# US 9,039,115 B2 · Liquid ejecting apparatus

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- Number: US 9,039,115 B2
- Document ID: US9039115B2
- Status: Granted
- Kind: B2
- Application number: 14/527,070
- Filed: 2014-10-29
- Published: 2015-04-30
- Granted: 2015-05-26
- Earliest claimed: 2014-10-29
- Assignees: Seiko Epson Corporation
- Applicants: Seiko Epson Corporation
- Inventors: Junhua Zhang
- Web page: https://patentgrep.com/patent/US9039115B2

## CPC

- B41J 2/04588: {using a specific waveform}
- B41J 2/04581: {controlling heads based on piezoelectric elements}
- B41J 2/16526: {by applying pressure only}
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS

## Abstract

A maintenance pulse is a pulsed waveform that includes an expansion element that causes a pressure chamber to expand, a contraction element that causes the pressure chamber that is expanded by the expansion element to contract, and a reexpansion element that causes the pressure chamber that is contracted by the contraction element to expand again, and satisfies the following condition (1) when a time from the beginning of the contraction element to the beginning of the reexpansion element is given the term T1, and a specific vibration period that is caused in the liquid inside the pressure chamber is given the term Tc. 1.2×Tc≦T1<1.5×Tc (1)

## Claims

### Claim 1

A liquid ejecting apparatus comprising:
a liquid ejecting head that has a pressure chamber, which is in communication with a nozzle, and a pressure generation unit that brings about a pressure fluctuation in a liquid inside the pressure chamber, and is capable of ejecting the liquid from the nozzle through actuation of the pressure generation unit; and
a driving signal generation unit that causes a maintenance driving signal, which includes a maintenance pulse that causes the liquid to be ejected from the nozzle, to be generated during maintenance,
wherein the maintenance pulse is a pulsed waveform that includes an expansion element that causes the pressure chamber to expand, a contraction element that causes a pressure chamber that is expanded by the expansion element to contract, and a reexpansion element that causes a pressure chamber that is contracted by the contraction element to expand again, and
satisfies
1.2×Tc≦T1<1.5×Tc (1)
when a time from a beginning of the contraction element to a beginning of the reexpansion element is given the term T1, and a specific vibration period that is caused in the liquid inside the pressure chamber is given the term Tc.

### Claim 2 (depends on 1)

The liquid ejecting apparatus according to claim 1,
wherein the maintenance pulse satisfies
0.2×Tc≦T2<0.5×Tc (2)
when a time from a beginning of the reexpansion element to an end thereof is given the term T2.

### Claim 3 (depends on 1)

The liquid ejecting apparatus according to claim 1,
wherein the maintenance pulse satisfies
0.1×Vh≦Vhm≦0.5×Vh (3)
when a change in voltage of the contraction element is given the term Vh, and a change in voltage of the reexpansion element is given the term Vhm.

### Claim 4 (depends on 1)

The liquid ejecting apparatus according to claim 1,
wherein a driving signal includes a microvibration pulse that brings about a pressure fluctuation in the liquid inside the pressure chamber to an extent at which liquid is not ejected from the nozzle, and
wherein, the maintenance pulse is applied to the pressure generation unit after the microvibration pulse is applied to the pressure generation unit.