that time, the same charge current 203 and the same current flow to the GNDH 111 on the reverse terminal side of the capacitor due to the charge transfer between the gate capacitors. Similarly, a current flows through the path from the VH 110 to the terminal VSS 205 with respect to the sink current 204 at the OFF transition. The print head substrate 101 is provided with a driver transistor 103 and a buffer 109 corresponding to the heater 102. The recording head substrate 101 is provided with a plurality of driver transistors and a plurality of buffers 109.

  The recording head substrate 101 is designed so that heat noise does not affect the logic power supply system as much as possible by providing a high voltage power supply system and a low voltage logic power supply system separately. However, regarding the gate drive current of the driver transistor 103, current flows back and forth between both power supply pairs via the gate capacitance as described above. As a result, a voltage affected by the common mode noise as shown by the voltage waveform VSS305 in FIG. 4 is output to the electric substrate 121 side connected to the terminal VSS205. This noise is generated when a high-frequency current such as the charge current 203 and the sink current 204 flows through the flexible wiring 120. The noise level is mainly determined by the number of driver transistors 103 (gate force / sink current value) that are driven simultaneously and the parasitic inductance of the flexible wiring 120.

  A plurality of temperature detection DIs 104 provided on the recording head substrate 101 are selected by the MUXs 105 and 106 functioning as selection circuits, and an analog voltage depending on the temperature is generated by flowing a DI current 113. This analog voltage is output to the electric board 121 from the output unit (terminal DIK 206, terminal DIA_MON 207). The plurality of temperature detection DIs 104 are arranged at different positions on the recording head substrate 101. In other words, the plurality of temperature detection DIs 104 are arranged so as to be able to detect temperatures at different positions of the recording head substrate 101. As described above, the control signal (external signal) is input to the recording head substrate 101 from the electric substrate 121, and selection by the MUXs 105 and 106 is performed based on this control signal. The analog voltage output from the recording head substrate 101 is amplified by a signal amplification circuit 124 provided on the electric substrate 121 side, and is digitally converted by an AD converter (hereinafter referred to as ADC) 122 that functions as a temperature signal output circuit at an arbitrary timing. Then, the temperature data based on the detected temperature signal is transferred to a main body ASIC (not shown) that functions as a control unit for the recording head substrate 101. The main body ASIC controls the pulse width of the heat signal based on, for example, temperature data. The control unit 127 that outputs various signals may include a main body ASIC (not shown) as a part thereof. The MUX 106 is connected to the terminal (input unit) on the anode side of the current of the temperature detection DI 104.

  As shown in FIGS. 2 and 4, in the conventional configuration for comparison, the DI current 113 is input from the terminal DIA 208 of the recording head substrate 101 and flows to the terminal DIK 206. This is a design concept in which the terminal DIK 206 and the terminal VSS 205 are separated via the substrate resistor 108 so that the noise generated on the terminal VSS 205 side is not affected as much as possible on the terminal DIK 206 side. . However, when the number of temperature detection DIs 104 increases for multipoint temperature detection, the resistance between the terminal DIK 206 and the terminal VSS 205 decreases due to the parallelization of the substrate resistance 108. As a result, the sink current 204 flows to the terminal DIK 206 side and is greatly affected by the noise in temperature detection. If the voltage is acquired by the ADC 122 on the electric substrate 121 side after waiting for the noise to converge, a high-accuracy temperature can be obtained, but the throughput is reduced by the waiting time. On the other hand, if priority is given to throughput, the influence of the noise described above remains and the detection accuracy with respect to temperature decreases.

  In the circuit configuration according to the present embodiment, as shown in FIG. 5B, the temperature detection DI 104 uses a diode connection configuration in which the base 502 and the collector 503 of the PNP transistor are short-circuited. The temperature voltage is generated between the emitter (E) and the base (B), and a current obtained by amplifying the base current flows between the emitter (E) and the collector (C). As described above, it is possible to flow a larger amount of current in the diode connection configuration using the PNP transistor than in the simple PN configuration, and the current noise resistance is remarkably increased.

