Recording device

Abstract

To provide a recording device that can switch an amplification factor of a circuit that amplifies residual vibration voltages due to residual vibration after driving a piezoelectric element, with a simple structure.SOLUTION: A recording device comprises an amplifying part that amplifies and outputs residual vibration voltages and a setting part that sets an amplification factor at which the residual vibration voltages are amplified by the amplifying part. The amplifying part comprises an operational amplifier, and a selecting part that has first resistance that is connected to the operational amplifier and a plurality of second resistances having different resistance values that are connected to the operational amplifier a plurality of switches, which selects any one of the plurality of switches in accordance with the amplification factor set by the setting part to connect any one of the plurality of second resistances to the operational amplifier. The amplifying part amplifies the residual vibration voltages at an amplification factor corresponding to a resistance ratio between the first resistance and the second resistance selected by the selecting part.SELECTED DRAWING: Figure 15

Description

Technical Field

[0001] The present invention relates to an inkjet recording apparatus.

Background Art

[0002] Some inkjet recording apparatuses include a recording head that discharges ink by driving a piezoelectric element, and perform recording with the ink discharged from the recording head. A technique has been proposed for detecting an abnormality in each nozzle by detecting and analyzing a residual vibration voltage caused by residual vibration generated after driving the piezoelectric element. In Patent Document 1, a circuit for amplifying and analyzing a residual vibration voltage with an operational amplifier has been proposed. However, in Patent Document 1, the amplification factor of the circuit for amplifying the residual vibration voltage is fixed. Therefore, a signal amplitude necessary for analysis cannot be obtained for the residual vibration voltage that varies depending on the surrounding environment of the inkjet head, the state of the ink, etc., and an abnormality in the nozzle may not be detected. In Patent Document 2, a first resistor and a second resistor for switching the amplification factor of the circuit for amplifying the residual vibration voltage are prepared, each of the first resistor and the second resistor includes a plurality of resistor elements, and the amplification factor is switched by changing the number of those resistors.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technology described in Patent Document 2, the circuit configuration is complex, which may lead to an increase in cost. An object of the present invention is to provide a recording apparatus capable of switching the amplification factor of a circuit that amplifies the residual vibration voltage caused by residual vibration after driving a piezoelectric element with a simple configuration.

Means for Solving the Problems

[0005] The present invention is a recording apparatus including a piezoelectric element and a recording head that discharges a liquid by driving the piezoelectric element, and performs recording with the liquid discharged from the recording head, an amplification unit that amplifies and outputs a residual vibration voltage caused by residual vibration generated in the piezoelectric element after the piezoelectric element is driven by a drive signal, a setting unit that sets an amplification factor of the residual vibration voltage by the amplification unit, and is provided with The amplification unit includes an operational amplifier, a first resistor connected to the operational amplifier, a plurality of second resistors having different resistance values and connected to the operational amplifier via respective ones of a plurality of switches, and has The recording apparatus includes a selection unit that selects any one of the plurality of second resistors and connects it to the operational amplifier by selecting any one of the plurality of switches according to the amplification factor set by the setting unit, The amplification unit amplifies the residual vibration voltage at an amplification factor corresponding to a resistance ratio between the first resistor and the second resistor selected by the selection unit. The recording apparatus is characterized by this.

Effects of the Invention

[0006] According to the present invention, it is possible to provide a recording apparatus capable of switching the amplification factor of a circuit that amplifies the residual vibration voltage caused by residual vibration after driving a piezoelectric element with a simple configuration.

Brief Description of the Drawings

[0007]

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Embodiments for Carrying Out the Invention

[0008] Hereinafter, exemplary embodiments for carrying out the present invention will be described with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the following examples should be appropriately changed according to the configuration of the apparatus to which the present invention is applied and various conditions, and are not intended to limit the scope of the present invention to the following examples.

