Seiko Epson Corporation

Tetsuo Takagi

Hidekazu Uematsu

Yoichiro Kondo

Toru Kashimura

Hidehiko Yajima

A drive circuit includes a drive signal output circuit that outputs a drive signal supplied to the piezoelectric element and a first constant voltage signal that is constant at a first voltage value; a switch circuit having one end electrically coupled to an output terminal of the drive signal output circuit and the other end electrically coupled to the first terminal of the piezoelectric element, and a reference voltage signal output circuit that is electrically coupled to the second terminal of the piezoelectric element and outputs a second constant voltage signal which is constant at a second voltage value, in which before the reference voltage signal output circuit starts to output the second constant voltage signal, the one end and the other end of the switch circuit are controlled to be non-conductive, and the drive signal output circuit outputs the first constant voltage signal.

Drive circuit and liquid ejecting apparatus

A drive circuit includes a first voltage output circuit coupled to a first terminal and outputting a first voltage signal, a second voltage output circuit coupled to a second terminal and outputting a second voltage signal, and a drive signal output circuit coupled to the first terminal and outputting a drive signal. In a first mode, the second voltage output circuit outputs the second voltage signal and the drive signal output circuit outputs the drive signal whose voltage value varies. In a second mode, the second voltage output circuit outputs the second voltage signal and the drive signal output circuit outputs the drive signal which is constant at a third voltage value. In a third mode, the first voltage output circuit outputs the first voltage signal and the second voltage output circuit outputs the second voltage signal.

There is provided a driving circuit that drives a discharge head which includes a piezoelectric element, the driving circuit including: a first voltage signal output circuit that outputs the first voltage signal by operating based on an amplification control signal; and an integrated circuit that outputs the amplification control signal, in which the integrated circuit includes an amplification control signal generation circuit, an output control circuit, and a first register, in which the amplification control signal generation circuit generates the amplification control signal based on a drive data that defines a signal waveform of the first voltage signal input from an input terminal, in which the first register holds an operating state data that defines the operating state of the driving circuit input from the input terminal, and in which the output control circuit controls an output of the driving circuit based on the operating state data.

Driving circuit, integrated circuit, and liquid discharge apparatus

There is a provided a drive circuit including a power supply voltage control circuit that controls supply of a power supply voltage to a first device and a second device, a first drive signal output circuit that includes a first detection circuit detecting a voltage value of the power supply voltage, and outputs a first drive signal, a second drive signal output circuit that includes a second detection circuit detecting the voltage value of the power supply voltage, and outputs a second drive signal, a first fuse having one end electrically coupled to a first detection circuit and a first selection circuit, and the other end electrically coupled to the power supply voltage control circuit, and a second fuse having one end electrically coupled to a second detection circuit and a second selection circuit, and the other end electrically coupled to the power supply voltage control circuit.

There is provided a driving circuit that drives a piezoelectric element, the driving circuit including an integrated circuit, in which the integrated circuit includes a first register that holds an operating state data, a second register that holds an abnormality detection data, an abnormality detection circuit that determines the presence or absence of an abnormality of the operating state data based on the abnormality detection data, and an output control circuit that controls supply of a first voltage signal to the piezoelectric element and supply of a power source voltage to the switch circuit, and in which the output control circuit delays stop of the supply of the power source voltage to the switch circuit with respect to stop of the supply of the first voltage signal to the piezoelectric element when the abnormality detection circuit determines that the operating state data is abnormal.

There is provided a driving circuit including: an integrated circuit, in which the integrated circuit includes an amplification control signal generation circuit that generates an amplification control signal, a first register that holds an operating state data indicating an operating state of the driving circuit, a second register that holds an abnormality detection data for determining the presence or absence of an abnormality in the operating state data, an abnormality detection circuit that determines whether or not the operating state data is abnormal based on the abnormality detection data, and generates an abnormality detection signal indicating the determination result; and an abnormality detection signal output control circuit that controls whether or not the abnormality detection signal is output, in which the abnormality detection signal output control circuit does not output the abnormality detection signal in a first mode to be shifted after power is turned on.

There is a provided a drive circuit in which a first drive signal output circuit includes a first control circuit that controls an output of a first drive signal, and a first abnormality detection circuit that detects an abnormality in a first drive signal output circuit, a second drive signal output circuit includes a second control circuit that controls an output of a second drive signal, and a second abnormality detection circuit that detects an abnormality in a second drive signal output circuit, the first drive signal output circuit transmits an occurrence of abnormality to the second drive signal output circuit, when the first abnormality detection circuit detects the abnormality, and the second drive signal output circuit transmits an occurrence of abnormality to the first drive signal output circuit, when the second abnormality detection circuit detects the abnormality.

There is provided a driving circuit that drives a piezoelectric element having a first electrode that is supplied a first voltage signal and a second electrode that is supplied a second voltage signal, and driven by a potential difference between the first electrode and the second electrode, the driving circuit including: a first voltage signal generation circuit that outputs the first voltage signal; a second voltage signal generation circuit that outputs the second voltage signal; and a switch circuit in which the first voltage signal is input from one end and the other end is electrically connected to the first electrode, a voltage value of the first voltage signal approaches a voltage value of the second voltage signal in a shift period from a first mode that is shifted after power is turned on to a second mode for driving the piezoelectric element.