  FIG. 5 shows a plan / sectional view of the temperature test DI 104 according to the present embodiment. FIG. 5B is a cross-sectional view taken along the line A-A ′ shown in FIG. Each electrode of the PNP transistor is composed of a plug 403 and a high impurity concentration region doped with silicon and having a relatively low resistance. The emitter 501, the collector 503, and the sub-contact 504 function as p high impurity concentration regions P + 403, and the base 405 functions as an n high impurity concentration region N + 405. A PN-structured diode is formed by P + 403 and N-404 of the emitter 501, and a base 502 is formed as an N-side electrode. A PNP transistor is formed by contacting a P-type silicon substrate 401, and a collector 503 is formed as a P-type electrode. A sub contact 504 is disposed on the outer periphery of the collector 503. The sub-contact 504 is generally a transistor for reducing the potential of the P-402 or the P-type silicon substrate 401 to 0 V through the high impurity concentration region P + 403 and ensuring the ground level of the circuit power supply so as to stabilize the circuit. Place in the vicinity.

  In the conventional configuration for comparison, as shown in FIG. 6, the current flowing out from the emitter 501 flows to the collector 503 (terminal DIK 206 side). On the other hand, in the present embodiment, the current flows to the sub-contact 504 via the substrate resistor 108 instead of the collector 503. As a result, the voltage value at the terminal DIK 206 is made higher than the GND 126 by a fixed voltage. The substrate resistance 108 is a Si substrate resistance having a relatively low impurity concentration of p formed by P-402 configured between the collector 503 of the PNP transistor and the sub-contact 504. As described above, the sub-contact 504 is generally used to stabilize the substrate voltage at the GND potential. For this reason, the sub-contact 504 is not used as a circuit current path. On the other hand, in this embodiment, the sub-contact 504 is used as an electrode of the substrate resistor 108 and used as a current path. Further, in general, P + 403 is used by the sub-contact 504 so as to be at the GND potential. However, in this embodiment, the potentials of P + 403 and nearby P-402 are set to a voltage higher than the GND potential.

  Next, a first embodiment of the present invention will be described with reference to FIG. The same contents as the conventional configuration for comparison will be briefly described. Each of the plurality of temperature detection DIs 104 has a pair of anode 505 and cathode 506. The substrate resistor 108 is connected between the temperature detection DI 104 and the terminal VSS 205. The cathode 506 of the temperature test DI 104 is connected to the substrate resistor 108. The MUX 105 selects a connection destination of the terminal DIA208. That is, the MUX 105 operates to select a supply destination of power applied from a power supply source from the plurality of temperature detection DIs 104. The MUX 106 selects a connection destination of the terminal DIA_MON 207. The MUX 107 selects a connection destination of the terminal DIK206. That is, the MUXs 106 and 107 operate so as to select a temperature detection DI to be used when detecting the temperature from the plurality of temperature detection DIs 104. The anode 505 of the temperature test DI 104 is connected to the MUXs 105 and 106. Therefore, the DI current 113 from the constant current source 123 is selectively energized to the temperature detection DI 104 by the MUX 105. The potential of the anode 505 of the temperature test DI 104 is selectively output by the MUX 106 to the electric substrate 121 side located outside the recording head substrate 101 via the terminal DIA_MON 207. A connection portion between the cathode 506 of the temperature detection DI 104 and the substrate resistance 108 is connected to the MUX 107. By the selection by the MUX 107, the potential of the cathode 506 of the temperature test DI 104 is output to the electric board 121 side via the terminal DIK 206. That is, the DI current 113 flows through one temperature detection DI 104 selected by the MUX 105. As a result, the potential difference (voltage difference) between the anode 505 and the cathode 506 at both ends of the temperature detection DI 104 selected by the MUX 106 and MUX 107 is output as a potential difference between the terminal DIA_MON 207 and the terminal DIK 206. In the present embodiment, each of the MUXs 105, 106, and 107 selects a connection destination in accordance with a control signal from the control unit 127 provided on the electric board 121 side. In the present embodiment, the MUXs 105, 106, and 107 operate in conjunction with each other in order to select one temperature test DI 104. However, the present invention is not limited to this configuration. For example, the MUX 105 may operate based on a control signal different from that of the MUXs 106 and 107.