[0009] <Overall Configuration of the Recording Apparatus> FIG. 1 is a side sectional view showing the configuration of a recording apparatus 1 that performs recording on a roll-shaped recording medium such as roll paper using a full-line inkjet recording head as an example of an inkjet recording apparatus. The full-line inkjet recording head (hereinafter referred to as the "recording head") is a recording head having a recording width equal to or greater than the length in the width direction of the roll paper. As shown in FIG. 1, this recording apparatus 1 generally includes a housing 106, a head unit 100, first to fourth recording heads 101 corresponding to, for example, four colors of CMYK, a scanner unit 102, a line scanner 103, and a transport roller 104. The roll paper 105 used as the recording medium is nipped by the paired transport rollers 104 and transported in the direction of the arrow, and recording is sequentially performed directly below each of the first to fourth recording heads 101.

[0010] <Configuration of the recording head> As a means for ejecting ink from the nozzles of the recording head 101, a method is known in which a piezoelectric element is used as a discharge energy generating element to generate pressure in a pressure chamber, and the liquid in the pressure chamber is discharged from a nozzle formed at one end of the pressure chamber by that pressure. The recording apparatus 1 performs recording with the ink ejected from the nozzles of the recording head 101. In such a recording head 101, each piezoelectric element is provided with an electrical contact and is connected to an integrated circuit that generates a drive signal, and discharge is performed by driving the piezoelectric element with the drive signal.

[0011] FIG. 2 is a schematic diagram of a unit 209 in which a piezoelectric element substrate 200, a drive element selection unit 201, and a flexible printed wiring board 202 are combined. The piezoelectric element substrate 200 includes a first terminal 200a and a second terminal 200b, and is electrically connected to terminals (not shown) provided in the drive element selection unit 201 mounted on the flexible printed wiring board 202, respectively. The flexible printed wiring board 202 includes a selection unit side terminal 203 and is electrically connected to a wiring board side terminal (not shown) provided in the drive element selection unit 201.

[0012] The flexible printed wiring board 202 includes a capacitor region 205 for mounting a power supply bypass capacitor of the drive element selection unit 201, and a head substrate connection portion 204 for connecting to a head substrate (not shown).

[0013] FIG. 3 is a schematic diagram of the recording head 101. One recording head 101 is composed of four units 209. The electrical connection between each unit 209 and the head substrate 206 is performed by the head substrate connection portion 204. The head substrate 206 includes a signal connection portion 207 and a drive signal connection portion 208 that are connected to the main body of the recording apparatus 1.

[0014] FIG. 4 shows the wiring of the first layer of the flexible printed wiring board 210. The first drive signal wiring 211, the third drive signal wiring 213, the fifth drive signal wiring 215, and the seventh drive signal wiring 217 all have substantially the same wiring width. Drive signal feedback current lines 219 are arranged on the side opposite to the third drive signal wiring 213 of the first drive signal wiring 211 and on the side opposite to the fifth drive signal wiring 215 of the seventh drive signal wiring 217.

[0015] FIG. 5 shows the wiring of the second layer of the flexible printed wiring board 210. The second drive signal wiring 212, the fourth drive signal wiring 214, the sixth drive signal wiring 216, and the eighth drive signal wiring 218 all have substantially the same wiring width. Drive signal feedback current lines 219 are arranged on the side opposite to the fourth drive signal wiring 214 of the second drive signal wiring 212 and on the side opposite to the sixth drive signal wiring 216 of the eighth drive signal wiring 218.

[0016] <Explanation of the driving method of the piezoelectric element and the driving signal of the piezoelectric element> The driving method of the piezoelectric element 301 and the driving signal applied to the piezoelectric element 301 will be described with reference to FIG. 6. The driving of the piezoelectric element 301 has steps from (0) to (3) as shown in FIG. 6(a), and the applied voltage (driving signal) changes as shown in FIG. 6(b) in these steps. These will be described in order.

[0017] (0) In the initial state, the pressure chamber 304 is filled with ink 305, and a high voltage is applied from the voltage source 303 between the upper electrode 300 and the lower electrode 302 of the piezoelectric element 301, and the pressure chamber 304 is contracted.

[0018] (1) By reducing the voltage of the voltage source 303, the pressure chamber 304 is expanded to draw in the ink 305. At this time, a sinusoidal pressure wave is generated in the pressure chamber 304 by the piezoelectric element 301.