Driving circuit, liquid discharge apparatus, and driving method

A liquid ejecting apparatus includes a drive circuit that outputs a drive signal, a piezoelectric element that includes a first electrode to which the drive signal is supplied and a second electrode to which a reference voltage signal is supplied and that is displaced by a potential difference between the first electrode and the second electrode, a cavity that is filled with a liquid ejected from a nozzle according to the displacement of the piezoelectric element, a vibration plate that is provided between the cavity and the piezoelectric element, a detection circuit that detects whether or not a voltage variation of the drive signal is within a predetermined range, and a determination circuit that determines whether or not the drive signal is normal based on a detection result of the detection circuit.

Liquid ejecting apparatus and drive signal generation circuit

A liquid ejecting apparatus includes a drive circuit that outputs a drive signal, a criterion voltage circuit that outputs a criterion voltage signal from a criterion voltage-signal output terminal, a piezoelectric element that includes a first electrode to which the drive signal is supplied and a second electrode to which the criterion voltage signal is supplied, a cavity, and a vibration plate which is provided between the cavity and the piezoelectric element. The criterion voltage circuit includes a voltage generation unit that generates the criterion voltage signal, and a voltage detection unit that detects a voltage value of the criterion voltage signal. In a case where the voltage value of the criterion voltage signal is greater than a first threshold, the voltage detection unit stops an operation of the voltage generation unit and electrically connects the criterion voltage-signal output terminal and a ground terminal to each other.

Liquid ejecting apparatus

A liquid ejecting apparatus includes a piezoelectric element that includes a first electrode to which a drive signal is supplied and a second electrode to which a criterion voltage signal is supplied, and performs displacement by a potential difference between the first electrode and the second electrode, a cavity which is filled with a liquid, a vibration plate provided between the cavity and the piezoelectric element, and a first switching circuit that includes a first terminal to which the drive signal is supplied and a second terminal which is electrically connected to the first electrode and controls a supply of the drive signal to the first electrode. The liquid ejecting apparatus has a first mode in which charges at a first node at which the first electrode and the second terminal are electrically connected to each other are released via a parasitic diode of the first switching circuit.

There is provided a driving circuit for driving a capacitive load including: a modulation portion which generates a modulation signal pulse-modulated from a source signal; a gate driver which generates an amplification control signal based on the modulation signal; a transistor which generates an amplification modulation signal amplified from the modulation signal based on the amplification control signal; a low pass filter which demodulates the amplification modulation signal and generates a driving signal; a feedback circuit which sends back the driving signal to the modulation portion; a boosting circuit which supplies a voltage which has been boosted.

Liquid discharging apparatus, head unit, integrated circuit device for capacitive load driving, capacitive load driving circuit, and control method of liquid discharging apparatus

A liquid discharge apparatus includes: an modulation circuit that generates a modulated signal by pulse-modulating a source signal through self-oscillation; a transistor that amplifies the modulated signal to generate an amplified modulated signal; a low-pass filter that includes an inductor and a capacitor and smoothes the amplified modulated signal to generate a drive signal; a feedback circuit that allows the drive signal to return to the modulation circuit; a piezoelectric element that is displaced by application of the drive signal thereto; a cavity that is filled with a liquid inside and has an internal volume which changes when the piezoelectric element is displaced; and a nozzle that is provided to discharge the liquid inside the cavity in response to the change of the internal volume of the cavity. In this configuration, a self-resonant frequency of the capacitor is higher than a frequency of the self-oscillation.

Drive circuit for driving a capacitive load

A drive circuit for driving a capacitive load is provided. The drive circuit includes a modulation circuit that generates a modulated signal by pulse-modulating a source signal through self-oscillation; a pair of transistors that include a high-side transistor and a low-side transistor and amplify the modulated signal to generate an amplified modulated signal; and a low-pass filter that includes a capacitor and smoothes the amplified modulated signal to generate a drive signal which is applied to the capacitive load, wherein the shortest distance between a low-side transistor and the capacitor is shorter than a shortest distance between the high-side transistor and the capacitor.

Driving circuit for driving a capacitive load

There is provided a liquid discharging apparatus including: a modulation portion which generates a modulation signal pulse-modulated from a source signal; a gate driver which generates an amplification control signal based on the modulation signal; a transistor which generates an amplification modulation signal amplified from the modulation signal based on the amplification control signal; a low pass filter which demodulates the amplification modulation signal and generates a driving signal; a feedback circuit which sends back the driving signal to the modulation portion; a boosting circuit which supplies a voltage which has been boosted based on any one of a first clock signal and a second clock signal to the gate driver; a boosting control portion which controls boosting in the boosting circuit; and a piezoelectric element which is displaced as the driving signal is applied.

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Okaya, Japan

Tetsuo Takagi