  The signal amplifying circuit 125 on the electric board 121 in FIG. 1 has a circuit configuration that operates as a differential circuit that receives the potential difference between the voltage of the terminal DIA_MON 207 and the voltage of the terminal DIK 206. Both inputs of the signal amplifier circuit 125 connected to the terminal DIA_MON 207 and the terminal DIK 206 are in a Hi-Z (high impedance) state. Further, the MUX 107 separates the connection between the cathode terminal of the temperature detection DI 104 and the terminal DIK 206, which is common in the configuration shown in FIG. 2, and selectively connects the wiring for monitoring the voltage to the cathode terminal (output unit). doing. In other words, the MUX 107 is provided so that connection with any one of the collectors of each of the temperature detection DIs 104 can be selected. In other words, the MUX 107 is connected so as to monitor the voltage value at the connection portion between the cathode terminal of the temperature detection DI 104 and the substrate resistance 108. With such a configuration, as shown in FIG. 3, the voltage value from the terminal DIK 206 can be increased by a fixed voltage with respect to the GND 126.

  As shown in FIG. 4 as a conventional example for comparison, when it is assumed that the voltage at the terminal DIK 206 outputs a negative value due to the influence of noise, the signal amplifier circuit needs to expand the voltage input range to the negative side. was there. For this purpose, it is necessary to provide a separate negative power source or use an amplifier that supports negative voltage input. However, in the configuration according to the present embodiment, since the voltage is not output as a negative value, it is possible to configure the signal amplification circuit 125 with a single power supply general-purpose amplifier, which can greatly reduce the cost. .

  In order to increase the voltage from the target voltage by a fixed voltage in this way, there is a method in which a resistance element is separately provided between the cathode 506 in the path of the DI current 113 and the ground. However, in the present embodiment, as described above, since the current flows through the sub-contact 504, it can be realized without a special resistance element and a substrate space for resistance.

As described above with reference to FIG. 3, since both inputs of the signal amplifier circuit 125 are in the Hi-Z state, the noise that affects the voltage waveform VSS 305 remains as it is, the voltage waveform DIA_MON 307 output from the terminal DIK_MON 207, and the terminal DIK 206. Is superimposed on both voltages of the voltage waveform DIK 306 output from. The output of the signal amplifier circuit 125 is
Output voltage = (DIA_MON−DIK) × amplification factor. That is, the analog temperature voltage from which the noise component has been canceled is output to the ADC 122. As a result, it is possible to achieve both improvement in temperature detection accuracy and improvement in throughput.

  In the present embodiment, an example in which the signal amplifying circuit 125, the ADC 122, and the constant current source 123 are mounted on the electric board 121 is shown. However, the present invention is not limited to this configuration, and these circuits may be mounted in the recording head substrate 101.

  In addition to the above-described embodiment, instead of the signal amplifier circuit 125, the digital signal amplifier circuit may input a digital voltage and output a digital temperature voltage with a noise component canceled. For example, an AD converter is provided on the recording head substrate 101. This AD converter inputs an analog voltage of the temperature detection DI 104 and converts it into a digital voltage. The AD converter is configured to output a digital voltage to the terminal DIA_MON 207 and the terminal DIK 206. With this configuration, the signal amplifier circuit 125 inputs a digital voltage via the terminal DIA_MON 207 and the terminal DIK 206.

  In the configuration example of FIG. 5, the sub-contact 504 is disposed so as to surround the temperature detection DI 104, but may be disposed at a further distant position. For example, if the sub-contact 504 is not provided around the temperature detection DI 104 but a current is passed to a sub-contact such as a logic circuit far away from the temperature detection DI 104, the substrate resistance value increases and the noise margin at the terminal DIK also increases. . The resistance value varies greatly depending on the impurity concentration of P-402. For example, when the sub-contact 504 is separated by about 40 μm, the resistance is about 200Ω. Therefore, for example, the distance between the collector and the subconductor can be 40 μm or more. When the diode current is 0.2 mA, the voltage at the terminal DIK 206 is increased by about 40 mV. Therefore, if the amplitude is noise of about −40 mV, the signal amplification circuit 125 can cope with a single power source.

