Claims
- 1. A method of ejecting a droplet of liquid from an orifice in a liquid-containing capillary, comprising the steps of:
- heating a portion of said liquid to a temperature which is below the boiling point of the liquid by passing an electrical precurser current pulse, which varies substantially as the square root of the inverse of time, through a resistor which is in thermal contact with said portion; and
- quickly heating said portion, by passing a subsequent electrical nucleation current pulse through the resistor, to a temperature above the boiling point of the liquid and near the superheat limit of the liquid to cause formation of a vapor bubble in said liquid-containing capillary, said vapor bubble causing a droplet of liquid to be ejected from said orifice.
- 2. A method as in claim 1 wherein said liquid comprises ink.
- 3. A method as in claim 1, wherein said precurser and nucleation current pulses are insufficient to cause vaporized liquid to escape from said orifice.
- 4. A method as in claim 3, wherein said liquid comprises ink.
Parent Case Info
This is a division of application Ser. No. 292,841, filed Aug. 14, 1981 now abandoned.
US Referenced Citations (8)
Divisions (1)
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Number |
Date |
Country |
Parent |
292841 |
Aug 1981 |
|