Seiko Epson Corporation

Semiconductor Technology Academic Research Center

Akira Abe

Hiroshi Sugita

Shoichiro Kasahara

Koichiro Mashiko

Tatsuji Matsuura

Yoshiyuki Kamihara

Haruo Kobayashi

Akira Nakada

Takeshi Kawasaki

Masato Kaneta

Kazuya Shimizu

Katsuyoshi Yagi

A driving circuit includes a comparator that compares a voltage of an original driving signal with a voltage of a feedback signal of a driving signal, transistors, and a control signal generating circuit that generates a gate signal to the transistor and a gate signal to the transistor. The control signal generating circuit controls to alternately switch on the transistors. Driving abilities of the transistors are switched to be lowered by insertion of capacitors by an adjustment circuit.

Liquid ejecting apparatus

Provided a liquid ejecting apparatus including: a head that includes a piezoelectric element which is displaced by application of a drive signal; a transistor pair that includes a high-side transistor and a low-side transistor and outputs the drive signal; and a control signal generation circuit which generates a first control signal that controls switching operation of the high-side transistor and a second control signal that controls switching operation of the low-side transistor, in which the high-side transistor is set to be on and thus a voltage of the drive signal rises, and the low-side transistor is set to be on and thus the voltage of the drive signal drops, and in which the control signal generation circuit generates the first control signal and the second control signal in such a manner that the high-side transistor and the low-side transistor are alternately set to be on.

Liquid ejecting apparatus and drive circuit

A drive circuit includes a first transistor pair, a second transistor pair, a feeder linefor a ground Gnd, a feeder lineto which a voltage Vis applied, a feeder linea voltage Vis applied, and capacitors Cag and Cba, and the first transistor pair amplifies a signal ain within a range from the ground Gnd to the voltage V, and the second transistor pair amplifies the signal ain within a range from the voltage Vto the voltage V, and one end of the capacitor Cag is connected to the feeder line, the other end of the capacitor Cag is connected to the feeder line, one end of the capacitor Cba is connected to the feeder line, and the other end of the capacitor Cba is connected to the feeder line

Liquid ejecting apparatus and capacitive load drive circuit

A liquid ejecting apparatus includes an ejecting unit that includes a piezoelectric element which is displaced by a drive signal; a differential amplifier that outputs a control signal based on a source drive signal which is a source signal of the drive signal and a signal based on the drive signal; a pair of transistors that include a high-side transistor and a low-side transistor which are controlled based on the control signal and outputs the drive signal from an output terminal; a selector that selects one of the high-side transistor and the low-side transistor and supplies the control signal to the selected transistor; a first resistance element for pulling up the output terminal; and a second resistance element for pulling down the output terminal. The first resistance element or the second resistance element has a variable resistance value.

Liquid ejecting apparatus, drive circuit, and head unit

A liquid ejecting device includes: an ejection section having a piezoelectric element that ejects liquid by being displaced upon application of a drive signal; a comparator having a first comparator section and a second comparator section, receiving an input signal and the drive signal, and outputting first and second control signals; and a transistor pair having a first transistor controlled with the first control signal and a second transistor controlled with the second control signal, and outputting the drive signal, the first comparator section comparing first and second comparison signals and outputting the first control signal, the first comparison signal being obtained by offsetting one of the input signal and the drive signal, the second comparator section comparing third and fourth comparison signals and outputting the second control signal, and the third comparison signal being obtained by offsetting one of the input signal and the drive signal.

Liquid ejecting device, driver circuit, and head unit

A liquid ejecting apparatus includes a drive circuit board on which a drive circuit which outputs a driving signal obtained by amplifying the original driving signal is mounted; an actuator substrate which includes an ejecting unit including a piezoelectric element which is driven by the driving signal, and ejects liquid when the piezoelectric element is driven; and a head unit a head unit on which a relay board which relays the driving signal to the piezoelectric element from the drive circuit board, the actuator substrate, the relay board, and the drive circuit board are mounted, and which is mounted on a carriage which reciprocates in an X direction as a main scanning direction. A mounting face of the drive circuit board is attached to the relay board so as to be placed in a direction which goes along the X direction in the main scanning direction of the carriage.

A drive circuit which drives a capacitive load on the basis of a drive signal output from a node includes a first wire; a second wire; an amplification unit; a capacitor and a resistance element; a determination unit which determines whether or not a voltage of a differentiated drive signal is within a predetermined range in case where a magnitude of a voltage change of the signal is less than or equal to a threshold; and a voltage output unit which amplifies the a voltage of the signal by a predetermined multiple, for example, one time, and outputs the amplified signal toward the node in a case where it is determined that the voltage of the differentiated drive signal is within the predetermined range.