  The resistance corresponding to the substrate resistance 108 is constituted by polysilicon or polycrystalline silicon (Poly-Si), a resistance of the same material as the recording element, a Si substrate resistance, and the like.

<Second Embodiment>
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 7 shows a configuration example of the recording head substrate according to the present embodiment. FIG. 8 shows a plan layout and a cross-sectional view of the temperature test DI 604 according to the present embodiment, and corresponds to FIG. 7C here. FIG. 8B is a cross-sectional view taken along the line AA ′ shown in FIG.

  The temperature detection DI 604 according to the present embodiment has a collector-base short configuration of an NPN transistor. In FIG. 8, the emitter 501 and the collector 503 have the high impurity concentration region N + 405 as an electrode, and the base 502 and the sub-contact 504 have the high impurity concentration region P + 403 as an electrode. In the first embodiment, the temperature test DI 104 in FIG. 5 has a PNP configuration, and the cathode is connected to the terminal VSS 205 via the substrate resistor 108. On the other hand, in the NPN configuration according to the present embodiment, N-404 having the same potential (connected) as the collector 503 surrounds the anode (connected to the base 502) P-402 and the cathode (emitter 501) N + 405. It is also formed in a deep position. Therefore, the anode and the cathode (emitter 501) are electrically separated from the terminal VSS 205 (P-type silicon substrate 401 and P-402).

  FIG. 7A shows a configuration according to the present embodiment in the NPN temperature test DIs 604-1, 604-2, and 604-3 (hereinafter collectively referred to as 604), which is the same as the first embodiment. The signal amplifying circuit 125 can be reduced in cost by increasing the potential of the terminal DIK 206 with respect to the GND 126. In the first embodiment, since the substrate resistance 108 is used, no special resistance element is required. On the other hand, in the configuration shown in FIG. 7A, the resistance element 708 is separately used. A configuration in which the resistance element 708 is further reduced from the configuration shown in FIG. 7A is the configuration in FIG. In the configuration of FIG. 7B, the resistance element 709 is commonly connected to the cathodes of the plurality of temperature detection DIs 604. In the configuration of FIG. 7B, the number of resistance elements can be reduced compared to the configuration of FIG. 7A, and the cost can be reduced. As in the first embodiment, in the configuration shown in FIG. 7, each of the MUXs 705, 706, and 707 selects a connection destination according to a control signal from the control unit 127 provided on the electric board 121 side.

  In FIG. 7C, the current path selection MUX 710 is connected to the cathode side of the temperature detection DI 604. As in the first embodiment, each of the MUXs 706, 707, and 710 selects a connection destination in accordance with a control signal from the control unit 127 provided on the electric board 121 side. Since the MUX 710 has an on-resistance of the switch, by providing it on the cathode side, it can also serve to increase the cathode voltage like the resistance elements 708 and 709 of FIG. This configuration eliminates the need for a resistance element. In the temperature detection DI 604 using an NPN transistor, as in the first embodiment, the cost of the signal amplification circuit 125 is reduced, and both the accuracy of temperature detection and the improvement of throughput are compatible. It can be realized.

  In the configuration shown in the second embodiment, an example in which the signal amplifier circuit 125, the ADC 122, and the constant current source 123 are mounted on the electric substrate 121 is shown. However, the present invention is not limited to this, and these circuits may be mounted in the recording head substrate 101.

<Other embodiments>
The recording head substrate shown in the above embodiment may be provided in a scan type recording head or may be used in a full line type recording head. Further, it may be provided in a recording apparatus using a plurality of recording heads, or may be used in a recording apparatus provided with one recording head. Further, the form of the recording head substrate 101 is not limited to the form as shown in FIG. 1, but may be provided on a substrate or a circuit unit outside the recording head substrate 101 other than the heater 102. The recording element is not limited to a heater, and may be a light emitting element such as a piezo element or an LED.

