Liquid ejection head and liquid ejection apparatus
AssigneeCanon Kabushiki Kaisha
InventorYasunori Takei
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Abstract
A liquid ejection head and a liquid ejection apparatus are capable of efficiently ejecting a liquid having a viscosity of 2.5 cp or above at high frequency. To this end, a relation L≤H−0.4D is satisfied, where D is the thickness of an ejection port plate, H is the distance from an electrothermal conversion element to the outermost surface of the ejection port plate, and L is the height of an air bubble.
Claims8
A liquid ejection head comprising:
- an ejection port through which a liquid is ejected;
- and
- a pressure chamber that communicates with the ejection port and is provided with a thermal energy generating element at a position facing the ejection port, the liquid ejection head being configured to eject the liquid in a volume of 4 [pl] or more from the ejection port by generating and contracting an air bubble by application of heat from the thermal energy generating element to the liquid having a viscosity of 2.5 [cp] or higher in the pressure chamber, wherein
- in a direction in which the liquid is ejected from the ejection port, a relation L≤H−0.4D is satisfied, where
- D is a distance from a first opening portion to a second opening portion of a member forming the ejection port, the first opening portion opening toward the pressure chamber and the second opening portion being at a side where the liquid is ejected,
- H is a distance from the position where the thermal energy generating element is disposed to the second opening portion, and
- L is a distance from the thermal energy generating element to an air-liquid interface of the air bubble at a time when the air bubble is at a maximum volume in a liquid ejection process.
A liquid ejection head comprising:
- an ejection port through which a liquid is ejected;
- and
- a pressure chamber that communicates with the ejection port and is provided with a thermal energy generating element at a position facing the ejection port, the liquid ejection head being configured to eject the liquid in a volume of 4 [pl] or more from the ejection port by generating and contracting an air bubble by application of heat from the thermal energy generating element to the liquid having a viscosity of 2.5 [cp] or higher in the pressure chamber, wherein
- in a direction in which the liquid is ejected from the ejection port, relations H<40 [μm], D≥5 [μm], and H−D≥−0.22H+24.7 [μm] are satisfied, where
- D is a distance from a first opening portion to a second opening portion of a member forming the ejection port, the first opening portion opening toward the pressure chamber and the second opening portion being at a side where the liquid is ejected, and
- H is a distance from the position where the thermal energy generating element is disposed to the second opening portion.
A liquid ejection apparatus to which a liquid ejection head is attachable, the liquid ejection head including an ejection port through which a liquid is ejected and a pressure chamber that communicates with the ejection port and is provided with a thermal energy generating element at a position facing the ejection port, the liquid ejection head being configured to eject the liquid in a volume of 4 [pl] or more from the ejection port by generating and contracting an air bubble by application of heat from the thermal energy generating element to the liquid having a viscosity of 2.5 [cp] or higher in the pressure chamber, wherein
- in a direction in which the liquid is ejected from the ejection port, a relation L≤H−0.4D is satisfied, where
- D is a distance from a first opening portion to a second opening portion of a member forming the ejection port, the first opening portion opening toward the pressure chamber and the second opening portion being at a side where the liquid is ejected,
- H is a distance from the position where the thermal energy generating element is disposed to the second opening portion, and
- L is a distance from the thermal energy generating element to an air-liquid interface of the air bubble at a time when the air bubble is at a maximum volume in a liquid ejection process.
Dependencies are inferred from the claim text.