[0019] (2) By synchronizing with the pressure wave generated in (1) above and increasing the voltage of the voltage source 303, the pressure chamber 304 is contracted to eject the ink 305.

[0020] (3) After (2) above, the piezoelectric element 301 continues mechanical vibration. In order to cancel this mechanical vibration and make the piezoelectric element 301 stationary, the voltage of the voltage source 303 is increased again.

[0021] Through the steps from (0) to (3) above, one ejection operation is performed, and the above series of voltage changes of the voltage source 303 is the waveform of the drive signal to be applied to the piezoelectric element 301.

[0022] <Functional Configuration of the Recording Device> The functional configuration of the recording device 1 will be described. FIG. 7 is a block diagram showing the functional configuration of the recording device 1. Figure.

[0023] The Host PC 401 transmits print instructions and print data to the control controller 400. The control controller 400 that controls the recording device 1 has a reception I / F 402 for communicating with the Host PC 401, a CPU 410, and a ROM 403 that stores a program for operating the CPU 410. Further, the control controller 400 has a RAM 404 for executing programs and temporarily storing various data, and a motor / sensor control unit 405 for controlling the motors and sensors in the recording device 1. Also, the control controller 400 has an image processing unit 406 that performs image processing on the print data sent from the Host PC 401 through the reception I / F 402, and a recording control unit 407 that controls the recording head 101 based on the data processed by the image processing unit 406.

[0024] The image processing unit 406 generates raster image data that can be used for printing using the print data received from the Host PC 401, and converts it into image data for each ink color such as CMYK that can be processed by the recording control unit 407 and outputs it. The recording control unit 407 consists of a drive signal control unit 408 and a drive signal selection information transmission unit 409. The drive signal control unit 408 transmits a control signal for generating a drive signal to the drive signal generation unit 411. The drive signal selection information transmission unit 409 transmits drive signal selection information to the drive signal selection unit 412 through serial communication 1.

[0025] The drive signal generation unit 411 outputs a plurality of drive signals to the drive signal selection unit 412 based on the control signal transmitted from the drive signal control unit 408. The drive signal selection unit 412 selects a plurality of drive signals input from the drive signal generation unit 411 based on the drive signal selection information transmitted from the drive signal selection information transmission unit 409, and inputs them to the piezoelectric elements 301 corresponding to the nozzles in the head unit 100. When a voltage of the drive signal waveform is applied to the electrodes of the piezoelectric element 301, the piezoelectric element 301 between the electrodes is displaced, and ink is ejected from the nozzles using the ejection energy generated thereby.

[0026] The serial communication 1 between the drive signal selection information transmission unit 409 and the drive signal selection unit 412 is composed of a clk signal, a data signal, and a latch signal. Information is transmitted by loading it onto the data signal in synchronization with clk, and information is transmitted in units of the latch signal.

[0027] The serial communication 2 between the drive signal selection information transmission unit 409 and the drive signal selection unit 412 is used to set various setting information for the drive signal selection unit 412 to operate with respect to the internal setting register 508 (see FIG. 9) of the drive signal selection unit 412. Although a communication protocol such as SPI (Serial Peripheral Interface), which is generally widely known, is used, the communication method is not limited to this.

[0028] The abnormality detection unit 413 acquires the residual vibration voltage of the piezoelectric element 301 detected and amplified by a residual vibration detection circuit 511, which will be described later, from the drive signal selection unit 412, and performs abnormality detection of the ejection unit having the piezoelectric element 301 based on the residual vibration voltage.

[0029] The recording head 101 is composed of a nozzle having a mechanism for ejecting ink and a piezoelectric element 301 corresponding to the nozzle, and ejects ink by inputting a drive signal to the piezoelectric element 301 corresponding to the nozzle. Here, the recording head 101 is assumed to be composed of 128 nozzles and piezoelectric elements 301 corresponding to the nozzles. Note that the number of nozzles is an example and is not limited to this.