DESCRIPTION OF SYMBOLS 101 ... Recording head board | substrate, 102 ... Heater, 103 ... Driver transistor, 104 ... Temperature detection DI, 105-107 ... MUX, 108 ... Substrate resistance, 120 ... Flexible substrate, 121 ... Electric substrate, 122 ... ADC, 123 ... Constant current Source, 125 ... signal amplifier

Claims (18)

A recording device,
A recording head substrate having a recording element for recording an image;
A driving element for driving the recording element;
An application circuit for applying a drive signal to the drive element;
A ground wiring to which the application circuit is connected;
A plurality of temperature sensors for detecting a temperature related to the recording head substrate, the ground wiring and the cathode side being connected via a resistor;
A first selection circuit for selecting one of the plurality of temperature sensors on the anode side of the plurality of temperature sensors;
A second selection circuit for selecting one of the plurality of temperature sensors on the cathode side of the plurality of temperature sensors;
A temperature signal that outputs a temperature signal according to the difference between the voltage on the anode side of the temperature sensor selected by the first selection circuit and the voltage on the cathode side of the temperature sensor selected by the second selection circuit An output circuit. The recording apparatus includes a control unit,
The recording apparatus according to claim 1, wherein the first and second selection circuits select a temperature sensor from the plurality of temperature sensors according to a signal from the control unit.   The recording apparatus according to claim 1, further comprising means for acquiring a temperature value based on the temperature signal output circuit.   The recording apparatus according to claim 1, wherein a plurality of the recording elements are provided on the recording head substrate.   The recording apparatus according to claim 1, wherein the temperature signal output circuit includes a differential circuit.   The recording apparatus according to claim 1, wherein a plurality of resistors are provided corresponding to each of the plurality of temperature sensors.   2. The recording apparatus according to claim 1, wherein the temperature sensor includes any one of a diode connection configuration in which a base and a collector of a PNP transistor are short-circuited and a diode connection configuration in which a base and a collector of an NPN transistor are short-circuited.   8. The recording apparatus according to claim 7, wherein the resistor is a Si substrate resistor configured between a collector and a sub contact of the PNP transistor.   The recording apparatus according to claim 1, wherein the resistor is composed of any one of polycrystalline silicon, a resistor of the same material as the recording element, and a Si substrate resistor. A recording head substrate,
A recording element;
A driving element for driving the recording element;
An application circuit for applying a drive signal to the drive element;
A ground wiring to which the application circuit is connected;
A plurality of temperature sensors disposed on the recording head substrate, the ground wiring and the cathode side being connected via a resistor;
A resistor connected between the cathode side of the plurality of temperature sensors and the ground wiring;
A first selection circuit for selecting one of the plurality of temperature sensors on the anode side of the plurality of temperature sensors;
A second selection circuit for selecting one of the plurality of temperature sensors on the cathode side of the plurality of temperature sensors;
An output unit for outputting the voltage on the anode side of the temperature sensor selected by the first selection circuit and the voltage on the cathode side of the temperature sensor selected by the second selection circuit; A recording head substrate.   The recording head substrate according to claim 10, wherein the first and second selection circuits select a temperature sensor that performs temperature detection from the plurality of temperature sensors according to an external signal. .   11. The apparatus according to claim 10, further comprising a third selection circuit that is provided between a power supply source and anode sides of the plurality of temperature sensors and selects a temperature sensor that is the power supply destination. The recording head substrate as described.   The recording head substrate according to claim 10, wherein the resistor is configured by a third selection circuit for switching connection between any one of the plurality of temperature sensors and the ground wiring.   The recording head substrate according to claim 10, wherein a plurality of the resistors are provided corresponding to each of the plurality of temperature sensors.   11. The recording head according to claim 10, wherein the temperature sensor includes any one of a diode connection configuration in which a base and a collector of a PNP transistor are short-circuited and a diode connection configuration in which a base and a collector of an NPN transistor are short-circuited. substrate.   16. The recording head substrate according to claim 15, wherein the resistor is a Si substrate resistor configured between a collector and a sub contact of the PNP transistor.   The recording head substrate according to claim 10, wherein the resistor is composed of any one of polycrystalline silicon, a resistor of the same material as the recording element, and a Si substrate resistor.   The recording head substrate according to claim 10, wherein a plurality of the recording elements are provided in the recording head substrate.

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