Liquid ejecting apparatus, drive circuit, and driving method

A drive circuit includes a control signal generator configured to generate a control signal based on a drive signal and a source drive signal, and an amplifier including a high-side transistor and a low-side transistor controlled based on the control signal. The amplifier is configured to output the drive signal from an output terminal to drive a capacitive load during a first period in which a voltage of the drive signal changes to be higher than or equal to a first voltage per unit time and a second period in which the voltage changes to be lower than the first voltage or does not change per unit time. The first period includes a period in which one of the high-side and the low-side transistors performs a switching operation. The second period includes a period in which the one of the high-side and the low-side transistors performs a linear operation.

Drive circuit, and control method of drive circuit

A drive circuit includes an amplification unit that amplifies a signal and outputs the amplified signal toward a node; and a voltage output unit that outputs a voltage responding to the signal toward the node during a predetermined period of a part or all of a period in which a magnitude of a voltage change of the signal is less than or equal to a threshold. The amplification unit includes a differential amplifier, a selector, and transistors, and the voltage output unit includes a linear amplifier and a switch.

A drive circuit for driving a capacitive load includes a power supply unit that boosts a single voltage and includes multiple voltage boosting circuits which generate power supply voltages different from each other; a drive circuit that amplifies an original drive signal based on a power supply voltage which is generated by at least one of the multiple voltage boosting circuits and generates a drive signal; in which the power supply unit controls the voltage boosting circuit, which generates the power supply voltage that is not used for amplification, to stop voltage boosting.

A liquid ejecting apparatus includes an ejecting unit, a differential amplifier, a pair of transistors, and a selector. The ejecting unit includes a piezoelectric element which is configured to be displaced by a drive signal being applied to the piezoelectric element. The ejecting unit is configured to eject liquid in accordance with displacement of the piezoelectric element. The differential amplifier is configured to output a control signal based on a source drive signal which is a source signal of the drive signal and a signal based on the drive signal. The transistors includes a high-side transistor and a low-side transistor which are configured to be controlled based on the control signal and are configured to output the drive signal from an output terminal of the transistors. The selector is configured to select one of the high-side transistor and the low-side transistor and supply the control signal to a selected transistor.

A liquid ejecting apparatus includes an ejecting unit that includes a piezoelectric element which is displaced by a drive signal; a differential amplifier that outputs a control signal based can a source drive signal which is a source signal of the drive signal and a signal based on the drive signal; a pair of transistors that include a high-side transistor and a low-side transistor which are controlled based on the control signal and outputs the drive signal from an output terminal; and a selector that selects one of the high-side transistor and the low-side transistor and supplies the control signal to the selected transistor. The selector selects a transistor to which the control signal is supplied, based on a logic level of a predetermined select signal. The logic level of the select signal is inverted for a predetermined period.

A liquid ejecting apparatus includes an ejecting unit that includes a piezoelectric element which is displaced by application of a drive signal and ejects liquid according to displacement of the piezoelectric element; a comparison unit that includes a first comparator and a second comparator, receives an input signal and a feedback signal based on the drive signal, and outputs a first control signal and a second control signal; a pair of transistors that is configured by a first transistor which is controlled based on the first control signal and a second transistor which is controlled based on the second control signal, and outputs the drive signal from a coupling point of the first transistor and the second transistor; an output capacitor that has one terminal coupled to the coupling point; and a differentiation and integration circuit.

A liquid ejecting apparatus includes: a modulation circuit that generates a modulated signal obtained by performing pulse modulation on a source signal; a transistor that amplifies the modulated signal to generate an amplified modulated signal; a lowpass filer that smoothes the amplified modulated signal to generate a driving signal; a piezoelectric element that is displaced when the driving signal is applied; and a circuit substrate on which the modulation circuit, the transistor, and the lowpass filter are mounted. The transistor includes a die, a first electrode, a second electrode, a third electrode, a conductive die pad, a first lead which is electrically connected to the second electrode by a bonding wire, and a second lead which is electrically connected to the third electrode by a bonding wire. The die pad, the first lead, and the second lead are electrically connected to different wiring patterns of the circuit substrate.

Liquid ejecting apparatus, head unit, and method of controlling liquid ejecting apparatus

Provided is a driving circuit for driving a capacitive load which includes a modulation circuit which generates a modulation signal which is obtained by pulse-modulating a source signal, a transistor which generates an amplified modulation signal by amplifying the modulation signal, a low pass filter which generates a drive signal by smoothening the amplified modulation signal, a piezoelectric element which is displaced by receiving the drive signal, and a circuit substrate on which the transistor is mounted. The transistor includes a first electrode, a second electrode, a third electrode, and a clip which has conductivity, is electrically connected to the first electrode. Furthermore, the circuit substrate has a first land corresponding to the first electrode, a second land corresponding to the second electrode, and a third land corresponding to the third electrode. In addition, a part of the clip is connected to the third land.

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Matsumoto, Japan

Akira Abe