[0030] FIG. 8 is a diagram showing details of the processing content of the image processing unit 406 in FIG. 7. The image processing input unit 421 captures print data and outputs it to the image generation unit 422. The image generation unit 422 converts the print data into CMYK data with a resolution that can be recorded by the recording head 101 and outputs it. The output gradation correction processing unit 423 performs correction processing corresponding to the output characteristics of the ink.

[0031] The quantization processing unit 424 performs processing to convert data with 8-bit to 16-bit gradation into gradation that can be represented by the nozzles of the recording head 101. Generally, it performs N-value quantization using an error diffusion method or a dither method to convert the gradation into image data with 1-bit to 4-bit gradation. The landing position deviation correction processing unit 425 performs data shifting in pixel units so as to correct the landing position deviation for each nozzle in units of the image resolution. The image processing output unit 426 performs processing to output the result of image processing.

[0032] <Explanation of the drive signal selection unit> The drive signal selection unit 412 will be explained with reference to FIG. 9. The data transmitted through the serial communication 1 (clk / data / latch) from the drive signal selection information transmission unit 409 is received by the serial-parallel conversion unit 506 and held in the data latch 507 starting from the input timing of the latch signal. The held drive signal selection information is input to the decoder 509.

[0033] Also, the drive signal generation unit 411 is composed of a plurality of digital-to-analog conversion units 512 and a plurality of drive signal generation circuits 513. The digital-to-analog conversion unit 512 receives a control signal from the drive signal control unit 408. The drive signal generation circuit 513, which receives the output analog signal of the digital-to-analog conversion unit, generates a drive signal.

[0034] The generated drive signal is input through the head substrate 206 and the flexible electrical wiring substrate 202 to the switch group 510 in the drive signal selection unit 412 mounted on the flexible electrical wiring substrate 202. The switch group 510 is composed of a plurality of switches SWx-y (x corresponds to the nozzle number and y corresponds to the drive signal number), and selects a drive signal from among the plurality of drive signals based on the decoding information of the decoder 509 to drive the piezoelectric element 301 corresponding to the nozzle.

[0035] The drive signal generation unit 411 is a generation unit that generates a plurality of drive signals corresponding to a plurality of drive patterns of the piezoelectric element 301. The plurality of drive patterns are, for example, large ink droplet size, small ink droplet size, no ink droplet ejection, and the like. The drive signal selection information transmission unit 409 is a designation unit that designates a drive signal for driving the piezoelectric element 301 among the plurality of drive signals generated by the drive signal generation unit 411. The drive signal selection unit 412 is a switch unit that outputs the drive signal designated by the drive signal selection information transmission unit 409 to the piezoelectric element 301 among the plurality of input drive signals.

[0036] The recording head 101 consists of, as an example, 128 nozzles and piezoelectric elements 301 corresponding to each nozzle, and there are as many decoders 509 and switch groups 510 as the number of nozzles.

[0037] <Explanation of Serial Communication 1> FIG. 10 shows the content of Serial Communication 1 output from the drive signal selection information transmission unit 409. The data signal is transmitted in synchronization with the clk signal, and the latch signal indicates the end of one transmission.

[0038] The data signal does not have to be one. In order to match the ink ejection frequency, the number of data signals may be increased in balance with the frequency of the clk signal. Here, it is assumed that communication is performed so that data for one column, that is, data for the number of nozzles × drive signal selection information, can be transmitted between latch signals. For example, when there are 4 types of drive signals and the number of nozzles is 128, data for 128 × 2 bits (selection of 4 types) is transmitted. When there is a residual vibration detection switch described later, since there are 4 types + 1 residual vibration detection = 5 states, data for 128 × 3 bits (selection of 5 states) is transmitted.

[0039] <Drive Signal Selection Unit Timing Chart> Figure 11 shows the relationship between the data of serial communication 1 and the drive signal. Between the latch signals, drive signal selection information for one column (for all nozzle numbers) is transferred, and the received data is held in the data latch 507 of FIG. 9 starting from the latch signal. Based on the held data, the four input drive signals are selected for each nozzle and applied to the piezoelectric element 301 corresponding to the nozzle. For the four drive signal generation circuits 513, drive signals that can realize desired ink droplet states such as large ink droplet size, small ink droplet size, and no ink droplet ejection are assigned and used.

[0040] <Explanation of drive signal generation circuit> Figure 12 is a diagram for explaining the drive signal generation circuit 513 that generates a drive signal. The drive signal generation circuit 513 is a so-called amplifier circuit that amplifies the voltage and current of the analog signal 608 supplied to the non-inverting input terminal of the operational amplifier 607.

[0041] The drive signal generation circuit 513 is composed of transistors 601 and 602 connected in Darlington configuration on the high side, transistors 603 and 604 connected in Darlington configuration on the low side, and an operational amplifier 607. Transistors 601 and 602 are npn transistors, and transistors 603 and 604 are pnp transistors. The base terminals of transistors 602 and 604 are connected to the output terminal of the operational amplifier 607 via diodes, and the emitter terminals of transistors 601 and 603 are connected to the piezoelectric element 301 via a switch SWx-n (not shown). References 605 and 606 indicate the power supply voltage.

[0042] In the above configuration, when the analog signal 608 is input to the drive signal generation circuit 513, the voltage of the analog signal 608 is amplified by the operational amplifier 607. Next, the current is amplified by transistors 601, 602, and transistors 603, 604. The piezoelectric element 301 is driven by the drive signal 610 amplified in both voltage and current, and the ink is ejected.

[0043] <Explanation of residual vibration detection circuit> Among the switches SWx-y included in the switch group 510 of FIG. 9, the switches from SWx-0 to SWx-n are switches for applying a drive signal to the piezoelectric element 301 corresponding to the nozzle. On the other hand, the switch SWx-z is a switch for supplying the residual vibration voltage generated in the piezoelectric element 301 to the residual vibration detection circuit 511 due to the residual vibration after the piezoelectric element 301 is driven. The residual vibration detection circuit 511 is a detection unit that detects the residual vibration voltage resulting from the residual vibration generated in the piezoelectric element 301 after the piezoelectric element 301 is driven by a specified drive signal. The residual vibration detection circuit 511 has an amplification unit that amplifies and outputs the detected residual vibration voltage.

[0044] As shown in FIG. 13, a drive signal is applied to the piezoelectric element 301 to drive the piezoelectric element 301 (st1 section). Thereafter, the piezoelectric element 301 is disconnected from the drive signal. Then, a vibration voltage such as Amp-in in FIG. 13 appears in the piezoelectric element 301. This is the mechanical vibration remaining in the piezoelectric element 301 converted into voltage by the piezoelectric effect and is called the residual vibration voltage (st2 section). By detecting and analyzing the residual vibration voltage, abnormalities in each nozzle can be detected.

[0045] Here, for comparison with the embodiment, the details of the residual vibration detection circuit 511 according to the comparative example will be described with reference to FIG. 14. In FIG. 14, the residual vibration voltage Amp-in is supplied to the non-inverting input terminal V+ of the operational amplifier OPAz via the switch SWx-z and the capacitor Ca. Also, the V+ terminal of OPAz is connected to the bias voltage Vbias via the resistor Rm. On the other hand, the inverting input terminal V- of OPAz is connected to Vbias via the resistor Rb. Further the inverting input terminal V- of OPAz is connected to the output terminal of the operational amplifier OPAz via the resistor Ra.

[0046] In the above circuit, the residual vibration voltage Amp-in is amplified and becomes the residual vibration detection voltage Vz. The residual vibration detection voltage Vz is represented by Equation (1).

Equation

[0047] The residual vibration detection voltage Vz is sent out of the residual vibration detection circuit 511. Thereafter, the residual vibration detection voltage Vz is converted into a digital signal by an analog-to-digital conversion device and analyzed by a logic operation element (not shown).

[0048] FIG. 15 is a diagram showing the configuration of the residual vibration detection circuit 511 in the embodiment. The circuit shown in FIG. 15 is obtained by adding switches SW1 to SW4 to the circuit shown in FIG. 14 and making the gain of the operational amplifier OPAz changeable by resistors Rb1 to Rb4 selected by the switches SW1 to SW4. The gain of the operational amplifier OPAz is the coefficient of the residual vibration voltage Amp-in in the above-described formula (1) and is represented by the following formula (2).

Equation

[0049] For example, when Ra = 10 kΩ and Rb = 1 kΩ, the gain of the operational amplifier OPAz is 11 (times) from formula (2).

[0050] In FIG. 15, a first resistor Ra is connected between the inverting input terminal V− and the output terminal of the operational amplifier OPAz. One ends of second resistors Rb1 to Rb4 are connected to the inverting input terminal V− of the operational amplifier OPAz, and the other ends of the second resistors Rb1 to Rb4 are respectively connected to one ends of switches SW1 to SW4. The sides of switches SW1 to SW4 not connected to the second resistors Rb1 to Rb4 are all connected to the bias voltage Vbias. The second resistors Rb1 to Rb4 are a plurality of resistors having different resistance values connected to the operational amplifier OPAz via a plurality of switches SW1 to SW4.

[0051] Here, the number of the switches and the resistors Rbn (n: natural number) between the inverting input terminal V− selected by the switches and the bias voltage Vbias is described as four, but the number of the switches and the resistors Rbn selected by the switches is not limited to four.

[0052] In the above, switch SW1 is a switch that turns on when switch selection signal S1 among switch selection signals S1 to S4 output from switch selection unit 722 is at a Hi level and turns off when it is at a Lo level. Similarly, switches SW2 to SW4 are controlled to turn on and off by switch selection signals S2, S3, and S4, respectively.

[0053] The switch selection unit 722 receives setting signals GSELm (m = 0, 1) output from the gain setting signal output unit 721, and is a circuit that sets one of the switch selection signals S1 to S4 to a Hi level and the others to a Lo level according to the input signals.

[0054] What to output as the setting signal GSELm (which switch to select to determine the gain of the operational amplifier OPAz) is determined as follows, for example. That is, it is determined according to the ink temperature detected by detection means (not shown), the ink type (ink color, composition), information on the environment (temperature, humidity, etc.) in which the recording apparatus 1 is used, and the like. Specifically, the output data of the setting signal GSELm is determined by setting a predetermined value to the setting register 508.

[0055] The gain setting signal output unit 721 is a setting unit that sets the amplification factor of the residual vibration voltage in the residual vibration detection circuit 511. The switch selection unit 722 is a selection unit that selects one of the plurality of switches SW1 to SW4 according to the amplification factor set by the gain setting signal output unit 721 and connects one of the plurality of second resistors Rb1 to Rb4 to the operational amplifier OPAz. Thereby, the residual vibration detection circuit 511 amplifies the residual vibration voltage at an amplification factor (represented by Equation (2)) according to the resistance ratio of the first resistor Ra and the second resistor Rbn selected by the switch selection unit 722. The gain setting signal output unit 721 sets the amplification factor according to at least any one of the ink type, the ink temperature, and the information on the environment in which the recording apparatus 1 is used.

[0056] FIG. 16 is a diagram showing the correspondence relationship between the setting signal, the output signals (switch selection signals S1 to S4) of the switch selection unit 722, the resistors Rbn (n: natural number) selected by the switch selection signals S1 to S4, and the gain of the operational amplifier OPAz determined by the selected resistor Rbn. In the embodiment, the setting signal is a combination of GSEL0 and GSEL1. Using 2-bit input data, one of the four switches is selected, and as a result, one resistor Rbn (n: an integer from 1 to 4 here) connected to the inverting input terminal of the operational amplifier OPAz is selected. Along with the selection of the resistor Rbn, the gain of the operational amplifier OPAz can be switched in four steps as shown in FIG. 16.

[0057] In the embodiment, since an example with four selected switches is used for explanation, the necessary setting signals GSELm (m: integer greater than or equal to 0) are 2 bits (GSEL0 and GSEL1). However, the number of setting signals GSELm (number of bits) increases or decreases according to the number of switch selection signals (= number of switches). For example, if the number of GSELm is 3 (3 bits), the number of selectable switches is 8.

[0058] The disclosure of this embodiment includes the following configurations. (Configuration 1) A recording apparatus comprising a piezoelectric element and a recording head that discharges a liquid by driving the piezoelectric element, and performing recording with the liquid discharged by the recording head, an amplification unit that amplifies and outputs a residual vibration voltage caused by residual vibration generated in the piezoelectric element after the piezoelectric element is driven by a drive signal, a setting unit that sets an amplification factor of the residual vibration voltage by the amplification unit, and comprising, The amplification unit includes an operational amplifier, a first resistor connected to the operational amplifier, a plurality of second resistors having different resistance values connected to the operational amplifier via each of a plurality of switches, and having, The recording device includes a selection unit that selects any one of the plurality of switches according to the amplification factor set by the setting unit, and connects any one of the plurality of second resistors to the operational amplifier. The amplification unit amplifies the residual vibration voltage at an amplification factor according to the resistance ratio between the first resistor and the second resistor selected by the selection unit. A recording device characterized in that the residual vibration voltage is amplified at an amplification factor according to the resistance ratio between the first resistor and the second resistor selected by the selection unit. (Configuration 2) The recording device according to Configuration 1, wherein an abnormality of the recording head is detected based on the residual vibration voltage amplified by the amplification unit. (Configuration 3) The setting unit sets the amplification factor according to at least any one of the type of the liquid, the temperature of the liquid, and information on the environment in which the recording device is used. (Configuration 4) The recording device according to any one of Configurations 1 to 3, further comprising a generation unit that generates a plurality of drive signals according to a plurality of drive patterns of the piezoelectric element. (Configuration 5) A designation unit that designates a drive signal for driving the piezoelectric element among the plurality of drive signals, A switch unit that outputs the drive signal designated by the designation unit among the plurality of input drive signals to the piezoelectric element, The recording device according to Configuration 4, having the above.

Explanation of Reference Numerals

[0059] 1: Recording device, 101: Recording head, 301: Piezoelectric element, 409: Drive signal selection information transmission unit, 411: Drive signal generation unit, 412: Drive signal selection unit, 511: Residual vibration detection circuit, 721: Gain setting signal output unit, 722: Switch selection unit, Ra: First resistor, Rb1 to Rb4: Second resistors, OPAz: Operational amplifier

Claims

1. A recording apparatus comprising a piezoelectric element and a recording head that discharges a liquid by driving the piezoelectric element, and performing recording with the liquid discharged from the recording head, an amplification unit that amplifies and outputs a residual vibration voltage caused by residual vibration generated in the piezoelectric element after the piezoelectric element is driven by a drive signal, a setting unit that sets an amplification factor of the residual vibration voltage by the amplification unit, comprising, the amplification unit, an operational amplifier, a first resistor connected to the operational amplifier, a plurality of second resistors having different resistance values connected to the operational amplifier via respective ones of a plurality of switches, having, the recording apparatus includes a selection unit that selects any one of the plurality of second resistors and connects it to the operational amplifier by selecting any one of the plurality of switches according to the amplification factor set by the setting unit, the amplification unit amplifies the residual vibration voltage at an amplification factor corresponding to a resistance ratio between the first resistor and the second resistor selected by the selection unit. The recording apparatus is characterized by this.

2. The recording apparatus according to claim 1, wherein an abnormality of the recording head is detected based on the residual vibration voltage amplified by the amplification unit.

3. The recording apparatus according to claim 1 or 2, wherein the setting unit sets the amplification factor according to at least any one of the type of the liquid, the temperature of the liquid, and information on the environment in which the recording apparatus is used.

4. The recording apparatus according to claim 1 or 2, further comprising a generation unit that generates a plurality of drive signals corresponding to a plurality of drive patterns of the piezoelectric element.

5. a designation unit that designates a drive signal for driving the piezoelectric element among the plurality of drive signals, a switch unit that outputs the drive signal designated by the designation unit among the plurality of input drive signals to the piezoelectric element, having. The recording apparatus according to claim 1 or 2.

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